Patent Publication Number: US-2006008616-A1

Title: Insulation material including extensible mesh material from fibrous material

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
      This application is a continuation-in-part of U.S. patent application Ser. No. 10/889,442 filed Jul. 12, 2004, the content of which is incorporated by reference in its entirety. 
    
    
     TECHNICAL FIELD AND INDUSTRIAL APPLICABILITY OF THE INVENTION  
      The present invention relates generally to a web of insulation that is configured to provide a series of openings in an expanded web, where the openings within the extended web are filled with insulation to provide a batt or panel of thermal or acoustical insulation. More specifically, the present invention relates to an insulation filled extended fibrous web that is suitable for use as thermal or acoustical insulation in a building structure, as a partition or panel, or as thermal or acoustical insulation in a motor vehicle.  
     BACKGROUND OF THE INVENTION  
      Perforated nonwoven fabrics of fibrous material are well known in the art. Representative examples include U.S. Pat. No. 5,714,107 to Levy et al.; U.S. Pat. No. 4,615,671 to Bernal; and U.S. Pat. No. 3,864,198 to Jackson. In each of these prior art patents, the fibrous material is slit or cut and then subjected to stretching to provide a honeycomb web or open cell structure.  
      Unfortunately, stretching the material to form the honeycomb or open cellular structure leads to the tearing of a significant number of the fiber-to-fiber bonds thereby reducing the strength and integrity of the resulting material. Further, the friability of the material is also increased by the tearing of so many bonds. Thus, erection of the honeycomb web or cellular material in accordance with prior art methods leads to significant detrimental results.  
      The present invention relates to an insulation material that includes a honeycomb web precursor and a method of producing an insulation filled honeycomb web where the precursor is erected by folding rather than stretching. Accordingly, the resulting product has improved fiber-to-fiber bond integrity and exhibits reduced friability when compared to prior art cellular structures.  
     SUMMARY OF THE INVENTION  
      In accordance with the purposes of the present invention as described herein, an insulation batt that includes an extensible honeycomb web is provided. The honeycomb web precursor includes a body of fibrous material with a series of slits that extend between opposed surfaces of the body of fibrous material. The web may then be filled with an appropriate insulation material to form the insulation material of the present invention. Advantageously, the body is extensible into a web or honeycomb construction primarily by bending or flexing the fibers rather than extending the fibers or the axially displacing the fibers.  
      More specifically, the fibrous body may include thermoplastic fibers, thermosetting fibers, glass fibers, metallic fibers, ceramic fibers or combinations thereof. The fibers may be single component, or multi-component. The multi-component fibers may be sheath core, side by side, islands in the sea or any other suitable multi-component configuration. In accordance with one aspect of the present invention, the honeycomb web may be formed of any suitable fiber including but not limited to polyolefin fibers, polyamide fibers, polyester fibers, polypropylene fibers, polyvinyl chloride fibers, polyethylene fibers, nylon fibers, rayon fibers, polyethylene terephthalate fibers, polyvinyl acetate fibers, polybutylene terephthalate fibers, melamine fibers, acrylic fibers, visil fibers, aramid fibers, glass fibers, metal fibers, basalt fibers, mineral fibers, carbon fibers, graphite fibers, cotton fibers, sisal fibers, and mixtures thereof.  
      The fibrous insulation that fills the interstices of the honeycomb web may be formed of any suitable fiber including, but not limited to polyolefin fibers, polyamide fibers, polyester fibers, polypropylene fibers, polyvinyl chloride fibers, polyethylene fibers, nylon fibers, rayon fibers, polyethylene terephthalate fibers, polyvinyl acetate fibers, polybutylene terephthalate fibers, melamine fibers, acrylic fibers, visil fibers, aramid fibers, loosefill glass fibers, metal fibers, basalt fibers, mineral fibers, carbon fibers, graphite fibers, cotton fibers, sisal fibers, and mixtures thereof.  
      The fibrous body typically includes both inexpansible portions at the peripheral edges and a medial expansible portion. The inexpansible portion is substantially continuous and the expansible portion may include a series of slits. In one embodiment, the inexpansible and expansible portions alternate across the body. In another embodiment the inexpansible portion forms the lateral edges of the fibrous body while the expansible portion forms the interior of the fibrous body.  
      Still more specifically describing the invention, the series of branched slits at least partially nest within one another. In one possible embodiment, each of the branched slits is substantially Y-shaped. Adjacent branched slits define an expansion rib. Each expansion rib includes a first segment and a second segment. The first segment is connected to the second segment by a first flexible hinge. The first segment is connected to one of the inexpansible portions by a second flexible hinge and the second segment is connected to another of the inexpansible portions by a third flexible hinge.  
      In accordance with one aspect of the present invention, a honeycomb web precursor is provided that includes a body of fibrous material that includes alternating rows of slits. In another aspect of the invention, the slits may intersect with openings having extension slits to define a four-way flexible hinge at a convergence of adjacent slits and the openings such that when the fibrous body is expanded, a series of interstitial openings is formed.  
      In accordance with yet another aspect of the present invention, a method is provided for producing a honeycomb web of fibrous material, subsequently expanding the web to form interstitial spaces and filling those interstices with fibrous insulation. The method includes making a series of slits in a body of fibrous material to define multiple ribs such that the body may be expanded. The ribs may then be expanded to form a honeycomb web defining open interstices between the ribs. The honeycomb web may then be filled with an insulation material having desired thermal insulating, acoustical insulating and/or structural properties. The insulation panel may then be fixed in the expanded state by thermally bonding the thermoplastic fibers, setting a binder in insulation material or any other suitable method of adhering the fibers one to another. The panel may then be sealed by the application of a facer material to one or preferably both sides of the panel.  
      The expanding or erecting of the honeycomb web is preferably achieved by bending or flexing the fibers rather than by stretching the body, by extending the fibers, or axially displacing the fibers. Accordingly, the integrity of fiber-to-fiber bonds is maintained for maximum material strength and to minimize the friability of the resulting erected structure.  
      A motor vehicle panel of a honeycomb web of fibrous material that includes a series of geometric shaped openings may be formed. A partition of a honeycomb web of fibrous material that includes a series of geometric shaped openings with a facer attached to one side may also be formed. A second facer may be attached to an opposing surface to provide a sandwiched structure with the web positioned between the first and second facers. In accordance with yet another aspect of the present invention, one or both of the facers may be decorative facers. The facers may be formed of any suitable material, such as, natural or polymeric fibrous material, foils, paper, fiberglass mats, or polymer sheets or films such as ester vinyl acetate, polyvinyl chloride, rubber materials and highly filled sheets or films. The facer may also include a reinforced web. The second facing layer may then be connected to the second face. That second facing layer may be constructed from materials similar to those of the first facing layer. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The accompanying drawings incorporated in and forming a part of the specification, illustrate several aspects of the present invention and together with the description serve to explain certain principles of the invention. In the drawings:  
       FIGS. 1   a  and  1   b  are top plan views respectively illustrating a first embodiment of the honeycomb web precursor and the folded or erected honeycomb web of a first embodiment of the present invention;  
       FIGS. 2   a  and  2   b  are top plan views illustrating, respectively, an unerected honeycomb web precursor and an erected honeycomb web of a second embodiment of the present invention;  
       FIG. 3  is a cross sectional view illustrating another possible embodiment of the present invention where the spaces, openings or interstices of the web material are filled with a material selected for its insulating or other properties;  
       FIG. 4  is yet another embodiment of the present invention where the honeycomb web includes a first facing layer and an insulation material;  
       FIG. 5  is a schematic side elevation view illustrating the insulation panel of the present invention including flanges; and  
       FIG. 6  is yet another alternative embodiment where the honeycomb web includes opposing facing layers. 
    
    
      Reference will now be made in detail to the present preferred embodiment of the invention, an example of which is illustrated in the accompanying drawings.  
     DETAILED DESCRIPTION AND PREFERRED EMBODIMENTS OF THE INVENTION  
      Reference is now made to  FIG. 1   a  showing a honeycomb web precursor  10  of the present invention. The honeycomb web precursor  10  is formed from a body of fibrous material. Suitable fibrous materials include non-woven materials formed of thermoplastic or thermoset fibers, glass fibers, metal fibers, basalt fibers, mineral fibers, carbon fibers, graphite fibers or natural fibers such as cotton, kenaf, and sisal or combinations thereof. Multi-component fibers may also be utilized. Specific examples of polymeric fibers that may be utilized to construct the body include polyolefin fibers, polyamide fibers, polyester fibers, polypropylene fibers, polyvinyl chloride fibers, polyethylene fibers, nylon fibers, rayon fibers, polyethylene terephthalate fibers, polyvinyl acetate fibers, polybutylene terephthalate fibers, melamine fibers, acrylic fibers, visil fibers, aramid fibers and any mixtures thereof. Any suitable materials may be used. Typically, the fibers in the body have a diameter between about 5 and 50 microns and a length between about 12.6 and 75.6 mm.  
      As illustrated in  FIG. 1   a , the honeycomb web precursor  10  may include alternating inexpansible portions  12  and expansible portions  14 . The inexpansible portions are substantially continuous, elongated strips whereas the expansible portions are a series of branched slits  16  that extend completely through the body of the precursor  10 . As illustrated, each branched slit is substantially Y shaped and the series of branched slits at least partially nest with one another. Any suitable pattern of cuts which allows the elongation of the web may be employed. As illustrated in  FIG. 2   a , the inexpansible portions are optional.  
      As further illustrated in  FIGS. 1   a  and  1   b , adjacent branched slits  16  define an expansion rib  18 . Each expansion rib  18  includes a first segment  20  and a second segment  22 . The first segment  20  is connected end-to-end with the second segment  22  by a first flexible hinge  24 . The opposite end of the first segment  20  is connected to an inexpansible portion  12  of the precursor  10  by a second flexible hinge  26 . Similarly, a third flexible hinge  28  connects the opposite end of the second segment  22  to another, different inexpansible portion  12 . It is also possible to form a honeycomb web precursor  10  that includes a single expansible portion  14  between lateral inexpansible portions. This embodiment is especially useful in creating a web for subsequent processing in for example a die cutting operation.  
       FIG. 1   b  shows an expanded honeycomb body  30  and the erected expansion ribs  18 . More specifically, each of the expansion ribs  18  is folded along first, second and third flexible hinges  24 ,  26 ,  28  so that inexpansible portions  12  are separated and the expansion ribs are erected so as to extend between adjacent inexpansible portions  12 . As a result, a series of interstitial openings  32  are provided between adjacent expansion ribs  18  and inexpansible portions  12 . Depending upon the size of the branched slits  16  provided in the expansible portions  14  of the honeycomb web precursor  10 , the area covered by the geometric pattern of the erected honeycomb web  30  compared to the original area of the honeycomb web precursor  10  can be an increase of about 110 to 500%.  
      The erected honeycomb web  30  may then be filled with an insulation material  54 . An erected honeycomb web  30  filled with thermoplastic fibers may be heat treated above the softening point of the material and then cooled in order to thermally set the panel in the erected shape. An erected honeycomb web  30  filled with an uncured bindered material may be heated to cure the binder to set the panel in the erected shape. An erected honeycomb web  30  filled with precured or unbonded fibers may then be treated with an adhesive such as thermoset resin, thermoplastic powder, epoxy or chemical glue and heated to set the panel.  
      As seen in  FIG. 4 , a facing layer  34  may be adhered to a first face  36  of the erected honeycomb web  30 . In yet another embodiment, as shown in  FIG. 5 , a second facing layer  38  may be adhered to a second facing  40  of the erected honeycomb web  30 . In either of these embodiments the facing layers  34 ,  38  are sufficiently rigid to hold the expansion ribs  18  in the expanded or erected position and maintain the insulation material in the interstices  32  of the honeycomb web  30 . The first and second facing layers  34 ,  38  may be formed of any suitable material, for example, natural or polymeric fibrous materials, foils, paper, fiberglass mats, or polymer sheets or films such as ester vinyl acetate, polyvinyl chloride, nylon, rubber and highly filled sheets or films. The facer may also include a reinforced web. It is often preferred to use a vapor permeable facing layer  34  on one side of the panel while using a vapor impermeable facing layer  38  on the opposite side of the panel. One or both facing layers  34 ,  38  may extend beyond the peripheral edges of the panel  30  to form flanges  34   a ,  38   a  that may be used to secure the panel  30  to the item to be insulated, for example to the studs of a wall cavity in a residential structure.  
      Yet another alternative embodiment is illustrated in  FIGS. 2   a  and  2   b . In this embodiment, a honeycomb web precursor  10 ′ is formed of a fibrous material. In this alternative embodiment of the invention, alternating rows of straight slits  42  and openings  44  with extension slits  46  define a four-way flexible hinge  48  at a convergence of slits  42 ,  46  and openings  44 . Similar to the embodiment shown in  FIG. 1   a , the embodiment shown in  FIG. 2   a  may be erected by folding the honeycomb web precursor  10 ′ about the four-way flexible hinges  48  provided at the convergence of adjacent straight slits  42  and openings  44  and the additional flexible hinges  50  provided at opposing corners of alternating openings  44  that do not define four-way flexible hinges  48 .  
      The erected honeycomb web  52  of the embodiment illustrated in  FIG. 2   b  may be held in the erected position by thermally setting the material, prior to the insertion of insulation  54  and the application of any facing layers. An exemplary method of in-line production of the insulative panel of the present invention is schematically illustrated in  FIG. 6 .  
      The body of fibrous material  60  may be fed from a roll or directly from a forming station through a rotary die cutter  70  that cuts the nested, branched slits  16  in the expansible portions of the precursor  10 . If desired, the precursor  10  may then be advanced through a series of spreader rolls  80  that expand the precursor by folding the expansion ribs  18  open about the hinges  24 ,  26 ,  28 . The honeycomb web  30  may then be advanced through a filling, setting or laminating device  90 . The device  90  typically inserts the insulation material  54  into the interstices and may include a thermal oven or a facing applicator. If an adhesive or binder is used to set the panel  30 , the adhesive may be applied during the manufacture of the fibrous material  60  or insulation material, by application of adhesive to the fibrous material  60 , the precursor  10 , or the insulation panel  30  prior to entering the setting device  90 .  
      In any embodiment of the present invention, the interstitial openings  32  may simply function as air spaces. As shown in  FIGS. 4 and 5 , the interstices  32  may be filled with fibrous material  54  and sealed with a facer on one or both sides. Suitable insulation materials include bonded loosefill, such Advanced ThermaCube Plus (available from Owens Corning of Toledo, Ohio), unbonded loosefill insulation, such as ProPink (available form Owens Corning of Toledo, Ohio), and cubes, nodules or bundles of fibers of any suitable fibrous material. As shown in  FIG. 5 , the filling material  54  may be sealed within the interstices  32  by providing a facing layer  34 ,  38  over each face  36 ,  40  of the honeycomb webs  30 ,  52 .  
      The insulation panel  30  has myriad applications including: a batt of thermal or acoustical insulation for use in residential structures or a partition such as a room partition or other structural panel such as a building panel. The insulation panel  30  may be used as an acoustical decoupler, as a stiffener or as a spacer between two or more fibrous webs to be subsequently processed. According to the present invention, the process and product may be utilized to reduce materials used in constructing a panel, partition or the like. The honeycomb web of the present invention reduces both the production costs and the weight of the final product without any significant compromise in product strength.  
      The insulation panel  30  may also be useful as an acoustical and thermal insulator in a motor vehicle. Some other potential applications in the automotive industry include, but are not limited to, under carpet applications, heat shields, acoustical decouplers for engine sides and interior materials and as a filler material. Potential non-automotive applications for the insulation panel  30  include the appliance industry where the material may be used as a dishwasher blanket, range insulator, oven insulation, clothes washer insulator and clothes dryer insulator, and as acoustical filler materials for wall panels and ceiling tiles.  
      The foregoing description of the preferred embodiment of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. For example, while a rotary die cutter  65  is described and illustrated for cutting the branched slits  16 ; other devices/methods could be utilized. Such devices include, but are not limited to, cutting by water jet, laser and/or die rule.  
      The embodiments chosen and described provide illustrations of the principles of the invention and practical applications to enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular uses contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally and equitably entitled. The drawings and preferred embodiments do not and are not intended to limit the ordinary meaning of the claims and their fair and broad interpretation in any way.