Patent Publication Number: US-6662389-B1

Title: Composite fabric and fabric product with variable thermal insulation

Description:
TECHNICAL FIELD 
     The present invention relates in general to composite fabrics and in particular to composite fabrics with features that allow user adjustment of the fabric thermal insulation properties. 
     BACKGROUND INFORMATION 
     Man has been using clothing for a considerable time to help in the adaptation to the world&#39;s variable and sometimes harsh environment. Because of the many variations in the world&#39;s environment, the fabric that makes up clothing is required to do many duties. Sometimes the environment requires insulation to protect against cold temperatures. Many times these cold temperatures are accompanied with wind and rain. Therefore the fabrics that makes up the clothing may need to be able to keep water out while also keeping heat next to the clothing wearer where it is needed. If the cold weather occurs during sunny conditions, then the user may be faced with having to change clothing as the temperature varies. Usually this is done by applying clothing in layers. When the clothing is in layers, then the user may remove selected layers of clothing as the temperature warms up. While wearing clothing in layers is effective, many times it is cumbersome to remove and store the clothing layers. 
     Some companies (e.g., Gore Tex Corp.) have developed materials with a fabric pore size such that water molecules cannot penetrate yet water vapor can escape. While this solves the problem of keeping moisture out and at the same time allowing the fabric to breathe, it does not solve the problem of how to deal with a requirement for a variable thermal insulation for clothing. For example, if one dresses for a cold morning and the sun comes out, then the additional thermal energy may require a person to remove clothing layers or to make some adjustment for the added heat load. 
     A dead air space is known to be a very good thermal insulator. This concept is used effectively in air mattresses and other inflatable materials to provide insulation or cushioning. While some manufacturers have tried to use air in materials for garment clothing, it has resulted in bulky garments with a very course control of insulation. Most of these manufacturers use the thickness of the air space to control the amount of insulation. Since creating pockets of air requires that the pockets be impervious to the air molecule, this precludes the use of materials that naturally breathe. It is difficult to design a composite fabric that allows the use of air as an insulator, allows easy inflation and deflation, and allows the use of materials that naturally breathe. 
     Sometimes it is desirable for clothing required for variable weather conditions to have the ability to vary its thermal insulation at selected areas rather than over the entire garment. In this way, only those portions of a user&#39;s body that need additional insulation would be affected. For example, one may have their back against damp ground while their front is exposed to direct sunlight. It would be desirable to be able to change the thermal insulation of the garment covering one&#39;s back to have one thermal insulation value while adjusting the thermal insulation of the garment covering the front to have a different thermal insulation value. 
     There is, therefore, a need for a composite fabric that enables adjustments of thermal insulation in selected areas while maintaining the ability to use fabrics that naturally breathe in other selected areas. 
     SUMMARY OF THE INVENTION 
     A composite fabric is formed by attaching one or more expandable bladders to a surface of a first fabric layer at spaced intervals across the surface and extending corresponding bladder lengths across the surface in a direction substantially transverse to a direction of the spaced intervals. The expandable bladders define fabric areas of the first fabric layer adjacent to each of the corresponding bladder lengths of the expandable bladders. In one embodiment, each expandable bladder is attached to the first fabric layer by one or more fabric loops. The expandable bladders are threaded through corresponding fabric loops that extend across the surface of the fabric layer. The expandable bladders are coupled, singly or in groups, via an air valve that connects to an air source for selectively inflating and deflating the expandable bladders. When selected, expandable bladders are inflated and deflated and the fabric areas along and adjacent to the selected expandable bladders are selectively covered and uncovered by the selected expandable bladders. In this manner, the thermal insulation of the defined fabric areas of the fabric layer are varied. 
     In one embodiment, the fabric loops extend continuously across the fabric layer. Each fabric loop is made from a non-stretch fabric and essentially hangs in folds when the expandable bladders in the fabric loops are deflated. The fabric loops may be porous and offer little insulation value so that the characteristics of the first fabric layer are preserved when not covered by expandable bladders. The expandable bladders may be made to have a certain compressed shape when the air inside is evacuated. In another version of this embodiment, the fabric loops are segmented across the length of the fabric layer and do not cover the entire bladder lengths of corresponding threaded expandable bladders. 
     In another embodiment of the present invention, the fabric loops are made from a material that, while porous, stretches in a radial direction with little or no length expansion. The expandable bladders are threaded through corresponding fabric loops and assume a compressed shape smaller than the diameter of a non-expanded fabric loop. When air is supplied to selected expandable bladders, they unfold, expand, and stretch their corresponding fabric loops thereby selectively covering the fabric area adjacent to and along the bladder lengths of the selected expandable bladders. In this manner, the thermal insulation of the fabric area of the selected expandable bladders is varied. In this embodiment, the fabric loops may also be segmented across the length of the fabric layer. 
     In one embodiment, the expandable bladders are made as tubes of thin material that may be folded to a minimum cross-section within a fabric loop. When the expandable bladders are pressurized with air, they unfold and either fill or expand a corresponding fabric loop. In another embodiment, the expandable bladders have a cross-section geometry designed so that they assume a certain collapsed shape when evacuated. These extendable bladders unfold in a controlled geometry when filling or expanding a corresponding fabric loop. In yet another embodiment, the expandable bladder is made from a balloon-like structure that expands rapidly to a fixed diameter when inflated. The tapered wall thickness of a balloon-like expandable bladder causes its expansion to progress along its bladder length as it is pressurized. This balloon-like expandable bladder varies the thermal insulation of the fabric layer by selectively covering and uncovering the fabric area as its inflation and deflation progresses across its bladder length. 
     The composite fabric may be used to make fabric products with various functional shapes. For example, a fabric garment may be made by piecing together sections of composite fabric made according to embodiments of the present invention. A user may selectively inflate expandable bladders to modify and control the thermal insulation across selected areas of the fabric garment. Various fabric products may be formed by using the composite fabric made according to embodiments of the present invention including, but not limited to, tents, sleeping bags, backpacks, shoes, boots, and garments worn by an individual. 
     The expandable bladders may be coupled to an air source with various air valves so that a user may also selectively inflate and deflate expandable bladders. The expandable bladders may also be connected in series so that an entire area of the fabric layer may be controlled with one air valve. The couplings that connect expandable bladders in series may be designed to be flexible to facilitate bending a composite fabric layer. 
     The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which: 
     FIG. 1 illustrates a fabric layer having expandable bladders coupled with fabric loops that do not stretch; 
     FIG. 2 illustrates a fabric layer having expandable bladders coupled with segmented fabric loops that do not stretch; 
     FIG. 3 illustrates a fabric layer having expandable bladders coupled with fabric loops that do stretch; 
     FIG. 4 illustrates a fabric layer having expandable bladders coupled with segmented fabric loops that do stretch; 
     FIGS. 5A,  5 B, and  5 C illustrate three types of expandable bladders usable in embodiments of the present invention; 
     FIGS. 6A and 6B illustrate the geometry and dimensions of fabric loops when inflated and deflated; 
     FIG. 7 illustrates a fabric layer with fabric loops with expandable bladders connected to an air source via air valves and an inflation tube; 
     FIG. 8 illustrates a fabric layer with segmented fabric loops with expandable bladders connected to an air source via air valves and an inflation tube; 
     FIGS. 9A,  9 B, and  9 C illustrate non-stretch fabric loops with different types of expandable bladders in various stages of inflation; 
     FIGS. 10A,  10 B, and  10 C illustrate stretchable fabric loops with different types of expandable bladders in various stages of inflation; 
     FIG. 11 illustrates a number of expandable bladders coupled together in series with flexible adapters that allow the composite fabric to bend along the width axis; 
     FIG. 12 is a flow chart of method steps in an embodiment of the present invention; 
     FIGS. 13A,  13 B, and  13 C illustrate some various ways fabric loops may be fabricated; 
     FIGS. 14A and 14B illustrate how the area adjacent to and along selected expandable bladders is modified by inflating and deflating the selected expandable bladders; 
     FIG. 15 illustrates details of an expandable bladder that is designed to collapse to a certain shape when evacuated; and 
     FIGS. 16A and 16B illustrate two fabric products made with composite fabric according to one embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION 
     In the following description, numerous specific details are set forth to provide a thorough understanding of the present invention. However, it will be obvious to those skilled in the art that the present invention may be practiced without such specific details. For the most part, details concerning manufacturing processes, materials and the like may have been omitted in as much as such details are not necessary to obtain a complete understanding of the present invention and are within the skills of persons of ordinary skill in the relevant art. 
     Refer now to the drawings wherein depicted elements are not necessarily shown to scale and wherein like or similar elements are designated by the same reference numeral through the several views. 
     FIG. 1 illustrates composite fabric  100  made according to an embodiment of the present invention using fabric layer  101  with width  130  and length  131 . Fabric layer  101  has fabric loops  106 - 109  attached along its length  131  and spaced at intervals  133  across its width  130 . While the space intervals  133  are shown uniform in FIG. 1, non-uniform space intervals are within the scope of the present invention. Expandable bladders  102 - 105  are threaded through corresponding fabric loops  106 - 109 . Fabric layer  101  may be made from regular material or a special material, for example, a special material that passes water vapor while blocking liquid water. The embodiment of FIG. 1 illustrates fabric loops  106 - 109  that do not stretch, but rather assume a form dictated by the expansion of corresponding expandable bladders  102 - 105 . Likewise, expandable bladders  102 - 105  may be made to expand by unfolding or stretching and thinning their corresponding wall thickness. Area  132  is defined as the space along and adjacent to expandable bladders  102  and  103 . Area  132  is partially covered by the areas occupied by deflated expandable bladders  102  and  103 . Since the areas occupied by deflated expandable bladders  102  and  103  are small relative to area  132 , the characteristics of fabric layer  101  in area  132  are only slightly modified by the presence of the material of expandable bladders  102  and  103 . The material of fabric loops  106 - 109  may be made porous so that fabric loops  106 - 109  do little to alter the characteristics of fabric layer  101  when their corresponding expandable bladders  102 - 105  are deflated. While fabric layer  101  is shown as a rectangular shape with a length  131  and width  130 , it is understood that fabric layer  101  may have any regular or irregular shape and still be within the scope of the present invention. Illustrating fabric layer  101  with a regular length and width is used only to facilitate explanation of the present invention. The intervals between expandable bladders (e.g., D  133 ) are sized such that expandable bladders  102 - 105 , when fully expanded, will substantially cover and maximally insulate an area of fabric layer  101 . For example, when exemplary expandable bladders  102  and  103  are fully expanded (not shown expanded in this view), area  132  is thermally insulated by the volume of air contained within expandable bladders  102  and  103 . Additionally air may be trapped between the expandable bladders  102  and  103  which also add insulation. 
     FIG. 2 illustrates composite fabric  200  having fabric layer  241  with width  230  and length  231 . Fabric layer  241  has expandable bladders  209 - 212  attached with segmented fabric loops  201 - 208 . Segmented fabric loops  201 - 208  hold corresponding expandable bladders  209 - 212 . Fabric layer  241  may be made from regular material or special material, for example, a special material that passes water vapor while blocking liquid water. It may be desirable to use segmented fabric loops  201 - 208  to attach the corresponding expandable bladders  209 - 212  to reduce the bulk of the composite fabric panel  200 . Fabric area  232  is formed by the area along and adjacent to expandable bladders  209  and  210 . The fabric loops  201 - 208  are shown attached at uniform intervals  233  but may also be attached at non-uniform intervals and still be within the scope of the present invention. The intervals between expandable bladders (e.g., D  233 ) are sized such that expandable bladders  209 - 212 , when fully expanded, will substantially cover and maximally insulate fabric layer  241 . For example, when exemplary expandable bladders  209  and  210  are fully expanded (not shown expanded in this view), area  232  is thermally insulated by the volume of air contained within expandable bladders  209  and  210 . Additionally air may be trapped between the expandable bladders  209  and  210  which also add insulation. 
     FIG. 3 illustrates composite fabric  300  in another embodiment of the present invention. Composite fabric  300  is made with fabric layer  341  having width  330  and length  331 . Fabric layer  341  has expandable bladders  305 - 308  attached with fabric loops  301 - 304  made from a material that stretches in a certain direction (e.g., Lycra® material). Expandable bladders  305 - 308  are threaded through corresponding fabric loops  301 - 304 . Fabric loops  301 - 304  are spaced at intervals (e.g., D  333 ) along the width  330  of fabric layer  341 . These intervals are sized so that the expanded diameters of adjacent ones of fabric loops  301 - 304  substantially touch when their corresponding threaded expandable bladders  305 - 308  are fully inflated. For example, when exemplary expandable bladders  305  and  306  are fully inflated (not shown expanded in this view), fabric area  332  is covered and is thermally insulated by the volume of air contained within expandable bladders  305  and  306 . See, for example, FIG. 7 illustrating fully expanded bladders  717  and  718 . 
     FIG. 4 illustrates composite fabric  400  in another embodiment of the present invention. Composite fabric  400  is made with fabric layer  441  having width  430  and length  431 . Fabric layer  441  has expandable bladders  409 - 412  attached with fabric loops  401 - 408  made from a material that stretches in a certain direction (e.g., Lycra® material). Expandable bladders  409 - 412  are threaded through corresponding fabric loops  401 - 408 . Fabric loops  401 - 408  are spaced at intervals (e.g., D  433 ) along the width  430  of fabric layer  441 . These intervals are sized so that the expanded diameters of adjacent ones of fabric loops  401 - 408  substantially touch when corresponding expandable bladders  409 - 412  are fully inflated. For example, when expandable bladders  409  and  410  are fully inflated, fabric area  432  is covered and is thermally insulated by the volume of air contained within expandable bladders  409  and  410 . It may be desirable to use segmented fabric loops  401 - 408  to attach the corresponding expandable bladders  409 - 412  to reduce the bulk of the composite fabric  400 . 
     FIGS. 5A,  5 B and  5 C illustrate various types of inflatable bladders that may be used in embodiments of the present invention. In FIG. 5A, inflatable bladder  501  is shown in its inflated state  503  and deflated state  502 . Inflatable bladder  501  is of the type that unfolds when it is inflated and expands without stretching. For example, the cylindrical plastic tube used to protect a delivered newspaper illustrates a bladder like inflatable bladder  501 . When air is removed, inflatable bladder  501  may flatten under external air pressure and may not assume any particular shape. Inflatable bladder  501  may be further compressed if threaded through a fabric loop (e.g., fabric loop  301 ) that contracts when not expanded. 
     FIG. 5B illustrates expandable bladder  504  that is also a type that expands by unfolding. Expandable bladder  504  is formed in such a way that it has a cross-section of a certain shape (e.g., star shaped) under no inflation pressure (internal pressure ambient atmospheric pressure). FIG. 15 shows additional details of expandable bladder  504  which is star shaped. A star shaped cross-section may be made by controlling wall thickness&#39; of expandable bladder  504  during formation. In this way, expandable bladder  504  may be pressurized to a full, substantially circular cross-section or evacuated to a minimum size with a compressed star shaped cross-section. Expandable bladder  504  may be used with either a fabric loop corresponding to exemplary fabric loop  106  or fabric loop  301 . Expandable bladder  504  is shown in compressed state  505  and expanded state  506 . Cross-sections other than star shaped may be used and still be within the scope of the present invention. 
     FIG. 5C illustrates expandable bladder  507  which is yet another type useable with embodiments of the present invention. Expandable bladder  507  is made like a standard cylindrical balloon that assumes an elongated cylindrical shape when inflated. Expandable bladder  507  is shown in its deflated state  508 . When pressurized air is supplied to expandable bladder  507 , it substantially expands fully to its maximum diameter at a position determined by its tapered wall thickness. In its partially expansive state  509 , expandable bladder  507  “pops” to its full diameter and then progressively expands (edge  510  progresses) along its length. If an inflatable bladder like  507  is inserted into an exemplary fabric loop  106 , it expands a section of fabric loop  102  during the initial stages of expansion. If fabric loops  106  and  107  both had expandable bladders like  507 , then the portion of area  132  of fabric layer  101  that is blocked would increasingly progress along the length of fabric loops  106  and  107 . 
     FIGS. 6A and 6B illustrate characteristics of the two types of fabric loops, for example, fabric loop  600  that does not stretch to expand and fabric loop  609  that stretches in a certain dimension when expanded. In FIG. 6A, fabric loop  600  is of the type that does not substantially stretch when expanded. Width W  606  represents the width of fabric loop  600  when flattened in its unexpanded state  601 . When fabric loop  600  is fully expanded, it assumes a circular shape with a diameter D  607  illustrated in expanded state  602 . Since the circumference of the circular shape of fabric loop  600  is equal to 2*W  606 , the circular diameter of fabric loop  601  is 2*W  606 /π when it is fully expanded. For adjacent fabric loops (e.g., fabric loops  102  and  103 ) like fabric loop  600  to touch when inflated, they may be spaced at an interval substantially equal to diameter D  607  or 2*W  606 /π. Since W  606  is greater than 2*W  606 /π, adjacent exemplary fabric loops  102  and  103  may overlap when not inflated and flattened. However, the material of the fabric loops like fabric loop  601  may be porous and designed to minimally affect the characteristics of a corresponding fabric layer (e.g., fabric layer  101 ) to which it is attached. 
     FIG. 6B illustrates fabric loop  609  that is of the type that expands by stretching. Fabric loop  609  is shown in its unexpanded state  603  and has a diameter Dc  605 . When inflated, fabric loop  609  expands to a diameter De  608 . If an expandable bladder like  501  or  504  is threaded in a fabric loop  603 , then the diameter Dc  605  is sized to contain the bladder in its compressed state, for example compressed state  502  or compressed state  505 . Fabric loop  609  may be designed to stretch preferably in diameter and only minimally length by using a material like Lycra®. 
     FIG. 7 illustrates a composite fabric  700  made using a fabric layer  761 . Composite fabric  700  is made using an embodiment of the present invention where fabric layer  761  has various expandable bladders  713 - 722  threaded through corresponding fabric loops  701 - 710  and coupled to an air source  712  via an inflation tube  730 . In this illustration, expandable bladders  713  and  714  are coupled to inflation tube  730  with air valve  723 . Likewise, expandable bladders  715  and  716  are coupled to inflation tube  730  with air valve  724 . Expandable bladders  717  and  718  are coupled to a inflation tube  730  with air valve  725 , and expandable bladders  719 - 722  are coupled to inflation tube  730  with air valve  726 . Having various expandable bladders coupled to an air source with separate air valves allows the degree of inflation of the selected expandable bladders to be individually controlled. For example, expandable bladders  713  and  714  are shown substantially deflated. Expandable bladders  715  and  716  are shown partially expanded, while expandable bladders  717  and  718  are shown fully expanded. Expandable bladder  719 - 722  are also shown substantially deflated. The fabric area  740  along and adjacent to expandable bladders  713  and  714  is substantially uncovered and substantially has the material characteristics of the material making up fabric layer  761 . These material characteristics include thermal insulation, moisture transmission, and water vapor transmission. Fabric area  741  along and adjacent to partially inflated expandable bladder  716  and fully inflated expandable bladder  717  is partially covered by bladders  716  and  717  and their corresponding fabric loops  704  and  705 . Most of the area  741  is thermally insulated by the air volume contained in expandable bladders  716  and  717 . The small uncovered portion of area  741  would maintain the characteristics of the material of fabric layer  761 . Fabric area  742 , between fully inflated expandable bladders  717  and  718 , is shown completely closed covered and insulated by the air in expandable bladders  717  and  718 . Since expandable bladders  717  and  718  are air tight, they would also block water vapor or liquid water. Air source  712  has a air valve  750  that may be opened when air valves  723 - 726  are closed. Air source  712  may then be evacuated creating a vacuum. If selected ones of air valves  723 - 726  are then opened, the corresponding coupled expandable bladders  713 - 722  may be deflated below ambient air pressure. Air source  712  may be as simple as an air bulb used on blood pressure testing units. Controllable check valves are contained in the air valves  750  and  751  so that air may be correctly directed when inflating and deflating expandable bladders leaving multiple air valves  723 - 726  to simple pass or block air flow to their corresponding expandable bladders. Other fabric areas adjacent to other expandable bladders in FIG. 7 which experience a variable thermal insulation may not be highlighted or numbered to minimize the detail on FIG.  7 . 
     FIG. 8 illustrates composite fabric  800  with fabric layer  861 . Composite fabric  800  is made using an embodiment of the present invention where fabric layer  861  has various expandable bladders  801 - 810  coupled to an air source  812 . Expandable bladders  801 - 810  are threaded through corresponding attached segmented fabric loops. For example, expandable bladder  801  is coupled to fabric layer  861  with segmented fabric loops  831 - 833 . Likewise, expandable bladder  810  is coupled to fabric layer  861  with segmented fabric loops  834 - 836 . 
     In FIG. 8, expandable bladders  801  and  802  are coupled to inflation tube  830  with air valve  823 . Likewise, expandable bladders  803  and  804  are coupled to inflation tube  830  with air valve  824 . Expandable bladders  805  and  806  are coupled to a inflation tube  830  with air valve  825  and expandable bladders  807 - 810  are coupled to inflation tube  830  with air valve  826 . Having various expandable bladders coupled to an air source with separate air valves allows the degree of inflation or deflation of selected expandable bladders to be individually controlled. For example, expandable bladders  801  and  802  are shown substantially deflated. Expandable bladders  803  and  804  are shown partially inflated, while expandable bladders  805  and  806  are shown fully inflated. Expandable bladders  807 - 810  are also shown substantially deflated. The fabric area  840  of fabric layer  861  between expandable bladders  801  and  802  is substantially uncovered and has the characteristics of the material making up fabric layer  861  including thermal insulation and moisture and water vapor transmission. Fabric area  841  between partially inflated expandable bladder  804  and fully inflated expandable bladder  805  is partially covered by expandable bladders  804  and  805 . Most of the fabric area  841  is thermally insulated by the air volume contained in expandable bladders  804  and  805 . The small uncovered portion of fabric area  841  would retain the material characteristics of the material of fabric layer  861 . The fabric area  842 , between fully inflated expandable bladders  805  and  806 , is shown completely covered and insulated by the air in expandable bladders  805  and  806 . Since expandable bladders  805  and  806  are air tight, they would naturally also block water vapor or liquid water. Air source  812  has an air valve  850  that may be opened when air valves  823 - 826  are closed. Air source  812  may then be evacuated creating a vacuum. If selected ones of air valves  823 - 826  are then opened, the corresponding coupled expandable bladders  801 - 810  may be deflated below ambient air pressure. Air source  812  may be as simple as an air bulb used on blood pressure testing unit. Controllable check valves are contained in the air valves  850  and  851  so that air may be correctly directed when inflating and deflating expandable bladders  801 - 810  leaving multiple air valves  823 - 826  to simple pass or block air flow to their corresponding expandable bladders  801 - 810 . Other fabric areas adjacent to other expandable bladders in FIG. 8 which experience a variable thermal insulation may not be highlighted or numbered to minimize the detail on FIG.  8 . 
     FIGS. 9A,  9 B, and  9 C illustrate various fabric loops  901 ,  904 , and  905  with various expandable bladder types  902 ,  903 , and  906 . Progressing from left to right, fabric loop  901  is shown expanding as corresponding expandable bladder  902  inflates. FIG. 9A illustrates fabric loop  901  which is substantially flat when expandable bladder  902  is deflated. As expandable bladder  902  inflates, it contacts the walls of fabric loop  901  and fabric loop  901  will eventually assume the shape of expandable bladder  902 . In this embodiment, fabric loop  901  is designed not to stretch. 
     FIG. 9B illustrates expandable bladder  903  in fabric loop  904 . Expandable bladder  903  has a star shaped cross-section (see detail illustrated in FIG. 15) that has a certain shape when deflated and collapsed. As expandable bladder  903  is pressurized, it will expand while keeping its star like shape characteristic. Eventually, expandable bladder  903  will expand to the constraints of fabric loop  904  and assume a substantially circular shape. 
     FIG. 9C illustrates fabric loop  905  which contains expandable bladder  906  that has a crumpled deflated state with no particular geometry. As expandable bladder  906  is pressurized, it unfolds and starts to assume a somewhat circular shape. When expandable bladder  906  is fully expanded, it also will assume a circular shape corresponding to the constraints of fabric loop  905 . 
     FIGS. 10A,  10 B, and  10 C illustrate three types of extendable bladders  1002 ,  1004 , and  1006  threaded through corresponding fabric loops  1001 ,  1004 ,  1005  that stretch when expanded. Fabric loops  1001 ,  1003 ,  1005  stretch and assume the inflated shaped of their corresponding expandable bladders  1002 ,  1004 , and  1006  and these fabric loops may aid to compress their corresponding expandable bladder to a minimum size when they are deflated. Fabric loops  1001 ,  1003 , and  1005  may be made from a Lycra® material that stretches primarily in a radial direction and minimally in length. Extendable bladders  1002 ,  1004 , and  1006  may be one of the described types (e.g., expandable bladders  501  and  504 ) that compress to a minimum cross-section when deflated aided by the contraction force of their corresponding stretched fabric loops  1001 ,  1003 , and  1005 . 
     FIG. 11 illustrates a composite fabric  1100  using fabric layer  1141  with segmented expandable bladders  1101 - 1104  attached with fabric loops  1105 - 1108 . In this embodiment, inflation tube couplings  1120 - 1123  are used to couple the segmented expandable bladders  1101 - 1104  in a series connection. The inflation tube couplings  1120 - 1123  have corresponding flexible sections  1110 - 1113  that facilitate bending of the composite fabric  1100  along the width dimension (vertical in this illustration). The series connection of expandable bladders  1101 - 1104  is coupled via inflation tube  1154  and air valve  1152  to air source  1151 . Air source  1151  may be as simple as an air bulb used on blood pressure testing units. Controllable check valves are contained in the air valves  1150  and  1152  so that air may be correctly directed when inflating and deflating segmented expandable bladders  1101 - 1104 . Segmented expandable bladders  1101 - 1104  may be of the types detailed in FIG.  5  and explained earlier. Other embodiments of the present invention may not use inflation tube couplings  1120 - 1123 , rather expandable bladder  1101  is continuously threaded through fabric loops  1105 - 1108  and inflated and deflated as one long expandable bladder. 
     FIG. 12 is a flow diagram of method steps used in embodiments of the present invention. In step  1201 , one or more expandable bladders (e.g., expandable bladders  713 - 722 ) are attached to a fabric layer  761  defining fabric areas adjacent to expandable bladders (e.g., fabric areas  740  and  741 ). In step  1202 , selected expandable bladders from the one or more expandable bladders are inflated and deflated selectively covering and uncovering a selected fabric area (e.g., fabric area  741 ) with portions of the corresponding inflated and deflated expandable bladders (e.g., expandable bladders  716  and  717 ) so that the material characteristics (e.g., thermal insulation and moisture transmission) across the fabric area  741  of fabric layer  761  are varied. 
     FIGS. 13A,  13 B, and  13 C illustrate fabrications of fabric loops usable with embodiments of the present invention. The fabric loops are shown in edge views so that a corresponding width of the fabric loops is not visible. FIG. 13A illustrates a fabric loop  1302  which is formed by folding a length L of non-stretching fabric  1301  and joining at point  1303 . When fabric loop  1302  is expanded with an expandable bladder (not shown), it will assume a circular shape with a diameter De  1304  equal to L divided by the number π. FIG. 13B illustrates a stretchable fabric loop  1306  which may be formed with a length L 1  of stretchable material  1305  which has been folded and joined at  1307 . Stretching fabric loop  1306 , expands it to an expanded diameter De  1309 . FIG. 13C illustrates another fabric loop  1310  which is woven with a weaving or knitting machine to make fabric loop  1310  non-seamed. 
     FIGS. 14A and 14B are alternate perspective views showing a cross-section of fabric areas  132  and  332  and how they are affected by inflating their corresponding expandable bladders. FIG. 14A is a side view of composite fabric  100  showing non-stretching fabric loops  106  and  107 . Fabric loops  106  and  107  have deflated expandable bladders  102  and  103  which shows the portion of the cross section of fabric area  132  (see FIG. 1) of fabric  101  with an unmodified thermal insulation. Expandable bladders  102  and  103  selectively cover and uncover fabric area  132  to vary the thermal insulation across fabric area  132 . Arrow  1405  illustrates the heat transfer path through fabric layer  101 . The volume of air in fully inflated expandable bladders  102  and  103  completely blocks fabric area  132  of fabric  101  and generates a maximum thermal insulation for fabric area  132 . 
     FIG. 14B is a side view of composite fabric  300  showing a cross section of stretching fabric loops  301  and  302 . Fabric loops  301  and  302  have deflated expandable bladders  305  and  306  which shows the portion of fabric area  332  (see FIG. 3) of fabric layer  341  with an unmodified thermal insulation. Expandable bladders  305  and  306  selectively cover and uncover fabric area  332  to vary the thermal insulation across fabric area  332 . Arrow  1404  illustrates the heat transfer path through fabric layer  341 . The volume of air in fully inflated expandable bladders  305  and  306  completely blocks fabric area  332  of fabric  101  and generates a maximum thermal insulation for fabric area  332 . 
     FIG. 15 illustrates details of exemplary expandable bladder  504  that is designed to have a star shape when it collapses after evacuation. Expandable bladder  504  has a star shaped cross-section discussed earlier that may be formed by extruding a flexible material with controlled wall thickness&#39; (e.g.,  1505  and  1506 ). For example, expandable bladder  504  may be extruded into the shape  1503  at atmospheric pressure. If a bladder  504  is further evacuated, then it will compress to the shape illustrated by shape  1504 . As expandable bladder  504  is inflated, it may assume a shape  1502  and finally shape  1501  when fully inflated. Expandable bladder  504  may also be formed by folding and joining a flexible material to make a circular shape. Other types of expandable bladders that collapse to a certain minimum cross-section when deflated may also be used without departing from the scope of the present invention. 
     FIGS. 16A and 16B illustrate fabric products using a composite fabric made according to embodiments of the present invention. FIG. 16A illustrates a tent  1600  that has two triangular composite fabric sections  1601  and  1621 . The composite fabric sections  1601  and  1621  have expandable bladders with different bladder lengths across their surface. Composite fabric section  1601  has expandable bladders  1640 - 1649  attached with fabric loops (not shown) to its surface. Expandable bladders  1640 - 1649  are coupled in parallel with inflation tube  1604 . An air source  1602  (shown as a tire pump with adapter  1605 ) may be coupled to inflation tube  1604  via air valve  1603  and used to inflate expandable bladders  1640 - 1649  to selectively cover the area adjacent to and along the bladder lengths of the expandable bladders  1640 - 1649 . Air valve  1603  may be like any of a number of readily available air valves, for example an automobile tire air valve or a football air valve. Adapter  1605  is selected to be compatible with the particular air valve used. Area  1622  is an exemplary area adjacent to and along expandable bladders  1640  and  1641 . The expandable bladders (not numbered) on the surface of composite fabric section  1621  are coupled in parallel with inflation tube  1606  and use air valve  1607 . If composite fabric section  1601  needed the maximum thermal insulation, then expandable bladders  1640 - 1649  are completely inflated covering substantially all the area of composite fabric section  1601 . When expandable bladders  1640 - 1649  are fully inflated, composite fabric section  1601  would have its maximum thermal insulation. In other embodiments, each expandable bladder has its own air valve so that more control over the thermal insulation is possible. Expandable bladders  1640 - 1649  may be made and attached according to any of the embodiments illustrated in FIGS. 1,  2 ,  3 ,  4 ,  5 ,  6 ,  7 ,  8 ,  9 A- 9 C,  10 A- 10 C,  11 ,  13 ,  14 , and  15 . 
     FIG. 16B illustrates a side view of a fabric product in the form of a vest garment  1630  worn by an individual. Vest garment  1630  has expandable bladders  1608 - 1614  attached to its fabric surface with fabric loops (not shown). Vest garment  1630  has collar piece  1691  and arm opening  1618 . Expandable bladders  1608 - 1614  each have individual air valves, for example, air valves  1623  and  1620  on expandable bladders  1608  and  1609  respectively. Using individual air valves allows the thermal insulation of smaller areas of vest garment  1630  to be varied by expanding selected ones of expandable bladders  1608 - 1614 . In FIG. 16B, an air source  1617  is shown as an air bulb like one used on a blood pressure measurement apparatus. Adapter  1615  is compatible with the corresponding air valves used on expandable bladders  1608 - 1614 . Air control valves  1616  and  1625  are used to control when air is pumped into or evacuated from the expandable bladders  1608 - 1614  via hose  1624 . Expandable bladders  1608 - 1614  may be made and attached according to any of the embodiments illustrated in FIGS. 1,  2 ,  3 ,  4 ,  5 ,  6 ,  7 ,  8 ,  9 A- 9 C,  10 A- 10 C,  11 ,  13 ,  14 , and  15 . 
     Other fabric products that may be made with composite fabric according to embodiments of the present invention include but are not limited to an air mattress, shoes, a hat, and boots. Tent  1600  and vest garment  1630  illustrated in FIGS. 16A and 16B may have a second fabric layer attached and covering their corresponding expandable bladders for aesthetics and for additional protection of the expandable bladders. Also the expandable bladders in FIGS. 16A and 16B are shown on the outside of the fabric products for illustration purposes only. Expandable bladders  1640 - 1649  may be on the inside of tent  1600  and still be within the scope of the present invention. Likewise, expandable bladders  1608 - 1614  may be on the inside of vest garment  1630  and still be within the scope of the present invention.