Abstract:
One exemplary aspect of the present disclosure relates to, among other things, a tunable cushion including a core made of a polymer material, and at least one topper layer adjacent the core, which is also made of a polymer material. Further, the core and the at least one topper layer provide a cushion assembly having a support factor of less than or equal to 4 with an Indentation Load Deflection (ILD) determined using a 4 inch batt sample of the cushion assembly.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 61/856,381, filed Jul. 19, 2013, the entirety of which is herein incorporated by reference 
     
    
     BACKGROUND 
       [0002]    A typical cushion assembly used in seating applications includes an aesthetic cover surrounding a soft and resilient filler material such as polyurethane foam, springs and the like. Most cushions are constructed with material which provides a desired support and comfort to the user. Polyester fiber toppers are sometimes used on top and side of the cushion assembly on which a user may sit to provide a better “hand,” which is a desired feel. An additional wrap is occasionally used to provide a desired function such as to provide improved resistance against flammability. The wrapped and/or padded core structure, usually made up of polyurethane foam is inserted into an aesthetic cover. The foam core is generally the same dimensions as the cover or very slightly larger than the cover. 
         [0003]    The feel of foam cushions is very customizable. This is done by changing the foam chemistry for a given density. One measurement of “feel” for a cushion is the Indentation Load Deflection, ILD, which is determined using industry guidelines. The ILD is the amount of pounds (measured as resistant force) required to compress a 4 inch thick, 15 inch×15 inch sample to 3 inches (or 25% of original height). For example, a typical 4 inch tall polyurethane foam cushion having a density (in pounds per cubic foot, or “pcf”) of 1.0 pcf has an ILD of 30. 
         [0004]    In addition due to processing and chemistry changes this is tunable within a range of 10-40 ILD; a density of 1.2 pcf is tunable to 20-50 ILD; and so on. 
         [0005]    A given foam cushion must also exhibit an acceptable comfort or “support factor,” typically in the range of 1.7-4.0. The support factor calculated by dividing the force required to compress a 4″ thick sample to 65% of its height by the force required to compress to 25% of its height; i.e. comfort factor=(ILD @65%)/(ILD @25%). In addition to comfort, a standard foam cushion must survive industry durability tests over several thousand cycles during which the foam cushion must substantially maintain its height and shape while maintaining the support factor. Polyurethane foam cushions are highly tunable in that a foam material can be easily selected to provide a desired density, ILD and support factor, which in turn provides the durability for a given application. For polyester fiber cushions, the ILD is very closely tied to the density and such fiber cushions are not easily tuned to provide both comfort and durability. To provide better durability fiber cushions must be made very dense but that is generally not acceptable as comfortable for the end user. It should be understood that while ILD is mentioned relative to foam, that ILD tests apply outside the world of foam, and can be applied to batts made of any type of material (including polymer batts). 
         [0006]    Foam is generally very resilient and tunable but the chemistry is such that in its native state it is very highly flammable, further the process of making foam is considered harmful to the environment. Several attempts to replace foam with polyester fiber have resulted in different formed, thermo-bonded or loose fiber constructions, but none have been able to achieve desired comfort and performance sufficient for broad commercial viability due to the difficulty in tuning. Loose fibers or thermo-bonded fibers are sometimes used in outdoor cushion applications to provide improved long-term resiliency over foam. The fibers are loosely arranged relative to one another in an unconnected fashion, permitting the fibers to shift uninhibited within the cover. Such outdoor cushions are not very durable and as such not suitable for conventional seating and bedding applications. 
         [0007]    Tufting has been used to secure multiple layers to one another or provide an aesthetically pleasing exterior cover. Often, the tufts are visible through the cover. For example, tufting is used in futons to secure the multiple layers to one another and the exterior cover. The exterior cover is arranged rather loosely about the layers. 
       SUMMARY 
       [0008]    One exemplary aspect of the present disclosure relates to, among other things, a tunable cushion including a core made of a polymer material, and at least one topper layer adjacent the core, which is also made of a polymer material. Further, the core and the at least one topper layer provide a cushion assembly having a support factor of less than or equal to 4 with an Indentation Load Deflection (ILD) determined using a 4 inch batt sample of the cushion assembly. 
         [0009]    These and other features of the disclosure can be best understood from the following specification and drawings, the following of which is a brief description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a perspective view of an example cushion assembly. 
           [0011]      FIG. 2  is a cross-sectional view of a prior art foam cushion at a manufactured height. 
           [0012]      FIG. 3A  is a side elevational view of a randomly oriented fiber cushion having a manufactured height for the same cushion application as the foam cushion illustrated in  FIG. 2 . 
           [0013]      FIG. 3B  is a schematic view of the randomly oriented fibers interlinked to one another with binder material. 
           [0014]      FIG. 4  is a cross-sectional view of the fiber cushion illustrated in  FIG. 3A  that has been tufted. 
           [0015]      FIG. 5  is a cross-sectional view of a cushion having topper layers. 
           [0016]      FIG. 6  is a side elevational view of an example tuft. 
           [0017]      FIG. 7  is a cross-sectional view of the cushion illustrated in  FIG. 5  with a wrap and inserted into a cover. 
           [0018]      FIG. 8  is a side elevational view of a cushion assembly according to the disclosure compared to a cushion assembly using the foam illustrated in  FIG. 2  for the same cushion application. 
           [0019]      FIG. 9  is a cross-sectional view a cushion having three-dimensional netted topper layers. 
           [0020]      FIG. 10A  is a view of a batt of material used to provide the topper layers of  FIG. 9 . 
           [0021]      FIG. 10B  is a close-up view illustrating the detail of the resin filaments in  FIG. 10A . 
       
    
    
     DETAILED DESCRIPTION 
       [0022]    A cushion assembly  10  is schematically illustrated in  FIG. 1 . Initially, while the term “cushion” is used herein, this term is not meant to be limited to any particular type of cushion assembly. In particular, the term “cushion” as used herein includes both seating and sleeping pads, such as mattresses. The cushion assembly  10  includes a cover  11  having a perimeter panel  12  joined to opposing cover panels  14  at edge  20 . Typically, the perimeter and cover panels  12 ,  14  are sewed to one another at the adjoining edges  20  using a welting. A closure  18 , such as a zipper, edge tape or hook-and-loop fastener, is provided at a seam  16  to permit insertion of a cushion into a cavity provided within the cover  11 . 
         [0023]      FIG. 2  schematically illustrates a typical foam cushion  22  having a width  30  and a design height  24 . The design height  24  generally corresponds to the height of the perimeter panel  12  for the cover into which the foam cushion  22  will be inserted. The foam cushion  22  is generally the same dimensions as the cover into which it is inserted or very slightly larger than the cover. For example, a 4 inch, 1.4 pcf density foam cushion may be manufactured for a 4 inch finished cushion assembly height. As a result, the finished cushion assembly is virtually the identical shape and size, and perhaps slightly larger, as the manufactured dimensions of the foam cushion  22 . 
         [0024]    A manufactured fiber cushion  26  is illustrated in  FIG. 3A . The manufactured fiber cushion  26  is constructed from a single layer of randomly oriented polyester staple fibers interlinked to one another using a binder material, which is elastomeric in one example. In one example, the staple fiber and binder material are the same, and are both polymer materials. The manufactured fiber cushion  26  includes a manufactured height  28  that is greater than a desired design finished height of the cushion  24 . For example, if a finished height of 4 inches is desired, the manufactured fiber cushion  26  may be manufactured with 1.0 pcf of polyester fibers at a 5.6 inch height. The binder material is heated to a melting temperature to secure the staple fibers to one another once the melted binder material has solidified and produce a non-layered core batt. The core is compressed during its manufacture to provide a desired density, which is also affected by the staple and binder materials selected. The interlinked randomly oriented staple fibers  58  are shown schematically in more detail in  FIG. 3B . 
         [0025]    The staple fibers  52  include a fiber length  56  that is distributed in all three dimensions (x, y, z). In one example, the average fiber length  56  is approximately 2.5 inches. The manufactured height  28  is greater than the fiber length  56 , which enables the fibers to be randomly distributed to the full extent of their fiber length in all three directions. This is contrasted with typical randomly oriented fiber manufacturing processes, such as cross lapping or air-laying, that orient the fibers in only two directions to form a relatively thin layer substantially less than the length of its staple fibers. Numerous cross lapped or air-layed layers are bonded in some fashion to one another to form a multi-layered fiber batt consisting of very thin layers. Fiber batts produced using an air-lay process do not make suitable cushions because they lose height over time to an unacceptable degree. The fiber batt formed according to this disclosure is typically an inch or greater in height, as opposed to the thin layers produced in air-lay processes, which are only fractions of an inch thick. 
         [0026]    Referring to  FIG. 4 , the manufactured fiber cushion  26  is reduced from the manufactured height  28  to a tufted height  31  using one or more tufts  33 , which may be rubber-like, for example. The tufts  33  include a body  37  extending between opposing heads  35 , as illustrated in  FIG. 6 . The tuft  33  extends through the tufted cushion  36  to opposing surfaces  32 . The width  30  of the tufted cushion  36  is generally the same as the width of the manufactured fiber cushion  26 . Other tufting configurations can be used. For example, a lace and felt arrangement can be used, or a button and lace arrangement can be employed. Various tufting configurations can be used separately or in combination with one another for a given cushion assembly. The tuft  33  is not visible through the cover  11  with the cushion assembly  10  exposed and not otherwise in use. Thus, the presence of the tuft  33  is not apparent to an observer, which provides an aesthetically pleasing appearance. 
         [0027]    The manufactured fiber cushion  26  includes a first density that is considerably less than the desired finished density of the cushion once placed within the cover. The cushion height is reduced from the manufactured height  28  to the tufted height  31 , at least 5%, and in one example at least 10%, which increases the density from the manufactured fiber cushion  26  to the tufted cushion  36  at least 10%. In one example, if the desired finished height of the cushion within the cover is approximately 4 inches, the manufactured height  28  may be 5.6 inches, which when tufted and stuffed into a 4 inch high cover assembly  10  provides the comfort and resiliency of 1.4 pcf cushion that could not otherwise be provided by a 1.4 pcf cushion manufactured at a 4 inch height. Thus, the cushion will be reduced in height approximately 28%. In one example, the density is increased 40%. The example density of the manufactured fiber cushion  26  is 1.0 pcf for the 5.6 inch manufactured height. 
         [0028]    An example tufted cushion  136  is illustrated in  FIG. 5 . The tufted cushion  136  includes a core  38  and topper layers  40  arranged on either side of the core  38  that are tufted together as an assembly. In one example, both the core  38  and the topper layers  40  are manufactured of three dimensionally randomly oriented polyester fiber interlinked with one another as described above. In other examples, as will be explained below, the core  38  and topper layers  40  may be provided by a material other than randomly oriented polyester fibers. The tufts extend through the core  38  and the topper layers  40 . Other methods of attaching the core  38  and topper layers  40  can be used such as adhesive. The topper layers  40  may be constructed separately from the core  38 , for example. Each topper layer is compressed during its manufacture to provide a desired density, which is also affected by the staple and binder materials selected. The topper layers  40  are of a lower density and different fiber blend than the core  38  to provide a desired hand and performance. 
         [0029]    Referring to  FIG. 7 , the tufted cushion assembly  136  can be enclosed in a wrap  50 , which provides functions like desired flammability properties and/or hand, for example. The wrap  50  is arranged around the exterior surfaces of the tufted cushion  36 , including the tufts  33  and provides an actual height  48  of the tufted cushion assembly  136 . A perimeter height  42  is defined by the height of the perimeter panel  12 . The perimeter height  42  is approximately 90-98% of the actual or desired design height  24 . The cover panels  14  provide a desired design height  44  (which should be very close to  24  and is determined by the cushion designer) and includes a crown or apex  46 . The cover gradually increases to a location central to the cover  11  to provide the apex. The desired design height  44  is greater than the perimeter height  42 , and in one example at least approximately 120% of the perimeter height  42  at the apex  46 . The cushion assembly  10  has a crowned surface or apex  46 , whereas a cushion assembly using a foam cushion has a generally flat or a nominal crown surface  60 , illustrated in  FIG. 8 . 
         [0030]    The disclosed cushion assembly and batt having randomly oriented staple fibers interlinked to one another using a binder material is constructed with the following specifications: 
         [0031]    CORE: 
         [0032]    density at manufactured height: 0.8-5.0 pcf, in one example approximately 2.8 pcf 
         [0033]    manufactured thickness of 1.0-6.0 inch 
         [0034]    20-90 ILD 
         [0035]    TOPPER: 
         [0036]    density at manufactured height: 0.6-2.0 pcf 
         [0037]    manufactured thickness of 0.5-4.0 inch 
         [0038]    10-55 ILD 
         [0039]    CUSHION ASSEMBLY (core and at least one topper layer): 
         [0040]    density at desired design height, tufted: 1.0-3.0 pcf, in one example, approximately 1.4 pcf 
         [0041]    support factor: ≦4, with the ILD determined using a 4 inch thick sample at installed height, tufted 
         [0042]    The performance of the batt can be increased by using more binder and a higher denier fiber. Decreasing the amount of binder and using lower denier fiber decreases performance and cost. The binder and staple fibers for each layer are selected to obtain the desired ILD for each layer in order to “tune” the overall cushion assembly. In one example, a tunable fiber cushion includes a batt of randomly oriented first polyester fibers interlinked with a first binder material. The batt has a non-layered core with a first manufactured height defined by opposing surfaces and that includes a first density. The first density is 0.8-5.0 pcf. At least one topper layer of randomly oriented second polyester fibers is interlinked with a second binder material. A topper layer includes a second manufactured height of a second density. The topper layer is arranged on a side adjacent to one opposing surface. The second density is 0.6-1.4 pcf. A tuft extends through the batt and the topper layer to provide a tufted cushion assembly having a tufted height and a third density at the tufted height that is greater than the first density or the second density. The third density is 1.0-3.0 pcf. The tufted cushion assembly at the tufted height provides a support factor of less than or equal to 4 with an ILD and is determined using a 4 inch batt sample of the batt at the tufted height. 
         [0043]    In a further embodiment of this disclosure, a cushion  136   a  includes a netted topper layer  40   a  provided by a three-dimensional netted material, as illustrated in  FIG. 9 , in place of the randomly oriented polyester topper layer  40  illustrated of  FIGS. 5 and 7 . As illustrated in  FIG. 10B , the netted layer  40   a  is made of a plurality of helically arranged thermoplastic resin filaments  62  partially thermally bonded to at least one of the other thermoplastic resin filaments, such as at points  64 . In this way, the thermoplastic resin filaments  62  are randomly entangled with one another, and provide a layer, such as the netted layer  40   a  of  FIG. 10A . The random entangling of the resin filaments  62  provides substantial spacing, or gaps, between the filaments, which in turn provides the netted layer  40   a  with increased breathability without compromising qualities such as resiliency, fire-resistance, and the overall performance of the cushion. 
         [0044]    An example of the netted layer  40   a  is disclosed in U.S. Pat. Nos. 7,625,629 and 7,993,734 to Takaoka, the entirety of which are herein incorporated by reference. The Takaoka patents describe example methods for making the netted material, as well as describe various embodiments of the netted material. As mentioned, the netted material made from the methods disclosed in the Takaoka patents are relatively lightweight and breathable, but still provide a high level of support. The method for making the netted material can be modified to provide a batt of a desired density. Modifying the density of the netted layer  40   a  allows one to “tune” the overall cushion assembly. 
         [0045]    In the cushion  136   a  shown in  FIG. 9 , the netted layers  40   a  are provided on opposing sides of the batt  38 , and the overall assembly provides a support factor of less than or equal to 4 with an ILD determined using a 4 inch thick sample. While two netted layers  40   a  are illustrated in  FIG. 9 , another example of the cushion  136   a  includes only one layer of netted layer  40   a  (e.g., only a top layer), and the thickness of that single netted layer  40   a  is also provided such that the assembly exhibits a support factor of less than or equal to 4 with the ILD determined using a 4 inch thick sample. 
         [0046]    In yet another example, the cushion  136   a  may include a batt  38   a  provided by a layer of three-dimensional netted material, and topper layers  40   a  provided by randomly oriented polyester fibers. In still another example, the cushion  136   a  may include a batt  38   a  and one or more topper layers  40   a  provided by separate layers of three-dimensional netted material. In this case, the density of the three-dimensional netted material providing the batt  38   a  would be higher than the density of the three-dimensional netted material providing the topper layers  40   a . In any of these arrangements, the cushion  136   a  exhibits a support factor of less than or equal to 4 with the ILD determined using a 4 inch thick sample. While a tufted assembly is illustrated in  FIG. 9  (e.g., see tufts  33   a ), it should be understood that the layers may be joined together in other ways, such as by using an adhesive. 
         [0047]    The cushion  136   a  is thus tunable and provides an acceptable “feel” to a user, just as the cushion of  FIGS. 3A-8  does. The cushion  136   a  further maintains its shape and elasticity over time by minimizing the exposure of the batt (or core)  38   a  to the body heat of a user, for example. 
         [0048]    Although example embodiments have been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of the claims. For that reason, the following claims should be studied to determine their true scope and content.