Patent Publication Number: US-7588653-B2

Title: Method of making an integrated window sash

Description:
RELATED APPLICATIONS 
   This application claims the benefit of U.S. Provisional Patent Application bearing Ser. No. 60/480,621 filed Jun. 23, 2003, which application in its entirety is incorporated herein. 
   This application is related to application Ser. No. 10/874,721 filed even date in the names of Stephen L. Crandell et al. for “Integrated Window Sash with Groove for Desiccant Material”; application Ser. No. 10/874,503 filed even date in the names of Barent A. Rosskamp et al. for “Integrated Window Sash with Lattice Frame and Retainer Clip”; application Ser. No. 10/874,682 filed even date in the names of Cory D. Steffek, et al. for “Integrated Window Sash”; and PCT Application Serial No. PCT/US2004/20182 filed even date in the names of Stephen L. Crandell et al. for “Integrated Window Sash and Methods of Making an Integrated Window Sash”, herein incorporated by reference. 

   FIELD OF THE INVENTION 
   This invention relates to an integrated window sash having an insulating viewing area, and in particular, to a window sash for maintaining two or more sheets, e.g. glass sheets, spaced from one another to provide a sealed gas containing compartment between adjacent sheets, and to a method of making an integrated window sash having an insulating vision area. 
   BACKGROUND OF THE INVENTION 
   One practice of fabricating a window sash having an insulating viewing or vision area includes fabricating an insulating glazing unit and mounting the glazing unit in an open area defined by a sash frame. As used throughout this document, the term “sash frame” means a framework made up of one or more straight and/or bent elongated sash members or lineals defining an enclosed open area, and the terms “sash” or “window sash” mean a sash frame having one or more sheets, e.g. but not limited to one or more glass sheets in the enclosed open area bound by the sash frame which area, when having one or more transparent sheets therein, provides a viewing area. The insulating unit can be made in any manner, for example, but not limited to the techniques disclosed in U.S. Pat. Nos. 5,177,916; 5,531,047; 5,553,440; 5,564,631; 5,617,699; 5,644,894; 5,655,282; 5,720,836; 6,115,989; 6,250,026, and 6,289,641. The adjacent sheets of the insulating units are maintained in a spaced relationship to one another by a spacer frame, and the inner marginal edges of the sheets are secured to the spacer frame by a gas and vapor resistant adhesive to provide a sealed gas space or compartment between the adjacent sheets. 
   In another practice, a glass sheet is secured to each of the ledges of two or more sheet supporting ledges of a sash frame to space the sheets from one another to provide an insulating vision area, for example, as disclosed in U.S. Pat. Nos. 5,653,073 and 6,055,783. 
   As can be appreciated by those skilled in the art of fabricating window sashes having insulating vision areas, eliminating the manufacturing steps to make an insulating unit significantly reduces the cost of manufacturing a window sash having an insulating viewing area. Although the presently available practices of fabricating window sashes having insulating viewing areas without prefabricated insulating glazing units are acceptable, it can be appreciated by those skilled in the art that it is advantageous to have additional techniques to fabricate such window sashes. 
   SUMMARY OF THE INVENTION 
   The invention relates to a method of making an integrated window sash. Non-limiting embodiments of the invention include the following. 
   A method of making an integrated window sash, including providing a sash frame having a first sheet supporting surface, a second sheet supporting surface, and a base extending from the first sheet supporting surface to toward the second sheet supporting surface; applying a layer of an adhesive sealant having a low gas and moisture permeability on the first sheet supporting surface; applying a layer of an adhesive sealant having a low gas and moisture permeability on the second sheet supporting surface; applying a layer of a moisture pervious matrix having a desiccant therein on the base; moving a first sheet having a first major surface and an opposite second major surface into the spacer frame over and spaced from the matrix to move the first major surface of the first sheet against the first layer, and moving a second sheet having a first major surface and an opposite major surface toward the second layer to move the first major surface of the second sheet against the second layer, wherein the first surface of the second sheet is spaced from the second surface of the first sheet to provide a compartment therebetween and the desiccant is in communication with the compartment. 
   A method of making an integrated window sash including providing a sash frame having a first sheet supporting surface, a second sheet supporting surface, and a base extending from the first sheet supporting surface to toward the second sheet supporting surface; applying a barrier layer comprising a film of a low gas and moisture permeability material at least on the base, the film selected from plastic and metal; applying simultaneoulsly or in any sequence a layer of an adhesive sealant having a low gas and moisture permeability on the first sheet supporting surface, a layer of an adhesive sealant having a low gas and moisture permeability on the second sheet supporting surface, and a layer of a moisture pervious matrix having a desiccant therein on the barrier layer; moving a first sheet having a first major surface and an opposite second major surface into the spacer frame over and spaced from the matrix to move the first major surface of the first sheet against the first layer, and moving a second sheet having a first major surface and an opposite major surface toward the second layer to move the first major surface of the second sheet against the second layer, wherein the first surface of the second sheet is spaced from the second surface of the first sheet to provide a compartment therebetween and the desiccant is in communication with the compartment. 
   A method of making an integrated window sash including feeding a plastic resin into a first material receiver of a co-extruder, an adhesive resin into a second receiver of the co-extruder and a barrier layer resin into a third receiver of the co-extruder; moving the resins through a die of the co-extruder to form a lineal having first and second sheet supporting surfaces interconnected by a base and a barrier layer secured to the base by the adhesive resin; cutting the lineal to provide a plurality of sash members; joining the ends of adjacent sash member to provide a sash frame; applying simultaneously or in any sequence a layer of a moisture impervious adhesive sealant on the first sheet supporting surface, a layer of moisture impervious adhesive sealant on the second sheet supporting surface, and a layer of a moisture pervious matrix having a desiccant therein on the base; moving a first sheet having a first major surface and an opposite second major surface into the spacer frame over and spaced from the matrix to move the first major surface of the first sheet against the first layer, and moving a second sheet having a first major surface and an opposite major surface toward the second layer to move the first major surface of the second sheet against the second layer, wherein the first surface of the second sheet is spaced from the second surface of the first sheet to provide a compartment there between and the desiccant is in communication with the compartment. 
   A method of making an integrated window sash including feeding a plastic resin into a material receiver of an extruder; moving the resin through a die of the extruder to form a lineal having first and second sheet supporting surfaces and a base having a surface the interconnects the first and second sheet supporting surfaces; securing a metal barrier layer to at least the surface of the base as the lineal is formed; cutting the lineal to provide a plurality of sash members; joining the ends of adjacent sash member to provide a sash frame; applying simultaneously or in any sequence a layer of a moisture impervious adhesive sealant on the first sheet supporting surface, a layer of moisture impervious adhesive sealant on the second sheet supporting surface, and a layer of a moisture pervious matrix having a desiccant therein on the base; moving a first sheet having a first major surface and an opposite second major surface into the spacer frame over and spaced from the matrix to move the first major surface of the first sheet against the first layer, and moving a second sheet having a first major surface and an opposite major surface toward the second layer to move the first major surface of the second sheet against the second layer, wherein the first surface of the second sheet is spaced from the second surface of the first sheet to provide a compartment therebetween and the desiccant is in communication with the compartment. 
   A method of making an integrated window sash, including providing continuous fiber glass strand through a forming die of a pultrusion device; feeding a polymeric material into a first material receiver of a pultrusion device, an adhesive material into a second receiver of the pultrusion device, and a barrier layer material into a third receiver of the pultrusion device; pulling the fiber glass strand through the die as the polymeric materials is formed around the strand to produce a lineal having first and second sheet supporting surfaces, a base having a surface the interconnects the first and second sheet supporting surfaces, and a barrier layer secured to the base by the adhesive material; cutting the lineal to provide a plurality of sash members; joining the ends of adjacent sash member to provide a sash frame; applying simultaneously or in any sequence a layer of a moisture impervious adhesive sealant on the first sheet supporting surface, a layer of moisture impervious adhesive sealant on the second sheet supporting surface, and a layer of a moisture pervious matrix having a desiccant therein on the base; moving a first sheet having a first major surface and an opposite second major surface into the spacer frame over and spaced from the matrix to move the first major surface of the first sheet against the first layer, and moving a second sheet having a first major surface and an opposite major surface toward the second layer to move the first major surface of the second sheet against the second layer, wherein the first surface of the second sheet is spaced from the second surface of the first sheet to provide a compartment therebetween and the desiccant is in communication with the compartment. 
   A method of making an integrated window sash, including providing continuous fiber glass strand through a forming die of a pultrusion device; feeding polymeric material into a material receiver of the pultrusion device; pulling the fiber glass strand through the die as the polymeric material is formed around the strand to produce a lineal having first and second sheet supporting surfaces and a base having a surface the interconnects the first and second sheet supporting surfaces; securing a metal barrier layer to at is least the surface of the base as the lineal is formed; cutting the lineal to provide a plurality of sash members; joining the ends of adjacent sash member to provide a sash frame; applying simultaneously or in any sequence a layer of a moisture impervious adhesive sealant on the first sheet supporting surface, a layer of moisture impervious adhesive sealant on the second sheet supporting surface, and a layer of a moisture pervious matrix having a desiccant therein on the base; moving a first sheet having a first major surface and an opposite second major surface into the spacer frame over and spaced from the matrix to move the first major surface of the first sheet against the first layer, and moving a second sheet having a first major surface and an opposite major surface toward the second layer to move the first major surface of the second sheet against the second layer, wherein the first surface of the second sheet is spaced from the second surface of the first sheet to provide a compartment therebetween and the desiccant is in communication with the compartment. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an orthogonal view of a prior art window sash having an insulating viewing area, with portions removed for purposes of clarity. 
       FIG. 2  is a front elevated view of an integrated window sash unit incorporating features of the invention. 
       FIGS. 3 and 3A  are views taken along lines  3 - 3  of  FIG. 2 . 
       FIG. 4  is a plan view of an arrangement of sash members during fabrication of the sash incorporating features of the invention. 
       FIG. 5  is a side view of a continuous sash member lineal having mitered end and notched cutout sections. 
       FIG. 6  is a partial plan view of an arrangement to heat ends of sash members to join the ends to make a sash frame. 
       FIG. 7  is a partial plan view and an exposed view illustrating a technique for sealing corners of a closed sash frame. 
       FIG. 8  is sectional views A through K of a sash member incorporating different embodiments of a retainer clip of the present invention. 
       FIG. 9  is sectional views A through J of alternate desiccant reservoir configurations. 
       FIG. 10  is side views A through H of alternate vent hole configurations. 
       FIG. 11  is a view similar to  FIG. 3  illustrating a glazing unit incorporating three glass plies. 
       FIG. 12  is a view similar to  FIG. 2  illustrating an integrated window sash unit incorporating muntin bars. 
       FIG. 13  is a view taken along lines  13 - 13  of  FIG. 12 . 
       FIG. 14  is a perspective view of one non-limiting embodiment of a muntin clip of the present invention. 
       FIG. 15  is a plan view of another non-limiting embodiment of a muntin clip of the present invention, with portions removed for purposes of clarity. 
       FIG. 16  is a plan view of still another non-limiting embodiment of a muntin clip of the present invention, with portions removed for purposes of clarity. 
       FIG. 17  is a side view of another non-limiting embodiment of a muntin clip of the present invention, with portions removed for purposes of clarity. 
       FIG. 18  is a cross-sectional view of a sash frame illustrating multiple nozzles for extruding sealant and desiccant on the sash frame. 
   

   DESCRIPTION OF THE INVENTION 
   As used herein, spatial or directional terms, such as “inner”, “outer”, “left”, “right”, “up”, “down”, “horizontal”, “vertical”, and the like, relate to the invention as it is shown in the drawing figures. However, it is to be understood that the invention can assume various alternative orientations and, accordingly, such terms are not to be considered as limiting. Further, all numbers expressing dimensions, physical characteristics, and so forth, used in the specification and claims are to be understood as being modified in all instances by the term “about”. Accordingly, unless indicated to the contrary, the numerical values set forth in the following specification and claims can vary depending upon the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Moreover, all ranges disclosed herein are to be understood to encompass any and all subranges subsumed therein. For example, a stated range of “1 to 10” should be considered to include any and all subranges between (and inclusive of) the minimum value of 1 and the maximum value of 10; that is, all subranges beginning with a minimum value of 1 or more and ending with a maximum value of 10 or less, e.g., 1 to 6.7, or 3.2 to 8.1, or 5.5 to 10. Also, as used herein, the terms “deposited over”, “applied over”, or “provided over” mean deposited, applied, or provided on but not necessarily in surface contact with. For example, a material “deposited over” a substrate does not preclude the presence of one or more other materials of the same or different composition located between the deposited material and the substrate. 
   Before discussing several non-limiting embodiments of the invention, it is understood that the invention is not limited in its application to the details of the particular non-limiting embodiments shown and discussed herein since the invention is capable of other embodiments. Further the terminology used herein to discuss the invention is for the purpose of description and is not of limitation. Still further, in the following discussion, unless indicated otherwise, like numbers refer to like elements. 
   Non-limiting embodiments of the invention will be discussed to fabricate a sash having two or more sheets in the enclosed open area defined by the sash frame. In the following discussion of the non-limiting embodiments of the invention, the sheets are glass sheets to make a window sash having an insulating viewing area; however, as will become apparent, the sheets can be made of any material, e.g. glass, plastic, metal and/or wood, and the selection of the material of the sheets is not limiting to the invention. Still further, the sheets can be made of the same material or the sheets may be made of different materials. In addition, one or more sheets can be monolithic sheets, and the other sheet(s) can be laminated sheet(s), e.g. made of one or more monolithic sheets laminated together in any usual manner. Although the discussion of the invention is directed to window sash, the invention is not limited thereto and the invention can be practiced to provide one or more windows having one or more sheets in a door window opening, e.g. but not limited thereto, a window opening in a front door or a patio door. 
   In the practice of the non-limiting embodiments of the invention, one or more of the glass sheets can be uncoated and/or coated colored and/or clear sheets; the colored sheets can be of the type disclosed in U.S. Pat. Nos. 4,873,206; 4,792,536; 5,030,593 and 5,240,886, which disclosures are hereby incorporated by reference, and one or more of the surfaces of one or of the more sheets can have an environmental coating to selectively pass predetermined wavelength ranges of light and energy, e.g. glass or plastic transparent sheets can have an opaque coating of the type used in making spandrels or coatings of the type disclosed in U.S. Pat. Nos. 4,170,460; 4,239,816; 4,462,884; 4,610,711; 4,692,389; 4,719,127; 4,806,220; 4,853,256 and 4,898,789, which disclosures are hereby incorporated by reference. Still further, in the practice of the non-limiting embodiments of the invention, the surfaces of the sheets can have a photocatalytic film or water reducing film, e.g. of the type disclosed in U.S. Pat. No. 5,873,203; U.S. Pat. No. 6,027,766; and U.S. Pat. No. 6,027,766, which disclosures are hereby incorporated by reference. It is contemplated that the photocatalytic film disclosed in U.S. Pat. No. 6,027,766 and U.S. Pat. No. 6,027,766 and/or the water reducing film disclosed in U.S. Pat. No. 5,873,203 can be deposited on the outer surface and/or the inner surface of one or more of the sheets of the window sash, as well as on the surface of the sash frame. 
   Prior to describing non-limiting embodiments of the invention, a discussion of a window sash having an insulating glazed unit is presented for an appreciation of the function and cooperation of the elements of the glazed unit and of the sash frame that are eliminated, combined, or modified to provide the window sash of the invention having the sheets spaced from one another by the sash frame, and optionally the space or compartment between the sheets sealed against moisture penetration and/or gas egress from the compartment. With reference to  FIG. 1 , there is shown a window sash  30  of the prior art having an insulating unit  32  mounted in a sash frame  34 . The unit  32  includes a pair of glass sheets  36  and  38  spaced from one another by a spacer frame  40  and secured to outer surface of legs  42  and  44 , respectively, of the spacer frame  40  by a layer  46  of an adhesive sealant to provide a space or sealed compartment  48  between the sheets  36  and  38 . The layers  46  have a low vapor transmission or permeability and the surface of the spacer frame  40  facing the compartment  48  is gas and moisture impervious or resistant. The adhesive layers  46  and the spacer frame  40  prevent moisture from freely moving into the compartment  48  between the sheets  36  and  38 . In the instance when an insulating gas, e.g. argon or krypton, is in the compartment, the layers  46  and the surface of the spacer frame  40  facing the compartment are each impervious or resistant to passage of the insulating gas to prevent egress of the insulating gas from the compartment  48 . 
   A moisture pervious matrix  50  having a desiccant (not shown) is on the inner surface of the spacer frame  40  and communicates with the compartment  48  to absorb or adsorb moisture and selectively absorb or adsorb free volatile organic molecules in the compartment. As can be appreciated, the insulating unit  32  can have more than two sheets. For a more detailed discussion of insulating units, reference can be had to U.S. Pat. Nos. 5,177,916; 5,531,047; 5,553,440; 5,564,631; 5,617,699; 5,644,894; 5,655,282; 5,720,836; 6,115,989; 6,250,026 and 6,289,641. 
   The sash frame  34  usually includes four sash members (only three sash members  52 ,  53  and  54  shown in  FIG. 1 ) having their ends  56  joined together in any convenient manner to form the sash frame  34  for receiving the insulating unit  32 . The sash members each include a ridge or stop ledge  58  that engages marginal edge portions of side  60  the insulating unit  32  to maintain the unit in the sash frame  34 . Glazing clips (not shown) engage the sash frame and the marginal edges of the other side of the insulating unit i.e. side  62  to secure the insulating unit in the sash frame. Glazing sealant  64  is provided around the marginal edge portions of the side  62  of the insulating unit  32  and adjacent portions of the sash frame  34  to prevent water from moving between the unit and the sash and for aesthetics. 
   The non-limiting embodiments of the invention eliminate, among other things, the spacer frame  40  that (1) functions to space the glass sheets and co-operates with the adhesive layers  46  to provide the sealed compartment  48  of the insulating unit  32 , and (2) functions to provide a surface to carry the desiccant containing matrix  50 . More particularly, the non-limiting embodiments of the invention discussed herein provide a sash frame that has, and/or sash members that have, among other things, the function and cooperation of the eliminated spacer frame of the glazing unit. 
   With reference to  FIGS. 2 and 3 , there is shown an integrated window sash  80  having a thermally insulating viewing or vision area  82  incorporating features of the invention. The insulating vision area  82  of the window sash  80  includes a pair of sheets  84  and  86  held in spaced relation by sash frame  88  to provide the insulating viewing area  82 . As can be appreciated, the peripheral shape of the sash frame  88  and the viewing area  82  is not limiting to the invention; however, for ease of discussion, but not limiting to the invention, the peripheral shape of the sash frame  88  and the viewing area  82  is shown to have a parallelepiped shape, e.g. a rectangular shape as shown in  FIG. 2 ; however, as will become apparent from the following discussion, the invention is not limited thereto and the sash frame  88  and/or the viewing area  82  can have any peripheral shape, e.g. trapezoidal, circular, elliptical, polygon having three or more sides, a combination of linear and circular portions, a combination of linear and elliptical portions or any combinations thereof. 
   The sash frame  88  shown in  FIG. 2  has adjacent ends  90  of the sash members or segments  92 - 95  joined together in any convenient manner; however, unless indicated otherwise in the following discussion of the sash frame  88 , the ends  90  of the sash members  92 ,  93 ,  94  and  95  can be joined together or can be in contact with one another but not joined together. Further in the following discussion of the sash members  92 - 95 , unless indicated otherwise, the ends of the sash members can be joined together, can be in contact with one another but not joined together or can be spaced from one another as shown in  FIG. 4 . 
   With reference to  FIG. 3 , the discussion is directed to the sash member  92 , however, the discussion unless indicated otherwise is similarly applicable to sash members  93 - 95 . The sash member  92  of sash frame  88  in cross section as viewed in  FIG. 3  has a step-like configuration formed by walls  98  and  100  spaced apart and interconnected by base  102 , and the wall  100  and outer surface  104  of the sash member  92  spaced from one another and interconnected by grooved ledge  106  discussed in detail below. The perimeter of the base  102 , the perimeter of edge  108  of the wall  98 , and the perimeter of the sheet  84  are sized such that with the sash frame  88  formed, the sheet  84  can be moved over the base  102  into engagement with the wall  98 . The wall  98  retains the sheet  84  in the viewing area  82  of the sash frame  88 . The perimeter of the base  102 , the perimeter of the ledge  106  and the perimeter of the sheet  86  are sized such that with the sash frame  88  formed, the marginal edges of the sheet  86  engages the wall  100 . The wall  100  prevents the sheet  86  from moving over the base  102  and spaces the sheets  84  and  86  apart to provide a space or compartment  110  between the sheets. The walls  98  and  100 , and the base  102  of the sash members provide the sheet spacing function of the spacer frame  40  shown in  FIG. 1 . 
   A layer  114  of a sealant-adhesive between surface  116  of wall  98  and marginal edge portions of outer surface  118  of the sheet  84  secures the sheet  84  in place. Similarly, a layer  120  of a sealant-adhesive between surface  122  of the wall  100  and marginal edge portions of inner surface  124  secures the sheet  86  in place. Although not required and not limiting to the invention, the surfaces  116  and  122  of walls  98  and  100 , respectively, can be provided with one or more slots or grooves that function as sealant reservoirs and spacers. More particularly and with referring to  FIG. 3  and without limiting the present invention, the surface  116  of wall  98  has the edge  108  extending beyond the surface  116  to provide a groove  128 , and the surface  122  of the wall can have a pair of spaced ribs  130  shown in phantom to provide three spaced grooves  132 . The layer  114  of the sealant adhesive is applied to the surface  116  of the wall  98  to fill the groove  128 , and the layer  120  of the sealant adhesive is applied to the surface  120  of the wall  100  to fill the grooves  132 . 
   The sheets  84  and  86  are moved against their respective walls  98  and  100  against the layers  114  and  120  in the grooves  128  and  132 , respectively, to provide a layer of sealant adhesive having a predetermined thickness between the sheets and their respective surfaces. In other words, the edge  108  extends beyond the surface  116  of the wall  98 , and the ribs  130  extend beyond the surface  122  of the wall  100  to provide a layer of adhesive sealant in its respective groove having a predetermined depth and width to allow for biasing the sheets against their respective wall, as is discussed in more detail below, while eliminating excessive thinning of the sealant adhesive layers. 
   The function and cooperation of the spacer frame  34 , the layers  46  and the glass sheets  36  and  38  to provide the sealed compartment  48  of the insulating glazing unit  32  shown in  FIG. 1  is provided by the function and cooperation of the layers  114  and  120  of the sealant adhesive, the walls  98  and  100 , and the base  102  of the sash segments  92 - 95  making up the sash frame  88 , and the glass sheets  84  and  86  to provide the sealed compartment  110 . 
   As can be appreciated, the invention contemplates an unsealed compartment between the sheets, i.e. a compartment in which fluid, e.g. but not limiting thereto, gas and/or vapor, e.g. moisture can move with minimal resistance into and out of the compartment  110 . In this instance, the sash member can be made of any structurally sound material, e.g. the sash members maintain their shape, and are not limited to the gas and moisture resistance, i.e. moisture vapor permeability, of the material. In the preferred practice of the invention, the compartment  110  is a sealed compartment, i.e. a compartment in which movement of gas and/or moisture into and out of the compartment  110  is restricted. In the instance when the compartment  110  is a sealed compartment, the sash members can be made of any structurally sound material, and at least the surface of the base  102  of the sash members of sash frame facing the compartment  110 , and the layers  114  and  120  of the sealant adhesive, are moisture resistant, i.e. have a low moisture vapor permeability, to prevent or retard the movement of moisture into the compartment  110  and/or gas impervious or resistant to prevent insulating gas, e.g. argon or krypton, from moving out of the compartment  110 . 
   Materials that can be used in the practice of the invention to make the sash members includes, but are not limited to metal, wood, plastic, composite materials, fiber reinforced plastics and combinations thereof. Metals, e.g. but not limited to stainless steel and aluminum, are easily formed, and are moisture and gas impervious or resistant. As is appreciated by those skilled in the art, metals conduct heat from the home interior during winter and into the home interior during summer. When metal is used to fabricate the sash member, it is preferred to provide the metal sash member with a thermal break of the types usually used in the art to reduce if not eliminate the heat loss through the sash member. Wood, like metal, is easily shaped into the desired cross sectional configuration, and unlike metal is a low conductor of heat and has a high permeability to gas and moisture. The high permeability of wood permits moisture and gas to move through the wood into and/or out of the compartment between the sheets. As can be appreciated by those skilled in the art, low gas permeation rate is important to maintaining gas conditions between the glass sheets, especially if the compartment between the sheets is filled with argon or krypton. Low moisture vapor transmission rate is desirable because low moisture content or dew point of the between-sheets gas atmosphere is especially important to maintaining clear visibility through the vision area. One technique to reduce or prevent moisture moving through the wood into or out of the compartment is to provide a moisture impervious and/or resistant barrier or seal of the type discussed below. Plastic, like wood and metal, is easy to shape, and like metal can be shaped by pultrusion or extrusion. Unlike metal and like wood, plastic is a low conductor of heat; some plastics like wood have high permeability to moisture and/or gas, and some plastics unlike wood but like metals have low permeability to moisture and/or gas. 
   From the forgoing, it can be appreciated that in the preferred practice of the invention, the sash member is made of plastic. Types of plastic that can be used in the practice of the invention to form the sash members include but are not limited to polyvinyl chloride (PVC), acrylonitrile-butadiene-styrene (ABS), cellular PVC, polypropylene and fiber reinforced plastics. Further, as can be appreciated, the invention is not limited to any particular cross-sectional configuration of the sash members. For example, the sash members  92 - 95  can be solid or include hollow portions  134  as shown in  FIG. 3 . In one non-limiting embodiment of the invention, the hollow portions  134  can be filled with insulating material (not shown) for reduced heat transfer. 
   In the instance where the material of the sash member has a high gas and/or moisture vapor permeability, e.g. wood or certain plastics, a barrier layer  140  (see  FIG. 3 ) of a material having a low gas and moisture is vapor permeability, e.g. polyvinylidene chloride (PVDC) or metal, e.g. aluminum or stainless steel, can be applied at least over surface portions of the base  102  of the sash members facing the compartment  110 . Preferably, the barrier layer  140  completely covers the base  102  and extends over a portion of the surface  116  of the wall  98  and over a portion of the surface  122  of the wall  100 . In this manner, an edge portion of the barrier layer  140  extends under the peripheral edges and over a portion of the marginal edges of the outer surface  118  of the sheet  84  and the opposite edge portion of the barrier layer is spaced from marginal edge portions of the inner surface  124  of the sheet  86 . 
   As can now be appreciated, the invention contemplates applying the barrier layer  140  to all the exposed surfaces, or to selected surface portions, of the sash member, e.g. applying a barrier layer to the surfaces of the hollow sections of the sash members, especially surface portions of the hollow section opposite the base  102 . The barrier layer can be applied to the sash members before or after they are joined together to form the sash frame using any applying technique, e.g. but not limited to, spraying-on, rolling on, curtain or flow coating on, brushing on a coating layer that forms the barrier layer, hot-melt extrusion of a barrier layer, cap stock and/or composite extrusion of a sash member having a barrier layer, extruding sash members with barrier inserts, e.g. but not limited to a metal strip within the plastic extrusion, gun applying a barrier layer through a shaped orifice, shrink wrapping a barrier layer film on the sash member, roll pressing a single or multi-layer tapes, e.g., but not limited to VentureClad™ 1577CW® tape available from Venture Tape Corp., Massachusetts, press rolling a pre-extruded thick tape, e.g. polyisobutylene tape having a thickness of at least 0.016 inches, applying multi layer materials to the sash member, e.g. but not limited to applying a foil then applying a polymer overcoat, applying a multi layer 2-part materials, e.g. but not limited to applying a base material then applying a catalyst material, and applying a barrier surface by surface fusion and/or infusion of nano-barrier materials such as nano-particles. In addition, the invention contemplates preparing the surface of the sash member by secondary processes as known by those skilled in the art, e.g. but not limited to, corona surface treatment of polyvinyl chloride to enhance adhesion of the barrier layer, applying a physical vapor deposition of inorganic barrier material, e.g. aluminum oxide, silicon oxide and mixtures of multi-layers thereof, ultraviolet cure mechanisms, e.g. but not limited to ultraviolet cure of organo-metallic barrier layers and ultrasonic cure mechanisms to further enhance barrier layer properties. As an alternative and/or in addition to using a barrier layer to reduce the moisture vapor transmission rate performance and gas permeation performance of the sash, the thickness of selected critical web portions of the sash members can be increased, e.g. but not limited to the base  102  of the sash members. 
   As can be appreciated the invention is not limited to the material of the barrier layer. For example, the barrier layer can be made of any material that has a low moisture vapor permeability, i.e. less than 0.1 grams per square meter per day (hereinafter “gm/M 2 /day”, for example less than 0.05 gm/M 2 /day) as determined by using the procedure of ASTM F 372-73, and more particularly, in the range of 0.01-0.10 gm/M 2 /day, preferably in the range of 0.02-0.05 gm/M 2 /day, and more preferably in the range of 0.025-0.035 gm/M 2 /day. As can be appreciated for metal barrier layers the permeability is 0 gm/M 2 /day. In the instance when the compartment contains an insulating gas, e.g. but not limited to argon, the barrier layer should have a low gas permeability, e.g. less than 5%/yr and for argon preferably 1%/yr, as measured using European procedure identified as DIN 52293. Barrier films can be made from, but not limited to, films made of metal, crystalline polymeric material including, but not limited to polyvinylidene chloride, polyvinyl alcohol, ethylene vinyl alcohol, polyacrylonitrile, polyethylene naphthalate, oriented polypropylene, liquid crystal polymer, oriented terephthalate, polychloro-fluoro-ethylene, polyamide 6, polyvinylidene fluoride, polyvinyl chloride or polytrichlorofluoro ethylene and copolymers thereof, and other plastic materials meeting the above requirements. More particularly, barrier films can be made from, but not limited to films made of metal and polymeric materials including, but not limited to: thermoplastics such as acetal resins (polyoxymethylene), acrylic resins (acrylonitrile-methyl acrylate copolymer), cellulosic plastic, fluoroplastics (fluoropolymer, ethylene-chlorotrifluoroethylene copolymer (ECTFE), ethylene-tetrafluoroethylene copolymer (ETFE), fluorinated ethylene-propylene copolymer (FEP), perfluoroalkoxy resin (PFA &amp; MFA), polychlorotrifluoroethylene (PCTFE), polytetrafluoroethylene (PTFE), polyvinyl fluoride (PVF), polyvinylidene gluoride (PVDF), hexafluoropropylene, tetrafluoroethylene, ethylene (HTE), tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, terpolymer (THV)), ionomers, parylenes, polyamides (Amorphous Nylon, Nylon 6-PA6, Nylon 66-PA 66, Nylon 6/66-PA 6/66, Nylon 6/12-PA 6/12, Nylon 6/6.9-PA 6/69, Nylon 6.6/6.10-PA 66/610), polyamide nanocomposites, polycarbonates, polyesters (polybutylene terephthalate (PBT), polyethylene napthalate (PEN), polycyclohexylenedimethylene terephthalate (PCTG), polycyclohexylenedimethylene ethylene terephthalate (PETG), polyethylene terephthalate (PET), liquid crystal polymer (LCP)), polyimides, polyolefins (Ultra low density polyethylene (ULDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), medium density polyethylene and linear medium density, polyethylene (MDPE &amp; LMDPE), high density polyethylene (HDPE), polyolefin plastomers (POP), cyclic olefin copolymer (COC), ethylene-vinyl acetate copolymer (EVA), ethylene-acrylic acid copolymer (EAA), polypropylene (PP), polybutene, polybutylene (PB)), polyphenylene sulfides, polysulfones, polyvinyl alcohol, styrenic resins (acrylonitrile-butadiene-styrene copolymer (ABS), acrylonitrile-styrene-acrylate copolymer (ASA), polystyrene (PS), oriented polystyrene (OPS), general purpose polystyrene (GPPS), high impact polystyrene (HIPS), styrene-acrylonitrile copolymer (SAN), ethylene-vinyl alcohol copolymer (EVOH), styrene-butadiene block copolymer (SBS)), and vinyl resins (polyvinylidene chloride (PVDC), polyvinylidene chloride coated films (PVDC) coated polyester films); thermosets such as epoxy resins; thermoplastic elastomers such as olefinic thermoplastics elastomers, polyether block amides, polybutadiene thermoplastic elastomer, polyester thermoplastic elastomer, styrenic thermoplastic elastomer, and vinyl thermoplastic elastomers, and rubbers such as butadiene rubber, butyl rubber, bromobutyl rubber, chlorobutyl rubber, polyisobutylene rubber, chlorosulfonated polyethylene rubber, epichlorohydrin rubber, ethylene-propylene rubber, fluoroelastomer (vinylidene fluoride-hexafluoropropylene copolymer), natural rubber, neoprene rubber, nitrile rubber, polysulfide rubber, polyurethane rubber, silicone rubber, styrene-butadiene rubber. The invention is not limited to the thickness of the barrier film, however the film should be sufficiently thick to provide the desired resistance to movement of moisture and/or gas through the film. For example, but not limited thereto, a 0.001 inch (0.00254 centimeter) thick aluminum film or a polyvinylidene chloride film in the thickness range of 0.005-0.60 inches, preferably in the range of 0.010-0.040 inches, and more preferably in the range of 0.020-0.030 inches meets the requirements discussed above. 
   The instant invention also contemplates having a sash member whose body is made entirely from a polymeric material having a low moisture vapor permeability such as, but not limited to, the crystalline polymeric material and/or from making the sash member by modifying the material used to make the sash members to improve its moisture and/or gas permeation performance. In one non-limiting embodiment of the invention, the mixtures include but are not limited to blending liquid crystal polymers with PVC and nano-meter scale platelets, e.g. but not limited to, aluminum silica platelets. 
   As can be appreciated by those skilled in the art, the surface portion of the sash frame and the moisture impervious or resistant adhesive sealant of the layers  114  and  120  should be compatible, i.e. the adhesive must adhere to and not chemically react with the sash frame and barrier layer. In one non-limiting embodiment, the sash member is PVC and a crystalline polymeric material barrier layer or a metal barrier layer is applied completely over the surface of the base  102  and extending about 0.125 to 0.25 inches onto the surface  114  of the wall  98  and onto the surface  122  of the wall  100 . Optionally, the metal barrier layer can extend further over, or completely cover the surface  114  of the wall  98  and/or the surface  122  of the wall  100 . 
   In the following discussion and not limiting to the invention, the invention is discussed using a barrier layer made of crystalline polymeric material. As is appreciated by those skilled in the art, crystalline polymeric materials have a lower thermal conductivity than metals, e.g. aluminum or stainless steel and therefore are preferred, but not limited to the practice of the invention. 
   As can be appreciated by those skilled in the art, crystalline polymeric materials do not readily adhere to PVC surfaces and therefore an adhesive layer is used to adhere the layer of crystalline polymeric material to selected surfaces of the PVC sash members or the PVC sash frame. The adhesive layer may consist of any one of a number of adhesives such as, but not limited to, ethyl vinyl acetate. In one non-limiting embodiment, molten ethyl vinyl acetate resin and a molten crystalline polymer resin, e.g. but not limited to the invention polyvinylidene chloride resin, are extruded in any convenient manner to provide a molten barrier layer and thereafter PVC molten resin and the barrier layer are co-extruded to provide a sash lineal having a PVC body with at least the base  102  covered with the barrier layer. It is well recognized that crystalline polymeric materials can deteriorate as a result of exposure to ultraviolet radiation. Therefore, the surface of the barrier layer should be protected against ultraviolet radiation. 
   In a non-limiting embodiment of the invention, barrier layers made of plastic that deteriorate when exposed to ultraviolet radiation, e.g. but not limited to the crystalline polymeric barrier layer, can be protected by providing the sheets facing the sun, e.g. the sheet  86  with an ultraviolet coating or a glass sheet that absorbs ultraviolet radiation, e.g. a glass with cerium or titanium as taught in U.S. Pat. Nos. 5,240,886 and 5,593,929, which patents are hereby incorporated by reference. In another non-limiting embodiment of the invention, an adhesive film, e.g. ethyl vinyl acetate is applied on each of the major surfaces of the crystalline polymeric material. For example but not limited to the invention, crystalline polymeric resin, e.g. polyvinylidene chloride is fed into the center orifice of an extruder and molten ethyl vinyl acetate resin fed into orifice of the extruder on each side of the center orifice to extrude a barrier layer having a polyvinylidene chloride layer between and adhered to a pair of ethyl vinyl acetate layers, e.g. as disclosed in Japanese Patent Application JP 1-128820, which application is hereby incorporated by reference. The three layer tape and molten PVC resin are extruded together to provide a sash lineal having the three layer barrier layer on at least the base  102  of the sash member or the sash frame. In another non-limiting embodiment of the invention, the surface of the crystalline polymeric material of the barrier layer is covered with a desiccating medium as discussed below. In a still further non-limiting embodiment of the invention, the solar control glass, the three layer barrier layer and the desiccating medium are all used together. 
   In the preferred practice of the invention, but not limited thereto, and it is preferred to simultaneously extrude a three layer barrier layer (a polyvinylidene chloride layer  144  between and adhered to a pair of ethyl vinyl acetate layers  145  and  146 , see  FIG. 3A ) on a PVC lineal such that the barrier layer covers the base and selected portions of the surfaces  114  and  122  of the walls  98  and  100 , respectively, as discussed above. The thickness of the adhesion layer  146  is not limiting to the invention but should be sufficiently thick to secure the barrier layer  140  to the selected surface portions of the sash member and the adhesion layer  145  should be sufficiently thick to provide ultraviolet protection to the polyvinylidene chloride layer, e.g. thicknesses in the range of greater than 0 and less than 0.003 inches are acceptable, with a thickness of up to 0.002 inches preferred and a thickness range of 0.0005 to 0.001 inches most preferred. The dimensions of the sash member are not limiting to the invention, however the dimensions should be sufficient to provide a sash member that is structurally stable and sized for the intended use of the sash member, e.g. to make a sash frame of predetermined dimensions. 
   The adjacent ends  90  of the sash members  92 - 95  can be joined in any manner to provide a sash frame  88  having corners sealed against moisture penetration when the window sash  80  is to have a sealed compartment  110 . In the instance when the window sash  80  is to have an unsealed compartment  110 , the corners of the sash frame do not have to be sealed. With reference to  FIGS. 3 and 4 , as required, the sash members  92 - 95  have mitered ends  90  and the general cross section of the sash members is as shown in  FIG. 3 . The mitered ends  90  of adjacent sash members  92 - 93 ,  93 - 94 ,  94 - 95  and  95 - 92  are moved into contact with one another and held together in any usual manner, e.g. by nails, screws, adhesive, fusion welding, vibration welding, etc. 
   As an alternative to assembling the sash frame  80  from a plurality of discreet sash members  92 - 95 , the sash frame  80  can be made from a single lineal cut from a piece of extrusion, e.g. but not limiting to the invention, a PVC extrusion. More specifically, shown in  FIG. 5  is a lineal  150  of sash material cut to the length of the sash frame periphery. A cut is made at both ends  152  and  154  of the lineal  150  and intermediate notched cutouts  156  (only one shown in  FIG. 5 ) are made at locations between the ends  152  and  154  depending on the configuration of the sash frame. For example, if the sash frame includes “X” number of sides, and therefore there are “X” corners, the lineal  150  will have “X−1” notched cutouts  156 . The intermediate cutouts  156  are made so as to not cut through the back web  160  (see also  FIG. 3 ) of the lineal  150 , so as to leave an uncut piece of extruded sash around the entire unit, with the exception of the closure corner. In this manner, the web is continuous at and around each of the corners where the lineals is notched. The use of multiple notched cutouts along the length of the lineal  150 , is not limiting to the invention and the number can be of whatever number is needed to form the desired shape of the sash frame. The angles of the cutouts  156  along the length and the end  152  and  154  of the lineal  150  are adjusted to fit the desired angles at the corners of the sash frame. The lineal  150  is then folded at the cutouts  156 , and the ends  152  and  154  and the intermediate cut outs  156  are joined, for example by welding, bonding, adhering, or external fastening. It should be appreciated that viewing the assembled sash frame would indicate continuous web and the previous separation of the other components of the lineal due to the notched cutouts. 
   To form a square or rectangle, a cut is made at both ends  152  and  154  of the lineal  150  such that surface  162  of the end  152  and surface  164  of the end  154  are at an angle A of approximately 40 to 45 degrees to an imaginary line  166  normal to the plane of the back web  160 , and three intermediate notched cutouts  156  (only one shown in  FIG. 5 ) made at locations between the ends  152  and  154  with sides  168  of the cutouts forming an angle B of approximately 80 to 90 degrees. In another non-limiting embodiment of the invention, the sash frame  88  is square or rectangular, surface  162  of the end  152  and surface  164  of the end  154  each subtend an angle A in the range from 40 to 43 degrees, and the surfaces  168  of the three intermediate cutouts  156  (only one shown in  FIG. 5 ) form an angle B in the range from 80 to 85 degrees, to make certain that extra material, if needed in the welding process, will be available at each joint formed by the meeting of the surfaces  162  and  164  of the ends  152  and  154 , respectively, and the surfaces  168  of the cutouts  156  to ensure that the interior of the sash frame  88  is properly sealed. Additional advantages of not cutting through the back web  160  of the sash lineal  150  is that the alignment of adjacent corners during the corner bonding process is maintained, and the sash frame is faster to fabricate than traditional fabrication using individual sash members. 
   It should also be appreciated that the surfaces  162  and  164  of the ends  152  and  154 , respectively, and the surfaces  168  of the cutouts  156  are not limited to a straight edge as shown in  FIG. 5 . More particularly, in one non-limiting embodiment of the invention, these surfaces are shaped, for example scalloped (imaginary line  169 ) or step (imaginary line  170 ) as shown in phantom in  FIG. 5 , to complement each other so that as the lineal  150  is bent the surfaces  162  and  164  of the ends  152  and  154 , respectively, and the surfaces  168  of the cutouts  156 , move into contact with one another, fit together and enmesh to construct the completed sash frame  88 . 
   Although not limiting to the invention, during the sash frame assembly and welding operation, in addition to or in place of the extra material provided at the welded joints as discussed above, an additional piece of weldable material (not shown) can be inserted between the opposing surfaces  162  and  164  of the ends  152  and  154 , respectively, and the surfaces  168  of the cutouts, as the sash frame is formed and the joints are welded. The additional piece provides additional material at the joints to further seal the joints of the sash frame and ensures airtight welded joints. Although not limiting to the invention, the additional piece can be a flat piece of stock made from the same material as the extruded lineal. 
   The invention is not limited to the process for joining the ends  90  of adjacent sash member  92 - 95 , and any convenient process that provides sealed joints can be practiced. With reference to  FIG. 6  and not limiting to the invention, a heatable plate  170  is positioned between the ends  90  of adjacent sash members  92 - 95 , e.g. ends  90  of sash members  92  and  95  as shown in  FIG. 6 . The heatable plate  170  is heated and after the melting temperature of the ends  90  of the sash members  92  and  95  is reached and the ends of the adjacent sash members starts to soften, the plate  170  is removed, and the ends of the adjacent sash members are moved together to join the ends. When the barrier layer is plastic, ends of adjacent sash members are moved together, to join the sash members including the plastic barrier layer. Optionally, the ends of adjacent sash members can be moved together and moved along a reciprocating path designed by the arrows  172  and  174  (see  FIG. 6 ). Excess plastic flows out from the surfaces to the sash member. After the sash frame is formed, excess melted plastic is removed in any convenient manner, e.g. but not limiting thereto by air abrasion from all surfaces except for the joined ends of the barrier layer. With reference to  FIG. 7 , another non-limiting embodiment of the invention to seal the corner is to provide the barrier layer on the base as previously discussed and to mill a recess  176  in surface  178  of each end  90  of each one of the sash members  92 - 95  (only ends  90  of the sash members  92  and  93  shown in  FIG. 7 ). A layer  180  of a material having a low vapor and gas permeability, e.g. a polyisobutylene tape or any of the adhesive-sealants discussed above, is placed in the recess  176 . As the ends of the mitered sash members are brought together, the layers  180  are urged together to form a moisture and/or gas impervious seal around the peripheral and marginal edges of the sheets. It should be appreciated that this technique can be use in any type of assembly method, for example but not limited to those assembly methods discussed above. The invention further contemplates providing strips of moisture impervious or resistant thermoset or thermoplastic adhesive sealant between the ends  90  of adjacent sash members, and heating the adhesive sealant in any convenient manner to flow the adhesive sealant and seal the joining ends of the sash members. 
   In another embodiment of the invention, the ends of adjacent sash members are joined together in any convenient manner, e.g. but not limiting to the invention, by screws or adhesives, and a patch of a low moisture and gas permeability tape or tapes is applied to and pressed onto the barrier layer  140  on the base  102  and overlapping the corners of the sash frame. The tape can be a film of the barrier layer  140  (see  FIG. 3 ) applied to the base, or can be a film of a material having a low moisture permeability bonded to a film of a material having low gas permeability. The adhesive for bonding the tape to the base can be the same type used to adhere the barrier layer to the PVC, e.g. ethyl vinyl acetate. 
   With reference to  FIGS. 1 ,  2  and  3  as needed, the sash frame  88  having the sealed corners, the barrier layer  140  on the base  102  and portions of the surfaces  116  and  122  of the walls  98  and  100 , respectively, replaces the spacer frame  34  of the glazing unit  32  shown in  FIG. 1 , and provides the function of the spacer frame maintaining the glass sheets spaced from one another to provide a sealed compartment between the sheets. The surfaces  116  and  120  of the walls  98  and  100 , the glass sheets  84  and  86 , and the layers  114  and  120  of the sealant adhesive cooperates with one another to provide the sealed compartment  110 . 
   The layers  114  and  120  of the adhesive sealant used to secure the glass sheets  84  and  86  to the surfaces  116  and  122  of the walls  98  and  100  of the sash frame  88  or sash members  92 - 95  are a moisture and vapor resistant adhesive-sealant of the type used in the art of making insulating glazing units to prevent moisture from the environment or atmosphere from moving into the compartment between the sheets. Although not limiting to the invention, in one non-limiting embodiment of the invention, the material for the layers  114  and  120  of the adhesive-sealant can be made of any material that has a low moisture vapor permeability, i.e. less than 0.1 gm/M 2 /day, for example less than about 0.05 gm/M 2 /day, as determined by using the procedure of ASTM F 372-73, and more particularly, in the range of 0.01-0.10 gm/M 2 /day, preferably in the range of 0.02-0.05 gm/M 2 /day, and more preferably in the range of 0.025-0.035 gm/M 2 /day. In the instance when the compartment contains an insulating gas, e.g. but not limited to argon, the layers  114  and  120  should have a low gas permeability, e.g. less than 5%/yr, and for argon preferably 1%/yr measured using the European procedure identified as DIN 52293. Adhesive-sealants that can be used in the practice of the invention include, but are not limited to, butyls, silicones, polyurethane adhesives, polysulfides, and butyl hot melts. Further, the material of the adhesive-sealant is selected depending on the insulating gas in the compartment  110 , e.g. argon, air, krypton, etc. to maintain the insulating gas in compartment  110 . 
   The layers  114  and  120  of the adhesive sealant can be applied to the surfaces  116  and  122  of the walls  98  and  100  in any convenient manner, and can be applied to the sash members  92 - 95  or to the sash frame  88 . In the practice of the invention, the smaller glass sheet  84  is placed in the sash frame opening and pressed against the layer  114  of the adhesive sealant to flow the adhesive sealant and secure the glass sheet  84  to the wall  98  of the sash frame  88 . Thereafter, the larger glass  86  is placed against the layer  122  of the adhesive sealant and pressed against the layer  122  of the adhesive sealant to flow the adhesive sealant and secure the glass sheet  86  to the wall  100  of the sash frame  88 . The adhesive sealant can be applied only to the marginal edges of the sheets, to the peripheral edges of the sheets or to the marginal and peripheral edges of the sheets. In the practice of the invention, it is preferred to apply the layers of the adhesive sealant to the surfaces  116  and  122  of the walls  98  and  100 , portions of the base  102  adjacent the wall  98  and portions of the grooved ledge  106  such that the adhesive sealant is applied to the marginal edges of the outer surface  118  and peripheral edges  186  of the glass sheet  84 , and to the marginal edges of the inner surface  124  and the peripheral edges  188  of the glass sheet  86  as shown in  FIG. 3 . In this manner, the peripheral edge  186  of sheet  84  can be supported and maintained in spaced relationship from base  102  and the peripheral edge  188  of sheet  86  can be supported and maintained in spaced relationship from the portion of the grooved ledge  106  as shown in  FIG. 3 . 
   As can be appreciated the glass sheets can be positioned within the sash frame in any convenient manner, for example, but not limiting thereto, the glass sheets can be positioned in the sash frame manually, or using automated equipment. For example but not limit the invention thereto, the sash frame can be mounted in a horizontal position, vertical position or angled position. A major surface of the glass sheet  84  is engaged by a sheet engaging device, e.g. but not limited to vacuum cups, and the sheet moved is against the layer  114  of the adhesive sealant to flow the adhesive sealant layer and seal the marginal edges of the sheet to the wall  98 . In the alternative, a roller (not shown) is moved over the marginal edges of the inner surface  198  of the sheet  84  to flow the layer  114  of the adhesive sealant. Thereafter, the sheet-engaging device engages a major surface of the glass sheet  86 , and moves the sheet  86  against the layer  120  of the adhesive sealant. The sheet is pressed against the layer  120  to flow the adhesive sealant and/or a roller (not shown) is rolled over the marginal edges of outer surface  190  to flow the adhesive sealant. The outer or inner major surface of the sheets  84  and  86  can be engaged, however, in the practiced of the invention, it is preferred to engage the outer major surface  118  of the sheet  84  and outer major surface  190  of the sheet  86  for ease of cleaning the sheet surfaces in the event the sheet engaging device mars the sheet surfaces. After the sheet  86  is in place, a holding component  192 , for example as shown in  FIG. 3 , is snapped or otherwise inserted into a groove or grooves  193  in the ledge  106  of the sash frame  88  and engages the marginal edge portions of the surface  190  of the sheet  86  to firmly hold and/or bias the sheet  86  against the layer  120  of the adhesive sealant. The holding component  192  can also be used to provide a balance to the widow sash by making the height of opposed sides of the window sash substantially equal. 
   As can be appreciated, the dimensions of the surfaces of the sash members  92 - 95  as viewed in cross section (see cross section of sash member  92  shown in  FIG. 3 ) and the length of the sash members are not limiting to the invention, and a general relationship is discussed for an appreciation of the invention. As viewed in  FIG. 3 , the height of walls  98  and  100  are generally in the range of 0.125 to 1.0 inches (0.32 to 2.54 centimeters (“cm”)). The width of the base  102 , i.e. the distance between surface  116  of wall  98  and surface  122  of wall  100 , depends on the desired spacing between sheets  84  and  86  and the sheet thickness. Without limiting the present invention, the glass sheet thickness in conventional insulating glass units typically ranges from 0.09 to 0.250 inches (2.2 to 6.35 millimeters (“mm”)). The distance between the glass sheets is not limiting to the invention; however, it is desirable that the distance be sufficient to provide an insulating gas space or compartment  110  between the sheets  84  and  86  while minimizing, if not eliminating, gas currents from forming in the compartment  110 . As is appreciated by those skilled in the art, the distance between the sheets  84  and  86  depends on the type of gas in the compartment  110 . Without limiting the present invention, the spacing between sheets  84  and  86  typically ranges from 0.25 to 1.0 inches (0.64 to 2.54 cm). For example, a distance in the range of 0.25 to 0.625 inches (0.63 to 1.58 cm) is typical for air. 
   As discussed above, the glass sheet  86  is biased against the layer  120  of adhesive sealant by the glass holding component  192 . As can be appreciated, the glass holding component  192  provides a mechanical biasing force against the outer marginal edges of the surface  190  of the glass sheet  86 . The glass sheet  84  as shown in  FIG. 3  relies on the adhesive strength of the layer  114  of the adhesive sealant to secure the glass sheet  84  in position. In an embodiment of the invention wherein sheet  84  is the outer sheet of the window sash, it is expected that the outer surface  118  of the glass sheet  84  will be exposed to the outside environment, and therefore, it is necessary to select an adhesive sealant having sufficient strength to withstand historical wind loads or pressures. As can be appreciated, the invention contemplates using a mechanical retaining device to bias the sheet  84  against the layer  114  of the adhesive sealant, or at least prevent the marginal edge of glass sheet  84  from separating from adhesive layer  114 . 
   Referring to  FIG. 8 , there is shown non-limiting embodiments of retaining devices or retainers to hold and/or bias the sheet  84  firmly against the layer  114  of the adhesive sealant applied to the wall  98 . As can be appreciated, the invention is not limited to the retainers shown in  FIG. 8 , which are shown for purposes of illustration and not for purposes of limitation. In  FIGS. 8A-8C , there is shown non-limiting embodiments of retainers of the invention that are integral with the sash members  92 - 95  (only sash member  92  shown in  FIGS. 8A-8C ), and in  FIG. 8D-8J  there is shown non-limiting embodiments of retainers of the invention that are detachably secured to the sash members after the sheet  84  is in position, and before the sheet  86  is put in position, as previously discussed. 
   Each embodiment of the retaining device or retainer shown in  FIG. 8A-8J  includes a flexible fin or finger having a sheet engaging portion that contacts at least inner surface  198  of the glass sheet  84  and biases the sheet  84  against the layer  114  of adhesive sealant on the wall  98 . With reference to  FIG. 8A , retainer  200  is a flexible finger or fin having a stepped end portion  202  to engage corner  204  of the sheet  84  and opposite end portion  206  of the retainer  200  is integral with body  208  of the sash members. Retainer  210  shown in  FIG. 8B  is a flexible fin or finger having a raised portion  212  that provides a stepped end portion  214  to engage the corner  204  of the sheet  84 . The opposite end  216  of the retainer  210  is integral with the body  208  of the sash member. Retainer  220  shown in  FIG. 8C  is a flexible finger or fin having end portion  222  biased against marginal edge portions of inner surface  198  of the sheet  84  and opposite end portion  226  integral with the body  208  of the sash members. The retainers  202 ,  210  and  220  of  FIGS. 8A ,  8 B and  8 C, respectively, are a continuous retainers that can be extruded along with the sash member. These retainers can be the same material as the remainder of the sash member or could be a separate, non-integral co-extruded material, for example with a different durometer than the sash member. In one non-limiting embodiment of the invention, the retainers have a lower durometer than the main body  208  of the sash member  92 - 95 . In the practice of the invention, as the sheet  84  is moved into the sash frame toward the wall  98 , the sheet  84  engages the retainer  200 ,  210  or  220  and biases it out of the path of the sheet  84 . After the sheet  84  is biased against the layer  114  of the adhesive sealant, the retainer  200 ,  210  or  220  moves to its initial position to bias the sheet toward the wall  98  against the layer  114 . 
     FIGS. 8D-8J  illustrate several similar retainer configurations that function the same as the retainers described above and shown in  FIGS. 8A-8C , but they are clip-type, non-continuous inserts that can be installed into the body  208  of the sash members  92 - 95  before or after the sheet  84  is in position against the layer  114  of the adhesive sealant. Each retainer shown in  FIGS. 8D-8J  can be continuously or intermittently applied. The portion of the clips that secures it to the body of the sash member can have a variety of attachment designs as shown in  FIGS. 8D-8J . More specifically, retainers  230 ,  232  and  234  shown in  FIGS. 8D-8F , respectively, are a “push-in” type clips having the non-glass-retaining portion of the retainer inserted into the body  208  of the sash member. Each of the retainers  230 ,  232  and  234  has an end portion  236  having an engaging member  238 . The engaging member  238  as shown in  FIGS. 8D-8F  is of the type commonly referred to as a “Christmas Tree” but can be any other type of interlocking devices. The engaging member  238  is commonly referred to as a “Christmas Tree” because the shape of the engaging member looks very much like a fir tree and in the industry is called a “tree” or “Christmas tree”. With reference to  FIG. 8D , the tree  238  is pushed into a groove  240  in the base  102 , between the walls  98  and  100 , of the sash members  92 - 95 . To securely hold the tree  238  in the groove  240 , the groove can be filled with an adhesive (not shown). In one non-limiting embodiment, the adhesive can be a moisture impervious adhesive having a desiccant, which is discussed in more detail below. End portion  250  of the retainer  230  shown in  FIG. 8D  is similar to the end portion  214  of the retainer  210  shown in  FIG. 8B ; end portion  252  of the retainer  232  shown in  FIG. 8E  is similar to the end portion  202  of the retainer  200  shown in  FIG. 8A , and end portion  254  of the retainer  234  shown in  FIG. 8F  is similar to the end portion  222  of the retainer  220  shown in  FIG. 8C . When the retainers of  FIG. 8D-8F  are set in position before the sheet  84  is in position, the engaging end portion  236  should be secured in the groove  240  to prevent the engaging end portion  236  of the retainers  230 ,  232  and  234  from moving out of the groove  240  as the sheet  84  moves over the retainer toward the wall  98 . 
   The retainers  260 ,  262  and  264  shown in  FIGS. 8G-81  are a “slide-in” type clips having non-glass-retaining end portion  266  of the retainer slid into a mating groove  268  in the sash members, e.g. see  FIG. 8G . Although not limiting to the invention, the groove  268  and the retaining end portion  266  are sized to capture the end portion  266  in the groove  268  when the retainers are set in the groove. In such a case, it is required to insert the retaining end portion  266  of the retainers  260 ,  262  and  264  in the groove  268  before the sash members are joined together. End portion  270  of the retainer  260  shown in  FIG. 8G  is similar to the end portion  214  of the retainer  210  shown in  FIG. 8B ; end portion  272  of the retainer  262  shown in  FIG. 8H  is similar to the end portion  202  of the retainer  200  shown in  FIG. 8A , and end portion  274  of the retainer  264  shown in  FIG. 8I  is similar to the end portion  222  of the retainer  220  shown in  FIG. 8C . 
   Retainer  280  shown in  FIG. 8J  has a flat-sided tab  282  extending from end portion  284  that is inserted into a flat-sided groove  286  in the body  208  of the sash member after the glass sheet  84  is in position. In the instance when the tab  282  is in the groove  286  before the sheet  84  is in position against the wall  98 , the tab  282  is retained in the groove by an interference fit. Sheet engaging end portion  288  of the retainer  280  is similar to the stepped end  202  of the retainer  200  shown in  FIG. 8A . The invention, however, is not limited thereto and the sheet engaging end portions  212  and  222  of the retainers  210  and  220  can be used by the retainer  280  shown in  FIG. 8J . 
   Retainer  290  shown in  FIG. 8K  includes an “L” shaped leg  291  having one leg  292  mounted to wall  98  and forms a groove  293  with the surface  116  of the wall  98  to receive the edge of the sheet  84 . The retainer  290  is flexible and is moved toward base  102  as the sheet  84  is positioned on the layer  114 . After the sheet is positioned on the layer  114  of the sealant adhesive the retainer  290  is released to its original position so that leg  292  moves over the marginal edges of the inner surface of the sheet  84 . Although not shown, the invention contemplates using a retainer  290  to engage the sheet  86  in a similar manner. 
   It can now be appreciated that in those non-limiting embodiments of the invention when the retainer is positioned on the body of the sash member before the sheet  84  is positioned on sash frame  88 , as the glass sheet  84  moves over the retainer toward the layer  114  of the adhesive sealant on the wall  98 , the retainers flex outwardly relative to the sash frame and springs back to its initial position after the sheet has passed or is aligned with the sheet engaging portion of the retainers. 
   As can be appreciated, a retainer of the type discussed above can also be incorporated into the sash members  92 - 95  to bias sheet  86  against the wall  100 . This arrangement could eliminate the need for the glass holding component  192  to secure the glass sheet  86  in place. 
   In the practice of the invention, when the compartment  110  (see  FIG. 3  is a sealed compartment, it is preferred to provide a desiccant in communication with the interior of the compartment to absorb or adsorb moisture captured in the sealed compartment  110  during manufacture and/or shipment of the unitless window sash. The invention is not limited to the manner in which the compartment communicates with the desiccant nor is the invention limited to the type of desiccant used. For example, the desiccant can be loose particles contained in a porous tube or a desiccant contained in a moisture pervious adhesive, e.g. of the type disclosed in U.S. Pat. Nos. 5,177,916; 5,531,047 and 5,655,280. The disclosure of the patents is hereby incorporated by reference. In the preferred practice of the invention, the desiccant is provided in the compartment between the sheets. 
   In one non-limiting embodiment of the invention, the desiccant is incorporated into a moisture impervious matrix to form a desiccating medium  304  that is applied to surface  302  of base  102 . As can now be appreciated, when the perimeter defined by the desiccating medium  304  on base  102  is smaller than the perimeter of the glass sheet  84  (see  FIG. 11 ), in order to avoid the edges of the sheet  84  contacting the desiccating medium  304  as the sheet  84  passes over the medium, the desiccating medium is applied to the base after the sheet  84  is in position in the sash frame. 
   As an alternative and with reference to  FIG. 3 , a channel  300  can be formed in surface  302  of the base  102  to receive the desiccating medium  304 . The size of the channel  300  is not limiting to the invention, and the channel can be any length, depth, width and/or configuration to accommodate more or less of the desiccating medium  304 . In this manner, the peripheral edge of sheet  84  will not contact the desiccating matrix  304  as the sheet is position on the sash frame. 
   Shown in  FIG. 9  are additional non-limiting embodiments of the invention for containing the desiccating medium  304  and allowing for the medium to be applied before the sheet  84  is moved into place. As can be appreciated the invention is not limited to the arrangements for containing the desiccating medium shown in  FIG. 9 , which are shown for purposes of illustration and not for purposes of limitation. 
   More specifically,  FIG. 9A  shows the desiccating medium  304  in a round cavity  310  in the base  102  of the sash members  92 - 95  (only sash member  92  shown in  FIG. 9 ). The rounded cavity  310  reduces the amount of desiccant visible when looking through the vision area of the window sash. The invention contemplates having sides  312  of the opening of the cavity  310  with a different durometer than the base  102  so that a nozzle can be inserted into the cavity for rapid filling, as will be discussed later. In addition, the rounded outer bottom surface  311  reduces the surface area exposed to the atmosphere as compared to a flat outer bottom, e.g. as shown in  FIG. 9E , and therefore, the desiccant in the cavity having the rounded outer bottom is expected to have a longer life than desiccant in a cavity having a flat outer bottom. 
     FIG. 9B  shows the desiccating medium  304  in a curvilinear shaped groove  313  formed in the base  102  of the sash members. The curvilinear shape of the groove allows for easier application of a barrier coat on the base  102  of the sash member.  FIG. 9C  shows the desiccating medium in a “V” shaped channel  314 . Because of the open upward end of the channel  314 , the use of nozzle tips of various shapes could be accommodated for varying the rate at which the desiccating medium can be applied to the channel  314 . This design also lends itself to easy application of barrier layer. 
     FIGS. 9D and 9E  show the desiccating medium  304  in a generally “U” channel  316  and  318 , respectively. The channel  316  shown in  FIG. 9D  incorporates flaps  320  on the topside of the channel which allow insertion of a nozzle into the channel  316  and lowers the amount of visible desiccant. The channel  318  shown in  FIG. 9E  does not incorporate the flaps  320  thereby allowing the entire width of desiccant to be seen.  FIGS. 9F and 9G  show the desiccating medium  304  in side pockets  324  and  326 , respectively. The orientation of the pockets  324  and  326  allows for the use of extruding nozzle tips to all be oriented in the same direction, e.g. when applying the layers  114  and  120  of adhesive sealant to the walls  98  and  100 , and applying the desiccating medium  304  in the pockets  324  and  326 . As can be appreciated the depth of the pockets  324  and  326  are not limiting to the invention and can be any depth to hold varying amounts of desiccating medium, e.g. the side pocket  324  shown in  FIG. 9F  is deeper than side pocket  326  shown in  FIG. 9G , and will hold more desiccating medium than the pocket  326 . The pocket depth is a factor to be considered when the volume of the compartment increases. For example, but not limiting to the invention, more desiccating medium is required for a patio door than for a window. The pockets  324  and  326  shown in  FIGS. 9F and 9G , respectively, also provide a means of hiding the desiccating medium  304 , making a more aesthetically pleasing window.  FIG. 9H  shows the desiccating medium  304  in a channel  328  having an interior faceted configuration that allows for greater capacity than the rounded channel  310  shown in  FIG. 9A  and also reduces surface tension of the desiccant. 
   The cavity  330  shown in  FIG. 9I  has a plurality of upright members  331 - 333 . The upright members are provided to secure the matrix containing the desiccant (see  FIG. 3 ) in the cavity  335  until it solidifies. In the event that the matrix does not readily adhere to the surface of the base  102  the upright  333  is provided with a rounded end  336  to secure the matrix in the cavity  335 . 
     FIG. 9J  is similar to  FIG. 9C  except that the cavity  340  has a flat bottom  341 . The flat bottom is preferred when using pop rivets of the type used in the art to seal vent holes and holes for moving insulating gas into the compartment  110  (see  FIG. 3 ). As can be appreciated, the base  102  can have the barrier layer  140  as discussed above and shown in  FIG. 3 . 
     FIG. 8  illustrates an embodiment of the invention that combines a desiccant cavity as shown in  FIG. 9A  with a sheet retaining device as discussed earlier. 
   As is appreciated by those skilled in the art, when a window having a sealed compartment filled with gas is transported to a higher altitude from a lower altitude and vice versa, e.g. moving from valleys to mountains, the pressure of the gas in the compartment is different from the gas acting on the outer surface of the glass sheets. When the difference is significant, a separation of the marginal edges of the sheets from its respective layer of adhesive sealant may occur. To maintain the difference between the gas pressure in the compartment and the gas pressure acting on the outer surfaces of the sheets at a minimum, vent holes or breather holes connecting the interior of the compartment to the environment are provided. The breather tubes can be left open so as to equalize the gas pressure inside the compartment  110  to the pressure outside the compartment when moving the window sash  80  from a low altitude to a higher altitude and vice versa. Once the unit arrives at its final destination, if desired the vent holes can be used to move a desired gas into the compartment and thereafter, the vent holes are sealed to retain the gas within the compartment. For a detailed discussion of breather tubes reference can be made to Glass Technical Document TD-103 published by PPG Industries Inc., which document is incorporated herein by reference. The vent holes, unlike breather tubes, are usually opened as needed to equalize the pressure in the compartment to the pressure acting on the outer surfaces of the glass sheets. 
     FIGS. 10A-10C  and  FIG. 11  illustrate several different breathe tube designs and  FIGS. 10D-10H  illustrate several different vent hole designs that can be used in the present invention. As can be appreciated the invention is not limited to the breather tubes or vent holes shown in  FIGS. 10 and 11  which are shown for purposes of illustration and not for purposes of limitation. Breather hole  340  shown in  FIG. 10A  includes a hollow conduit  342  having end portion  344  inserted in the base  102  of a sash member into the compartment  110 . Conduit  342  has a 90 degree bend to move the end portion  344  of the conduit against the base as shown in  FIG. 10A . The end portion  344  of the conduit  342  can be secured to the base  102  with sealant, glue, or other attachment material  348 . End portion  346  is accessible to fill the compartment  110  with an insulating gas and/or to seal the end portion  346 , e.g. by crimping the end of the conduit  342  and putting adhesive over the crimped end of the conduit to prevent gas from moving into or out of the compartment. Breather hole  360  shown in  FIG. 10B  includes a conduit  362  having end portion  363  inserted into a pop rivet  364  mounted in hole  366  in base  102 . Opposite end portion  368  of the conduit  362  extends away from the base and can be used to fill the compartment with an insulting gas and is sealed as discussed above to maintain the gas in the compartment  110 . Breather hole  370  shown in  FIG. 10C  includes a conduit  372  in hole  374  in the base  102 . The conduit  372  has a flared end  375  pushed into the hole  374  in the base  102  of the sash member so that the flared end retains the tube in the sash member. Optionally a sealant can be use to secure the flared end  375  in the hole. 
   With reference to  FIG. 11 , breather tube  376  has one end  377  of conduit  378  in the compartment between the glass sheets  460  and  462 . The conduit  378  extends through the body of the sash member  450  and has opposite end  379  extending out of the body of the sash member  450 . The portion  380  of the conduit  376  between its ends  377  and  379  is bent to the shape of a spring to accommodate the 12 inches or more of conduit in the confined space of the sash member. After the integrated window sash reaches its destination, the end  379  is crimped and adhesive sealant provided over the crimped end. 
   The venting holes  381  and  382  of  FIGS. 10D and 10E , respectively, include a desiccated breather module  388  combined with a hole  390  in the base  102 . The desiccated breather module  388  is not intended to replace the desiccating medium of the compartment  110 , but functions to remove moisture in the air moving from the environment into the compartment  110 . The module  388  can be connected to a conduit  392  as shown in  FIG. 10D  or a threaded connection  394  as shown in  FIG. 10E  having an end portion in the hole in the base  102  of the body of the sash member and the other end connected to a canister  396  of module  388  having a desiccant therein. A screw  398  is threaded into the threaded connection  394 . Rotating the screw in one direction provides communication between the outside environment through the canister to vent the compartment  110  and rotating the screw in the opposite direction seals the compartment against the environment after the pressure in the compartment has equalized to the pressure outside the chamber. The desiccant inside the canister  396  provides added drying capacity. Also, the canister can be replaced from time to time to replenish the desiccant drying power. 
     FIGS. 10F and 10G  illustrate mechanical venting methods.  FIG. 10F  includes a double threaded plug  410 . The first, smaller threaded portion  412  is screwed into a hole  414  in the base  102  of the sash member, and the second, larger threaded hole portion  416  extends beyond the base of the sash member. A through hole  418  goes through the center of the plug  410  to vent the gas in the compartment  110 . Once equilibration has been established, a cap  420  is screwed onto the larger threaded portion of the plug  416  to seal the vent hole.  FIG. 10G  shows a screw  424  threaded into hole  426  in the base  102  of the sash member. A second hole  428  is positioned in close proximity to the hole  426  such that head  430  of screw  424  extends beyond hole  428 . When screw  424  is loosened, air can pass through hole  428  into the compartment  110 . When screw  424  is tightened, the screw head  430  seals the hole  428 , and the compartment  110 . Optionally a gasket can be provided under the screw head  430  to enhance the sealing of the compartment  110 .  FIG. 10H  shows a pop-rivet  440  in hole  441  in the base  102  of the sash member; the pop-rivet  440  has a hollow body  442  which is filled with a SANTOPRENE plug  444  or other self sealing membrane. To vent the compartment  110 , the plug  444  is pierced, e.g. with a hypodermic needle  446 , allowing pressure equalization of the gas in the compartment  110  with the atmosphere. When the needle  446  is extracted from the plug  444 , the membrane self-heals sealing the compartment  110 . As an alternative, the entire plug can be a resilient, self-sealing material. 
   In the discussion regarding the non-limiting embodiments of the breather holes and vent holes shown in  FIG. 10 , a hole was provided in the base  102  of the sash member to provide communication with the interior of the compartment  110 . As can be appreciated; the invention is not limited thereto and communication with the interior of the compartment  110  can be made at different locations on the window sash, e.g. but not limited to a hole in one or more of the glass sheets. 
   As can now be appreciated, the invention is not limited to the number of sheets of the insulating unitless window sash of the invention. For example and with reference to  FIG. 11 , each sash member  450  of sash frame  452  includes walls  454 ,  456  and  458  for receiving peripheral and marginal edges of sheets  460 ,  462  and  464 . Walls  460  and  462  are separated by base  466  and walls  462  and  464  are separated by base  468 . The desiccating medium  304  can be provided on the base  466  between the sheets  460  and  462 , and optionally, a bead  472  can be provided on base  468  between sheets  462  and  464 . As can be appreciated, the sheet  462  can be a glass sheet or a plastic sheet having an environmental coating of the types taught in the art to increase the insulating value of the unitless window sash or can be a decorative panel such as those used in art glass applications. 
   Although not limiting to the invention, and with continued reference to  FIG. 11 , in one non-limiting embodiment of the invention, sash members, e.g. sash member  450  shown in  FIG. 11  can include glass-centering ramps  476 ,  478  and  480  located at the bottom portion of the walls  454 ,  456  and  458 , respectively. The glass centering ramps are essentially chamfers that are extruded (for vinyl sash) or milled (for wood sash) along at least a portion of each sash member, and in one non-limiting embodiment, along the entire length of each sash member. The ramps allow the glass sheets  460 ,  462  and  464  to be dropped into place during assembly, while restricting lateral movement. By allowing the glass to slide down the ramp, the glass is centered with minimal effort. As can be appreciated the ramps shown in  FIG. 11  can be used with the sash members  92 - 95  discussed above. As can be further appreciated, the retainer devices shown in  FIG. 8  and discussed above can be used to retain the sheets  460  and  462  in position. Further the vent holes shown in  FIG. 10  and discussed above can be used to equalizing the pressure in the space between adjacent sheets  460  and  462  and adjacent sheets  462  and  464  when transporting the unitless sash from one altitude another different altitude. 
   It is contemplated in the assembly of a glazing unit of the type discussed herein that muntin bars can be used to simulate a multi-paneled unit as shown in  FIG. 12 . To achieve this effect, in one embodiment of the invention, muntin bars  490  are positioned in the sash frame  88  after the first sheet  84  is in position but prior to the positioning of the second sheet  86 . Referring to  FIG. 13 , the muntin bars  490  are held in place between the glass sheets  84  and  86  by a clip  492  that is inserted into the end of a muntin bar  490 . Base  494  of the clip  492  is shaped and constructed so that when placed between the two glass sheets  84  and  86 , it will compress and hold the muntin bars in place. More specifically and referring to  FIG. 14 , the muntin clip  492  consists of two areas: the top or Christmas tree  496  that is inserted into the ends of the muntin bar, and the compressible base  494 . The base  494  of the clip  492  is larger than the space between the two glass sheets  84  and  86 . In this manner, when the clip  492  is between the sheets  84  and  86  and the sheets are in position in the sash frame, the sheets will compress the base  494  and will hold the clips  492  in place. In the particular non-limiting embodiment of the invention shown in  FIG. 14 , the base  494  is basically circular in shape and has a plurality of cutout areas  500  to allow the base to compress more easily. It is contemplated that the base  494  can have a variety of different shapes and can also be solid. 
   More particularly and with reference to  FIGS. 15 and 16 , there are shown additional non-limiting embodiments of a base  502  and  504  for clips  514  and  515 , respectively, of the invention. The base  502  has generally straight surfaces  506  and  508  for engaging the inner surface of adjacent sheets, e.g. inner surface of the sheets  84  and  86 , and open sides  510  and  512 . The open sides  510  and  512  allow base  502  to compress without excess deformity of the base. The base  504  has a pair of opposed sides  516  and  518 , each side having a plurality of fingers, e.g. three spaced fingers  519 ,  520  and  521 . The fingers  519 ,  520  and  521  engage the inner surfaces of the sheets. The three spaced fingers provide for compression of the base without excess deformation of the base  504 . 
   Shown in  FIG. 17  is a muntin clip  524  that includes a cylinder  525  having a connection  496  to the muntin bars, e.g. a tree-like configuration as discussed earlier, on the outer surface and end caps  527  and  529 , preferably captured in the ends of the cylinder in any convenient manner. The end caps are biased away from one another by a spring  530 . In the practice of the invention, but not limiting thereto, after the sheet  84  (see  FIG. 3 ) is mounted in the sash frame as previously discussed, the muntin lattice is place in the sash frame with one of the end caps, e.g. end cap  527  engaging the inner surface of the sheet  84 . Thereafter the sheet  86  is placed in the sash frame on the end cap  529 . As the sheets move together the end caps move toward one another against the biasing action of the spring  530  to secure the clip  524  in position between the sheets  84  and  86 . As can be appreciated, the clip  524  without the tree connector can be used as a retainer to bias the sheet  84  against the wall  98  as was discussed for the retainers shown in  FIG. 8A . 
   Although not required, the material used in the making of the clips  492 ,  514 ,  515  and  524  should be resistant to ultraviolet exposure, made of a thermoset plastic to survive elevated temperatures in the event an oven heating is necessary during the fabrication of the unit, and the base must not compress to the extent that it becomes loose between the glass sheets. Non-limiting examples of material that can be used to fabricate the clip include nylon, polypropylene and injection moldable plastic. 
   Although the clips  492 ,  514 ,  515  and  524  were discussed for use with the integrated window sash of the invention, it can now be appreciated that the clip can also be used to secure muntin bars  490  between the glass sheets  36  and  38  of the prior art glazing unit  32  discussed above and shown in  FIG. 1 . More particularly, with varying air spaces, the clips  492 ,  514 ,  515  and  524  will vary in size to accommodate the differences, although a clip designed for a certain air space thickness can accommodate another air space if the difference in thickness is small. The compression range of the base  494  provides a wide array of interference fits, making it useful in a variety of spacer/sealant systems. Because the clips  492 ,  514 ,  515  and  524  are not physically inserted into a spacer element, e.g. the surface of a spacer frame facing the space between the glass sheets or the sash members of the unitless sash of the instant invention that holds the glass sheets in spaced apart relation, the clips  492 ,  514 ,  515  and  524  are usable in a variety of insulating glass unit systems such as Intercept®, Swiggle®, Super Spacer®, Insuledge®, and TPS® systems, as well as other types of systems that use an aluminum, plastic or fiberglass spacer frame. 
   In addition, the type of sealant system used to seal the glazing unit will not affect the use of this clip. The clips  492 ,  514 ,  515  and  524  will be compatible with single seal, (both thermoplastic and room temperature curing) double seal, (these double seal units can be made using a variety of sealants in combination) or any other edge configuration used in the making of an insulating-glass unit. 
   With reference to  FIG. 11 , in another non-limiting embodiment of the invention, muntin bars  490  are secured to the surface of a sheet, e.g. but not limiting to the invention, inner surface of the glass sheet  460  by a double backed tape  556  having one surface of the tape adhered to the muntin lattice and the opposite side of the tape adhered to the inner major surface of the sheet. Optionally, instead of using double back tape, a compressible material similar to the material of the base  494  of clip  492  having adhesive surfaces mounts the muntin bars to the sheet surface. 
   In the fabrication of the window sash of the invention, the sealants and/or desiccant can be individually or simultaneously extruded onto surfaces of the individual sash members or a preassembled window sash through an extruder head or a multi-head extruder. Depending on the configuration of the desiccant groove (see  FIG. 9  and the discussion relate thereto), a nozzle  600  of an extruder head may be in line with a sealant nozzles  602  or perpendicular to the sealant nozzles  602 , for example as shown in  FIG. 18 . The nozzle could be a one multi-port nozzle or include multiple individual nozzles that will allow for the simultaneous application of the desiccant medium  304  in or on base  102  and the layers  114  and  120  of the adhesive sealants in the sealant grooves  128  and  132  of walls  98  and  100 , respectively. The nozzles can be used to apply hot (such as hot melt butyls and DSE sealants) and/or room temperature sealants (polyurethanes, polysulfides, silicones, etc.) and desiccant materials. Nozzle tips can be various shapes depending on groove configuration. The nozzle controls the amount of material applied to achieve desired shape and thickness of sealant bead. 
   In the fabrication of insulating units it is preferred to have dry gas in compartment  110  shown in  FIG. 3 , between adjacent sheets e.g. air, krypton, argon or any other type of thermally insulating gas. When air is the insulating gas, the glazing unit can be fabricated in the atmosphere to capture the atmosphere in the compartment between the sheets as the window sash is assembled. In the instance where an insulating gas is of a particular purity or other than atmospheric air is desired in the compartment, one or more vent holes  620 , as shown in  FIG. 3 , can be provided through one or more webs of one of the sash members. The holes  620  provide a passageway from compartment  110  to the peripheral edge  622  of the sash frame  88 . Gas is moved into the compartment  110  through the holes  620  or through a conduit  378  as shown in  FIG. 11  in any usual manner, e.g. as disclosed in U.S. Pat. No. 5,531,047, which disclosure is hereby incorporated by reference. After the compartment  110  is filled, at least the hole  620  in the base  102  of the sash member or the conduit is hermetically sealed. As can be appreciated, the compartment  110  between the sheets  84  and  86  can be open to the environment by having holes moving air into and out of the compartment e.g. as disclosed in U.S. Pat. No. 4,952,430, which patent is hereby incorporated by reference. When air is continuously moved into and out of the compartment, any coating on the inner surfaces  198  and  124  of the glass sheets  84  and  86 , respectively, should be capable of being in continuous contact with the atmosphere without deterioration. Further, the coating disclosed in U.S. Pat. No. 6,027,766 discussed above can be used on the inner surface of the glass sheets. Still further, the compartment between the sheets can be connected to the environment by way of a tube filled with a desiccant, e.g. as is known in the art. In this manner, air moves into and out of the compartment through the desiccant. 
   The integrated window sash having an insulating vision area incorporating features of the present invention provides an economical window sash having improved thermal performance. The window sash is economical to make because it eliminates the need to make an insulating unit. The window sash has improved performance because the window heat gain and loss is through the frame and not the edge area of the insulating glazing unites. Using sashes made from hollow core extruded vinyl; foam filled extruded vinyl, cellular structural foam materials, plus extruded wood/plastic composites in the practice of the invention would be expected to gain similar thermal performance improvements. The integrated window sash of the invention does not require that edges of sputtered coated glass be removed because the coating is on the inner surface of the glass and the layer of the adhesive sealant is on the outer surface of the sheet. 
   As discussed earlier, it is contemplated that the sash members can be co-extruded with selected other features of the sash frame. These additional features can be the same as or be a different material from the remaining portion of the sash member. For example and without limiting the present invention, the following is a list of sash frame components that can be co-extruded with the sash member. It should be appreciated that combinations of these components can also be co-extruded with the sash member.
         a) A desiccant: this would eliminate the need for a secondary application of a desiccant, and   b) An adhesive sealant: this would eliminate the need for a secondary application of the adhesive-sealants.       

   It is also contemplated that the sash members can be extruded as discussed above and a metal tape or foil be applied to the base of the member as it is being formed or very soon thereafter. In this manner, a continuous sash member can be formed with the barrier layer already applied so that the sash member can be further processed to produce a sash frame and integrated window sash. 
   It should be appreciated that other processes can be used to form the sash members. For example, rather than being extruded to the desired shape, the cross-section can be formed by a pultrusion process, as is well know in the art. In a pultrusion process, fiber glass strands are typically used as a reinforcement. Fiber glass is pulled through a die having the desired cross section and the desired polymeric material is formed around the fiber glass as it is pulled. Using this type of process, the barrier layer can also be formed over the base portion of the sash member. More specifically, a plastic layer can be formed on the base as the sash member is formed, or a metal layer can be applied to the base of the member as it is being formed or very soon thereafter. 
   Based on the description of the embodiments of the invention, it can be appreciated that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications that are within the spirit and scope of the invention, as defined by the appended claims.