Abstract:
A material comprises a cover layer and a porous material layer. The cover layer may include a rigid, semi-rigid or flexible material and the porous spacer material layer may include a reticulated foam, nonwoven textile, or a spacer fabric. The material is configured to have a high air flow rate upon an application of a pressure, and good compactability.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS  
       [0001]     This application is a continuation-in-part of application Ser. No. 10/829,397, filed Apr. 22, 2004, incorporated herein by reference in its entirety. 
     
    
     BACKGROUND  
       [0002]     The present invention relates to a spacer fabric.  
         [0003]     Certain conventional fabrics include a padding or porous layer covered by an outer layer. The underlying padding or porous layer is typically sewn to the outer layer. The outer layer in the conventional sewn assembly may pucker or have other surface deformations resulting from the sewn seams. Additionally, in certain situations, pockets or gaps may be formed between the padding and outer layers. These problems create an undesirable appearance and may decrease the value of a seat or the object utilizing the sewn fabric. The puckering and air pockets may also create an uncomfortable surface when contacted by a person sitting or leaning against the sewn fabric.  
         [0004]     The porous or padding layer may be a spacer fabric. The conventional covered spacer fabrics generally result in increased costs for the manufacturer. Rolls or cut pieces of the spacer fabric are produced, pre-cut, and shipped to an assembly plant. After shipment, the spacer fabric tends to lose its dimensions. As a result, the process of sewing a precut outer layer to the spacer fabric is difficult and time-consuming. Another drawback of the conventional spacer fabric is that the edges of the conventional fabric fray and lack dimensional stability.  
         [0005]     These covered spacer fabrics have many uses such as, for example, seats, home furnishings, and shoes. Conventional spacer fabrics incorporated in seats may be found, for example, in DE 19931193 (hereby incorporated by reference herein in its entirety).  
         [0006]     The spacer fabric is typically a padding or ventilation layer. Seats generally use spacer fabrics to cool or warm an occupant or remove perspiration. However, typical seats in spacer fabrics wear quickly and may chill or overheat an occupant due to improper air flow.  
         [0007]     Spacer fabrics offer several advantages over other padding or ventilation layers such as, for example, foam. First, spacer fabrics are formed from textile fibers and filaments and many textile fiber and filamentary materials are recyclable. Thus, the use of spacer fabrics as a cushioning material overcomes the inability of foams to be recycled and the attendant problems associated with disposal of such materials. Also, spacer fabrics offer substantially enhanced air and moisture permeability over foams, which make such fabrics more desirable than foam materials for use in automotive and marine applications as well as home furnishing applications.  
         [0008]     As described above, current textile technology includes spacer fabric materials with sewn on material coverings. Spacer fabrics covered with a sewn on material characteristically have the tendency for the opposing covering and spacer structures to shift and move in parallel with respect to one another. Moreover, there are inherent difficulties in mating a rigid or semi-rigid surface material (e.g. leather) with a non-rigid spacer material through a sewing process. One problem is that the dimensions of the cut pieces of spacer material tend to change size after cutting, typically shrinking in size. As a result, when the cut part of rigid or semi-rigid material is sewn around the perimeter to the cut piece of spacer fabric, the change in dimensions of the spacer material cause puckering and creasing in the rigid or semi-rigid cover layer. A large number of the sewn components have this problem. Present attempts to solve this specific problem have focused on using a more rigid, higher denier monofilament in the spacer fabric to improve the sewing performance and have not been successful. The use of a significantly heavier denier monofilament produces an uncomfortable fabric.  
         [0009]     Other problems encountered in joining cut pieces of spacer fabric to cut pieces of a cover material include rough, jagged edges; fraying and shedding of monofilament pile; missing or misplaced notches (to guide the sewer); during sewing, the sewing needle and presser foot snag in the spacer fabric; and sewing “run off” or “raw edge” where the stitches of the joining seam do not grip the spacer fabric. The primary causes of these problems are inconsistent part dimensionality, inherent elasticity of the fabric, and jostling during transit.  
         [0010]     An additional problem associated with such conventional fabrics are that they collapse under minimal loading. Furthermore, conventional fabrics such as reticulated foam lack the ability to transport air through the material at a sufficiently high rate to cool or warm the material.  
       SUMMARY OF THE INVENTION  
       [0011]     According to one embodiment, a material is provided. The material comprises a first fabric layer; a second fabric layer; and a pile layer extending between the first fabric layer and the second fabric layer. The pile layer is configured so that when the material is subjected to air pressure of 200 mBar, the air flow rate through the pile layer is in the range of approximately 80 to 300 cfm.  
         [0012]     According to another embodiment, a material is provided that includes a porous material layer including a plurality of fibers extending between a pair of fabric layers. Each of the fibers has a tenacity in the range of approximately 40 to 50 cN/tex.  
         [0013]     According to another embodiment, a material is provided that includes a porous material layer including a plurality of fibers extending between a pair of fabric layers. Each of the fibers has a diameter in the range of approximately 0.07 to 0.1 1 mm.  
         [0014]     According to another embodiment, a material is provided that comprises a first fabric layer; a second fabric layer; and a pile layer extending between the first fabric layer and the second fabric layer. The material is configured to have a specific compactability in the range of 35 to 100 cm 3 .  
         [0015]     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only, and are not restrictive of the invention as claimed. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]     These and other features, aspects, and advantages of the present invention will become apparent from the following description, appended claims, and the accompanying exemplary embodiments shown in the drawings, which are briefly described below.  
         [0017]      FIG. 1  is a sectional view of a material according to an embodiment of the present invention.  
         [0018]      FIG. 2  is a sectional view of a porous material according to an embodiment of the present invention.  
         [0019]      FIG. 3  is a sectional view of the material according to  FIG. 1 .  
         [0020]      FIG. 4  is a sectional view of a seat according to an embodiment of the present invention.  
         [0021]      FIG. 5  is a sectional view of the material according to an embodiment of the present invention.  
         [0022]      FIG. 6  is a top-side view of the spacer fabric according to another embodiment of the present invention.  
         [0023]      FIG. 7  is an underside view of the spacer fabric according to  FIG. 6 . 
     
    
     DETAILED DESCRIPTION  
       [0024]     Hereinafter, embodiments of the present invention will be described with reference to the attached drawings.  
         [0025]     According to an embodiment of the present invention, a material  10  is provided. The material  10  includes a porous material layer  15 . Additionally, as shown in  FIG. 5 , the material  10  can also include a cover layer  30 . The cover layer  30  may be porous and may include a poly-vinyl chloride polymer coated material, leather, body cloth fabric, a thermoplastic olefin coated material, a polyurethane coated material, or any other suitable material. The porous material layer  15  may be a reticulated foam, a nonwoven textile, or preferably a spacer fabric. A material  10 , according to an embodiment of the invention includes a cover layer  30  and a spacer fabric  20 . The spacer fabric  20  comprises a first  22  and second fabric  26  layer, and a pile layer  24 . The cover layer  30  is laminated onto the spacer fabric  20 .  
         [0026]     A seat, according to another embodiment of the invention, includes a cover layer  30 , and a porous material  15 . The porous material  15  is positioned under the cover layer  30  and the cover layer  30  is laminated on the porous material  15 .  
         [0027]     A material  10 , according to another embodiment of the present invention, includes a spacer fabric  20  covered by a cover layer  30 . The cover layer  30  is laminated to the spacer fabric  20  so that the top surface of the material  10  is substantially smooth.  
         [0028]     According to an alternative embodiment of the present invention, the porous material layer  15  may comprise a spacer fabric  20 . The spacer fabric  20 , as shown in  FIGS. 1 and 2 , may include a first fabric layer  22 , a second fabric layer  26  and a pile layer  24  which connects the first  22  and second  26  fabric layers. The fabric layers  22 ,  26  are made of a knitted material. The pile layer  26  is composed of 100% by weight of monofilament yarn. The spacer fabric layer  20  may be produced on a multi-guide bar, double needle bar, Raschel type knitting machine, or by any other suitable loom or knitting machine.  
         [0029]     The spacer fabric layer  20  is configured to allow air to flow through the material and remove or evaporate moisture from an outer surface. The cover layer  30  is attached to the first fabric layer  22 . The cover layer  30  may be a continuous material and include perforations  32  which allow for fluid (i.e. air, moisture and / or climate controlled forced air) to flow through the layer. The perforations shown  32  in the drawings are exemplary only and may be in different locations or sizes.  
         [0030]     The spacer fabric  20  may be approximately 4 to 60 mm in thickness. According to another embodiment of the invention, the thickness of the spacer fabric may be 6 to 30 mm. Preferably, the thickness of the spacer fabric  20  is about 8 to about 12 mm. The denier of the pile yarn may be approximately 30 to 1200 denier. According to another embodiment of the invention, the denier of the pile yarn may be 100 to 900. Preferably, the denier of the pile yarn is about 150 to about 600.  
         [0031]     The first fabric layer  22  of the spacer fabric  20  may be of any configuration, but is preferably a close-knit arrangement. The second fabric layer  26  is preferably a open mesh, honeycomb surface structure, but may be configured to be any suitable structure. The denier of the yarn in the first and second fabric layers may be 40 to 1200. According to another embodiment of the invention, the denier of the yarn in the first and second fabric layers may be 100 to 900. Preferably, the denier of the yarn in the first and second fabric layers is about 150 to about 600. The denier of the yarn in the first layer may differ from the denier of the yarn in the second layer.  
         [0032]     The spacer fabric  20  is an air permeable fabric. The spacer fabric  20  may also increase the cushioning feel to an occupant or user of the fabric and may repel and/or absorb moisture on one or both sides-of the fabric  20 . The spacer fabric  20  may be configured so the first fabric layer  22  has an air permeability different from the air permeability of the second fabric layer  26 .  
         [0033]     According to an embodiment, the second fabric layer  26  includes a first portion  23  for air supply or air removal which is made with the greatest possible air permeability (shown in  FIG. 7 ). The first fabric layer  22  may include a second portion  25  that is made with reduced air permeability, as shown in  FIG. 6 . The second portion  25  is aligned opposite the first portion  23 . According to an embodiment of the invention, both the first 23 and second 25 portions are generally circular. The second portion  25  is adjoined by a third portion  29  which has increased air permeability as the distance increases from the second portion  23 . The third portion  29  and adjacent portions  29   a  are generally annular and continue to increase in air permeability the farther from the second portion  23 . As shown in  FIG. 7 , the second fabric layer  26  may include a fourth portion  27  that decreases in air permeability and is generally an annular shape around the first portion  23 . The fourth portion  27  and adjacent portions  27   a  decrease in air permeability the farther from the first portion  23 . The portions  23 ,  25 ,  27 ,  29  may be defined by cut edges. The different air permeabilities allow air flow to pass through the second fabric layer  26 , at or near the first portion  23  and pass through the pile  24  and first fabric layer  22  with approximately uniform distribution of the air flow. Of course, as will be recognized by those skilled in the art, the air flow direction may be reversed and/or the location of the portions  23 ,  25 ,  27 ,  29  may be switched in order to have equal flow distribution with a change in direction of flow. The first  23  and second portions  25  may also be any other configuration or shape suitable for air circulation such as, for example, rectangular. As will be appreciated by those skilled in the art, any suitable type of spacer fabric may be used.  
         [0034]     According to an embodiment, the second fabric layer  26  is configured to be adjacent an air circulation system  50 , as shown in  FIG. 2 . The air circulation system  50  is not part of the spacer fabric  20 , but is a separate system. The air flow system  50  may comprise electric fans  52 , such as, for example, the system found in U.S. Pat. Nos. 5,626,021 or RE 38,128 (both patents are hereby incorporated by reference herein in their entirety). Of course, any other suitable air circulation system  50  may be used. The air flow system  50  may cool or heat the fabric  20  or the object attached to the fabric  20 , such as a seat, bed, backpack, or any other suitable object. The air flow system  50  may force air through the fabric and blow the air through the second fabric layer  26 , distributed through the pile layer  24  and out and through the first fabric layer  22 .  
         [0035]     As mentioned above, the porous material  15  may comprise a reticulated foam or a nonwoven textile. The cover layer  30  attaches to one side of the porous material  15 . The cover layer  30  is attached to a side of the porous material layer  15  by lamination. The cover layer  30  may be laminated onto the porous material layer  15  by any suitable method such as, for example, thermoplastic laminates, thermoset processes, cold laminating, or a UV curable adhesion system.  
         [0036]     In the case of the porous material layer  15  comprising a spacer fabric  20 , the cover layer  30  is attached to the first fabric layer  22  on a side adjacent to the pile layer  24 . The cover layer  30  may be attached to the first fabric layer  22  by any suitable mechanism, such as by sewn seams, fasteners, adhesives, etc.  
         [0037]     In one embodiment, a laminate  60  is applied to and coated on an underside of the cover layer fabric  30  which is then positioned on the first fabric layer  22 . The material  10  may then be held under weight for approximately twenty-four hours to properly seal the cover layer  30  to the first fabric layer  22  and, thus, the spacer fabric  20 . The same basic process may be employed for laminating the cover layer  30  to other embodiments of the porous material layer  15 .  
         [0038]     According to an embodiment of the invention, the laminate  60  may be formed by the use of a solvent born, flame retardant polyurethane adhesive, or any other suitable adhesive. According to one embodiment of the present invention, the laminate  60  may be applied to the cover layer  30  by hot melt spun adhesive or by spraying the adhesion onto, the underside of the cover layer  30  by a spray nozzle or oscillating disk. The spray nozzle or oscillating-disk passes along the length of the material to coat the cover layer  30  and then the cover layer  30  is pressed onto the porous material layer  15 . Before a laminate  60  is applied to the cover layer  30 , the cover layer  30  and porous material layer  15  is heat set at approximately 400 degrees Fahrenheit.  
         [0039]     According to another embodiment, the cover layer  30  may be further secured to the porous material layer  15  by a variety of different welding processes, i.e., a radio frequency (RF) welding process, thermal heat sealing, ultrasound and dielectric sealing. For example, the materials can be RF welded along the perimeter of the material  10 . The RF weld may be applied with utilizing a die. The material  10  may also be sewn along the perimeter after the cover layer  30  is laminated to the porous material layer  15 .  
         [0040]     The material  10  effectively simulates the compressibility and resiliency of conventional spacer fabric and plastic foam materials such as polyurethane. In addition, the material  10  provides wear reduction, improved seam strength, reduced edge fraying and ease of production.  
         [0041]     The material  10  has improved wear characteristics. The cover layer  30  has less mobility in comparison to the porous material layer  15 . In other words, according to the present invention, there is less relative movement between the cover layer  30  and the porous material layer  15 . The cover layer  30  does not slide relative to the adjoining porous material layer  15 . Accordingly, the life of the fabric  10  is increased. Furthermore, the seam strength of the fabric  10 , as may be tested by a needle pullout test, is increased due to the attachment of the cover layer  30  to the porous material layer  20 .  
         [0042]     According to another embodiment, as shown in  FIG. 4 , a seat  40  for an automobile, watercraft, or any other type of seat  40  is provided. The seat  40  may include a seat back  44  and/or a seat bottom  46 . The seat  40  includes a cover layer  30  which is integrated onto a surface of the seat back  44  and/or seat bottom  46  adjacent to an occupant (not shown). A porous material is positioned adjacent to the cover layer  30  on a side of the cover layer  30  opposite the occupant. The porous material may be a reticulated foam, a nonwoven textile, or a spacer fabric and attached onto the cover layer  30 . According to  FIG. 4 , a spacer fabric  20  is shown. The spacer fabric  20  is similar to that described above and includes a first fabric layer  22 , a second fabric layer  26  and a pile layer  24 . The use of the material  10  including a cover layer overlying a porous material layer for the seat covering allows for air flow and/or removal or evaporation of moisture from the exposed surface of the seat bottom and back adjacent to an occupant.  
         [0043]     The,seat  40 , according to an embodiment of the invention, may further include an air circulation flow device  50 . The air flow device  50  may include fans  52 . The fans  52  are shown in  FIG. 4  in exemplary locations only and may be positioned in various, suitable locations. The air flow device  50  may be the Amerigon climate control system, for example the system disclosed in U.S. Pat. Nos. 5,626,021 or RE 38,128, or any other suitable air flow/removal system.  
         [0044]     It is to be understood that any suitable spacer fabric may be used as the porous material in the material  10  and the seat  40 . In addition, different combinations of cover layers  30  and ventilated materials  20  may be used for the material  10  and seat.  
         [0045]     According to an embodiment of the present invention, the material  10  exhibits many improved characteristics. The material  10  resists compression and collapse. As a result, air flow through the material  10  can be maintained over a wide range of loadings. When the material is used as a seating surface, the improved compression and bend performance may prevent or reduce the collapse of the seating surface into the underlying air manifolds thereby preventing patterning in these passages and preserving the air transport capabilities of the material. Furthermore, when used in combination with a forced air system, the system noise can be reduced due to a reduction in back pressure on the system fan caused by constricted air flow.  
         [0046]     The improved characteristics of the present invention, may be measured and specified in a number of different ways. For example, according to an embodiment of the present invention, the material  10  provides reduced compression for a given loading applied perpendicular to the surface of the material. For example, according to an embodiment of the invention, the material  10  exhibits less than a 15 percent reduction of thickness in response to a load of 150 Newtons. Further by way of example, the material  10  exhibits less than a 10 percent reduction of thickness in response to a load of 100 Newtons.  
         [0047]     For example, a specific sample of laminated space fabric according to an embodiment of the present invention has an unloaded thickness of 10 mm. When a load is applied to the sample in a direction generally perpendicular to the attachment side surface of the material  10 , the thickness of the material gradually reduces at a generally linear rate. The thickness of the fabric is reduced from about 9 mm to about 8 mm as the load increases from 25 to 175 Newtons. More specifically, for the 10 mm thick sample of the material  10  according to an embodiment of the present invention, the material is configured to resist a reduction of thickness greater than 20 percent for applied loads less than about 150 Newtons.  
         [0048]     The material  10 , according to another embodiment of the invention, is configured to exhibit Hookean behavior. The material  10  can offer a linear response to loading over a tested range. On the contrary, other conventional materials display asymptotic behavior and will undergo no further compression; resulting in incompressible solids.  
         [0049]     According to an embodiment of the present invention, the air flow through the fabric in two dimensions (i.e, parallel and perpendicular to the laminated surface) may be improved.  
         [0050]     A material  10  according to an embodiment of the present invention was tested to determine the ability of the material to allow airflow while under load. Accordingly, as shown in Table 1 below, a material was subjected to a varying amount of load to produce a variety of different thicknesses of material. The airflow through the material was determined for a constant air pressure (200 mBar). The required force to be applied to the material  10  to produce the displacement or reducing in thickness, could be determined according to the Hook&#39;s constant for the material. Due to the improved configuration, the material  10  according to an embodiment of the present invention will maintain air passages at loadings far in excess of those offered by the other conventional materials. As can be seen in Table 1, the exemplary material  10  is configured to have an air flow in the range of 80 to 275 CFM under pressure in the range of about 40 to about 200 Pa, when compressed to a thickness of 7.11 mm. Alternatively, the exemplary material  10  allows for an air flow in range of approximately 80 to about 210, under pressure in the range of about 40 to 200 Pa when compressed to a thickness of 6.1 mm. 
         
 
         [0051]     As shown in Table 1, characteristics for exemplary material compressed to both 4.8 mm and 3.8 mm thicknesses are disclosed. For the 10 mm thick exemplary material  10  used to obtain the results of Table 1, it should be noted that for an approximately 50 percent reduction of thickness of the material there is only an approximately 50 percent reduction in air flow from approximately 250 cfm to 130 cfm at an applied pressure of 200 mBar.  
         [0052]     The improved characteristics of the present invention may be measured in an alternative format. For example, when an exemplary laminated space fabric is placed under a defined pressure of approximately 200 mBar, the material  10  will have a reduction in thickness as determined by Hook&#39;s constant for the material. As a result, if a constant displacement is applied, the exemplary material  10  will undergo a higher state of force compared to other, conventional laminated fabrics.  
         [0053]     Thus, an advantage of the material  10  is that it allows air passage at force loadings far in excess of those offered by other, conventional materials. For example, under a load of 200 mBar, the air flow of the material  10  ranges from approximately 275 to 75 CFM, while under a loading of approximately 50 to 300 Lb force. In comparison, a conventional reticulated foam material ranges from approximately 160 to 50 CFM under a loading of 0 to 50 Lb force, as shown in Table 2. 
         
 
         [0054]     As mentioned above, the material  10  according to an embodiment of the present invention, exhibits increased resistance to compression. Therefore, as shown in Table 3, the amount of force applied to the fabric to achieve a 70 percent reduction in thickness is significantly greater for a material according to the present invention than for a conventional foam or spacer material. Table 3 discloses the amount of force required to achieve a 70% reduction in thickness for a fabric of a given thickness. For example, for fabrics in a thickness range of 20 to 40 mm, the material  10  would need to be subject to approximately 90 to 110 pounds force in order to obtain the 70% reduction. 
         
 
         [0055]     In another embodiment, the pile layer  24  is configured to have an air flow rate of 200 to 300 cfm while the material  10  is compressed to the point of maintaining 40 % original loft. At this air flow rate, the material  10  is under a pressure of approximately 200 mBar. More specifically, the flow rate is in the range of 200 to 250 cfm. Preferably, the air flow rate is approximately 214 cfm.  
         [0056]     The material  10  according to an embodiment of the invention, exhibits improved aging and wear resistance characteristics. The exemplary material has displayed better abrasion resistance than reticulated foam. For example, when subjected to abrasion cycle testing on a Wyzenbeek cycle tester, the exemplary material  10  completed a test cycle of about 30,000 cycles.  
         [0057]     According to another embodiment of the present invention, the material  10  may also have improved circular bend flex resistance or the resistance to compression and bending. A sample of a material  10  according to an embodiment of the present invention was subjected to a circular bend flex test. The test demonstrated that a force of 6.40 to 8.40 pounds was required to deform the material  10  and press the material  10  through a ring (the circular bend flex test). The circular bend flex test results are shown in Table 4.  
                                             TABLE 4                       Circular Bend Flex Test                                    Inventive   “LB”   “LB”   “LB”   “LB”   “LB”           Material   8.24   8.40   8.36   8.02   7.98           C-Peak   7.00   7.32   7.56   7.14   7.20           (60 psi)   6.60   6.86   7.36   6.96   6.80               6.70   6.98   6.86   6.80   6.40               6.44   6.70   6.74   6.64   6.50                      
 
         [0058]     In another embodiment, the fibers of the pile layer  24  can each have a tenacity in the range of 40 to 50 cN/tex. More specifically, the fibers of the pile layer  24  can have a tenacity of approximately 43 to 48 cN/tex. Preferably, the fibers of the pile layer  24  have a tenacity of approximately 46 cN/tex. In one embodiment, the fibers of the pile layer  24  can each have a diameter in the range of approximately 0.07 to 0.11 mm. More specifically, the fibers of the pile layer  24  can have a diameter in the range of approximately 0.08 to 0.10 mm. Preferably, the fibers of the pile layer  24  have a diameter of approximately 0.09 mm.  
         [0059]     In yet another embodiment, the material  10  can have a specific compactability in the range of 35 to 100 cm 3 . The specific compactability can be tested using the standard ASTM testing method designated D 6478-02. The ASTM International Designation D 6478-02 “Standard Test Method for Determining Specific Packability of Fabrics Used in Inflatable Restraints” is incorporated by reference herein. The ASTM testing method is modified so that a specimen of the material  10  is placed into the testing box in a single layer and is not folded. The compactability of a material  10  can be a factor in the design of products with spatial constraints. More specifically, the material  10  can have a specific compactability in the range of 40 to 90 cm 3 . Preferably, the specific compactability of the material  10  is in the range of 45 to 80 cm 3 .  
         [0060]     Given the disclosure of the present invention, one versed in the art would appreciate that there may be other embodiments and modifications within the scope and spirit of the invention. For example, the scope of the present invention includes a material  10  structure having multiple layers of porous material. For example, the material  10  may include one or more layers of reticulated foam in combination with one or more layers of spacer material. Other suitable combinations of porous material layers would also fall within the scope of the present invention. Furthermore, all modifications attainable by one versed in the art from the present disclosure within the scope and spirit of the present invention are to be included as further embodiments of the present invention. The scope of the present invention is to be defined as set forth in the following claims.