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.
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.
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.
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).
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.
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.
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.
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.
A cushion assembly 10 is schematically illustrated in
A manufactured fiber cushion 26 is illustrated in
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.
Referring to
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.
An example tufted cushion 136 is illustrated in
Referring to
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:
CORE:
density at manufactured height: 0.8-5.0 pcf, in one example approximately 2.8 pcf
manufactured thickness of 1.0-6.0 inch
20-90 ILD
TOPPER:
density at manufactured height: 0.6-2.0 pcf
manufactured thickness of 0.5-4.0 inch
10-55 ILD
CUSHION ASSEMBLY (core and at least one topper layer):
density at desired design height, tufted: 1.0-3.0 pcf, in one example, approximately 1.4 pcf
support factor: ≦4, with the ILD determined using a 4 inch thick sample at installed height, tufted
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.
In a further embodiment of this disclosure, a cushion 136a includes a netted topper layer 40a provided by a three-dimensional netted material, as illustrated in
An example of the netted layer 40a 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 40a allows one to “tune” the overall cushion assembly.
In the cushion 136a shown in
In yet another example, the cushion 136a may include a batt 38a provided by a layer of three-dimensional netted material, and topper layers 40a provided by randomly oriented polyester fibers. In still another example, the cushion 136a may include a batt 38a and one or more topper layers 40a provided by separate layers of three-dimensional netted material. In this case, the density of the three-dimensional netted material providing the batt 38a would be higher than the density of the three-dimensional netted material providing the topper layers 40a. In any of these arrangements, the cushion 136a 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
The cushion 136a is thus tunable and provides an acceptable “feel” to a user, just as the cushion of
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.
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
Number | Date | Country | |
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61856381 | Jul 2013 | US |