WO2015152896A1

WO2015152896A1 - Assembly and method for removing liquid byproducts from foam

Info

Publication number: WO2015152896A1
Application number: PCT/US2014/032487
Authority: WO
Inventors: Carlotta M. PAULSEN; Raymond E. COURNEY
Original assignee: Tempur-Pedic Management, Llc
Priority date: 2014-04-01
Filing date: 2014-04-01
Publication date: 2015-10-08

Abstract

An assembly for removing liquid byproducts from a piece of foam includes a body engageable with the foam for applying a compressive force to the foam, thereby causing liquid byproducts in the foam to migrate toward a surface of the foam, a vaporization device to facilitate evaporation of the liquid byproducts from the surface of the foam, and a filter for capturing the evaporated byproducts.

Description

ASSEMBLY AND METHOD FOR REMOVING

LIQUID BYPRODUCTS FROM FOAM

FIELD OF THE INVENTION

|00 1 ] The present Invention relates to loam, and more particularly to an assembly and method for removing liquid byproducts from foam.

BACKGROUND OF THE INVENTION

10002] Byproducts are often produced during the manufacture of foam. Such byproducts are typical iy in liquid form, slowly migrate to the exterior of the foam over time, and evaporate in response to natural convection currents flowing around the foam. In some closed-cell foams (e.g., viscoelastlc foam), such byproducts may not. be entirely removed from the foam by such an evaporation process before packaging of the product incorporating the foam, thereby trapping the byproducts within the product packaging.

SUMMARY OF THE IN VENTION

[ O03J The invention provides. In one aspect, an assembly for removing liquid byproducts from a piece of foam. The assembly includes a body engageable with the foam for applying a compressive force to the foam, thereby causing liquid byproducts in the foam to migrate toward an exterior surface of the foam, a vaporization device to facilitate evaporation of the liquid byproducts from the surface of the foam, and a filter for capturing the evaporated byproducts,

[00 1 The invention, provides, in another aspect, a method for removing liquid byproducts from a piece of foam. The method includes applying a compressive force to the foam, thereby causing liquid byproducts in the foam to migrate toward an exterior surface of the foam, vaporizing the liquid byproducts from the surface of the foam, and capturing the evaporated byproducts.

[0005] Other features and aspects of the invention will become apparent by consideration of the following detailed description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Fl^'Ci 1 is a schematic of an assembly for removing liquid byproducts from foam, in accordance with an embodiment of the invention,

{0007] Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not. limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the accompanying drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of descriptio and should not be regarded as limiting.

DETAILED DESCRIPTION

{0908 j FIG. 1 illustrates an assembly 10 for removing liquid byproducts from a piece of foam 14, Such foam 14 may include either an open-cell foam or a closed-cell foam, an example of which is viscoelastic foam. Viscoelastic foam is sometimes referred to as "memory fo m^" or "low resilience foam," and is oftentimes used in mattresses. Coupled with the slow recovery characteristic of viscoelastic foam, viscoelastic foam can at least partially conform to a user^'s body or body portion (hereinafter referred to as "body-'), thereby distributing the force applied by the user's body upon the viscoelastic foam. As such, viscoelastic foam can provide a relatively soft and comfortable surface for the user^'s body.

[0009] Viscoelastic foam, when used in a mattress application, can. include a hardness of at least about 20 N and no greater than about 80 N for desirable softness and body-conforming qualities. Alternatively, the viscoelastic foam may have a hardness of at least about 30 N and no greater than about 70 N. In still other alternative embodiments, the viscoelastic foam may have a hardness of at least about 40 N and no greater than about 60 N. Unless otherwise specified, the hardness of a material referred to herein is measured by exerting pressure from a plate against a sample of the .material to a compression of 40 percent, of an original thickness of the material at appro imatel room temperature (e.g., 21 to 23 degrees Celsius). The 40 percent compression is held for a set period of time, following the International Organization of Standardization (ISO) 2439 hardness measuring standard. [001 j Viscoelastie foam, when used in. a mattress application, can also have a density providing a relatively high degree of material durability. The density of the viscoelasiic foam can impact other characteristics of the foam, such as the tnanner in which the viscoelasiic foam responds to pressure, and the feel of the viscoelasiic foam, in the illustrated embodiment, the viscoelasiic foam has a density of no less than about 30 kg/n and no greater than about 150 kg/nr . Alternatively, the vtscoelastic foam may have a density of at least about 40 kg/nr' and no greater than about 135 kg/^ητ*. In still other alternative embodiments, the vtscoelastic foam may have a density of at least about 50 lcg nv' and no greater than about 120 kg r.

[00111 The viscoelasiic foam 14 of FIG. i can be non-reticulated or reticulated.

Reticulated viscoelasiic foam has characteristics that are well suited for use in a mattress, including the enhanced ability to permit fluid movement through the reticulated viseoelastic foam, thereby providing enhanced air and/or heat movement within, though, and away from the vtscoelastic foam when used in a mattress application. Reticulated foam is a. cellular foam structure in which the cells of the foam are essentially skeletal. In other words, the cells of the reticulated foam are each defined by multiple apertured windows surrounded by struts. The eel! windows of the reticulated foam can be entirely gone (leaving only the cell struts) or substantially gone. For example, the foam may be considered "reticulated" if at least 50 percent of^" the windows of the cells are missing (i.e.. windows having apertures therethrough, or windows that are completely missing and therefore leaving only the cell struts). Such structures can. be created by destruction or other removal of cell, window material, or preventing the complete formation of cell windo ws during the manufacturing process..

[0012 J Although the assembly shown in F1.G. 1 can be used for removing foam manufacturing byproducts from any foam, the assembly is particularly suited for use with non- reticulated, non-molded viseoelastic foam 14. Vtscoelastic foam 14 includes closed cells between which byproducts in liquid form ma become trapped following the manufacture of the viseoelastic foam 14. Such liquid byproducts can be undesirable in some applications and end products. To expedite removal of the liquid byproducts, the foam 14 may be directed through the assembly 10 shown in FIG. 1. It should be understood that the assembly 10 can be used in conjunction with a post-processing manufacturing operation, or inline with the manufacture of the foara 1.4. For example, when used in a post-processing manufacturing operation, the assembly 10 ma be remotely located from the remainder of the manufacturing line, and pre-cut slabs of foam 14 may be directed through the assembly 10 to expedite removal of the liquid byproducts from the foam 14. Alternatively, when used inline with the manufacturing line, a continuous slab of cured foam 14 may be directed through the assembly 10 to expedite removal of the liquid byproducts from the foam 14. The processed continuous foam slab may then be cut into individual slabs having discrete lengths,

[0 131 With continued reference to FIG. 1 , the assembly 10 includes opposed cylindrical rollers 18 engageabie with the foam 14 for applying a compressive force to the foam 14, thereby causing the liquid byproducts in the foam 14 to migrate toward an exterior surface 22. of the foam 14. Discrete amounts of liquid byproducts are shown in FIG. 1 as individual dots or specks within the interior of the foam 14. In the illustrated embodiment of the assembly 10, the rollers 18 are spaced apart from each other to define a nip 26 having a height H of about 50% of a thickness T of the foam 14. Alternatively, the rollers 18 may be spaced apart from each other to define a nip height H between about 20% and about 80% of the thickness T of the foam 14. Consequently, as the foam 14 is compressed between the rollers 18, the thickness T of the ibam 14 is reduced by at least about 80% and about 20%. In the illustrated embodiment of the assembly 10, the rollers 18 each include a diameter D that correlates with a nip length L (i.e., a linear dimension along which the foam 14 is in contact with the rollers 18} of about 100% of the thickness T of the foam .14. Alternatively, the diameter D of the rollers 18 may be sized to provide a nip length L between about 50% and about 150% of the thickness T of the foam 14.

{0014] Although not shown in FIG, 1, the assembly 10 may also include a synchronous drive assembly for imparting rotation to both of the rollers 18, thereby also pulling the foam 14 through the nip 26 defined between the rollers 18. Alternatively, the rollers 18 may be non- driven, and the foam 14 may be moved through the nip 26 by another component of the assembly 10 (e.g., if used in a post-processing operation) or the manufacturing line (e.g., if the assembl is used inline with the manufacturing line). As yet another alternative, the rollers 1 may be translatable (in addition to being rotatable) along the length of the foam 14 for compressing the foam 1 in a rolling manner. With this alternative, the foam 14 may also be translatable with the rollers 18 (albeit at a different rate), or the foam 14 may be stationary while the rollers 18 move. As a further alternative, the assembly 10 may include only a single roller 18 in facing relationship with a fixed surface (not shown) over which the foam 14 slides. In such an arrangement, She nip would be defined between the single roller 1 8 and the fixed surface. Also, in some embodiments either or both rollers 18 are adjustable to different positions with respect to one another in order to change the size of the nip 26. In this manner, the ni 26 can be changed to accommodate foam of different thicknesses, and can also be changed to exert greater or less pressure upon foam passing therethrough for different desired byproduct extraction amounts and rates.

(00151 With continued reference to FIG. 1 , the assembly 10 also includes a vaporization device 30 to facilitate evaporation of the liquid byproducts from the exterior surfaces 22 of the foam 1 . In the illustrated embodiment of the assembly 10, the vaporization device 30 includes nozzles 34 positioned adjacent each of two opposite exterior surfaces 22 of the foam 14 for directing a flow of gas across both exterior surfaces 22 of the foam 14. The nozzles 34 are positioned in relatively close proximity to the exterior surfaces 22 of the foam 14, and the outlet, of each of the nozzles 34 may be shaped, to discharge the flow of gas at a wide angle (e.g., a 30 or 40 degree fan angle) oriented along the width of the foam 14 (i.e., into and out of the page of FIG. 1 ). Therefore, the width of the foam 14 and the proximity of the nozzles 34 to the foam 14 will at least partially determine the quantity of nozzles 34 used on each side of the foam 14. Also, in the illustrated embodiment of the assembl 10, the nozzles 34 are oriented substantially transverse to the foam 14. In other embodiments, at least some of the nozzles 34 may be oriented at an oblique angle relative to the foam 34. The flow of gas discharged from the nozzles 34 may include at least one of nitrogen, carbon dioxide, and air. Alternatively, other gases and/or gas mixtures may be utilized. Furthermore, the flow of gas is discharged at a rate of at least about 25 meters/sec to create forced convention currents over the exterior surfaces 22 of the foam 14 and to facilitate rapid evaporation, of the liquid byproducts at or near the exterior surfaces 22 of the foam 14. It is contemplated thai greater fan speeds are possible, such as up to 180 meters/sec. It is expected, however, that the rate of gas flow from the nozzles 34 should be maintained below a value which could be determined empirically through testing and. which might otherwise cause damage to the foam 14. It Is also expected that the temperature and/or humidity of the gas flow from the nozzles 34 has an effect on the rate at which the liquid byproducts at or near the exterior surfaces 22 are evaporated from the foam 14. For example, the gas flow may have a temperature of at least about 30 degrees Celsius, but no greater than about 150 degrees Celsius (which might otherwise damage the foam 14). Likewise, the gas flow may have a relative humidity of at least about 30%, but no greater than about 80%. Accordingly, gas supplied to any number of the nozzles 34 can be heated or cooled as desired prior to reaching the nozzles 34 and/or upon discharge from the nozzles 34.

[001 ] With continued reference to FIG. 1 , the assembly ] 0 further includes a filter 38 on each side of the foam 14 for capturing the evaporated byproducts, in the illustrated embodiment of the assembly 10, the filters 38 are incorporated in respective vacuum assemblies 42 which, like the nozzles 34, are positioned in relatively close proximity to the foam 1.4. The vacuum assemblies 42 are also positioned in relatively close proximity to the nozzles 34 to ensure that substantially all of the evaporated byproducts are collected by the vacuum assemblies 42 rather than being released to the atmosphere. Each of the illustrated vacuum assemblies 42 includes a hood 46 (in which the filter 38 is located) and a vacuum device 50 positioned downstream of the hood 46 for creating a vacuum airflow through, the hood 46 and filter 38. The filters 38 can include carbon material for adsorbing the evaporated byproducts. The filters 38 may also be removed and replaced when necessary upon saturation, with evaporated byproducts. In other embodiments, the vacuum assemblies 42 are not provided with filters 38. in which cases the byproducts can instead be removed and/or processed at. another location (e.g., at one or more locations downstream from the vacuum devices 50 where byproducts drawn up irom the foam are transported). j00l7J hi operation of the assembly 10 illustrated in FIG. 1 , a continuous slab of foam 14

(or, alternatively multiple slabs of foam 14 having discrete lengths) is/are fed between the rollers 18. As the foam 14 is moved through the nip 26. the foam. 14 is compressed, thereby causing liquid byproducts in the foam 14 to migrate toward the exterior surfaces 22 of the foam 14. The liquid byproducts are then vaporized by the gas flow from the nozzles 34, and the evaporated byproducts are captured withi the carbon-conlai ning filters 38 of the respective vacuum assemblies 42. The steps of compressing the foam 14, vaporizing the liquid byproducts at or near the exterior surfaces 22 of the foam 14, and capturing the evaporated byproducts can be done in a consecutive manner at a high rate of speed (for example, up to about. 100 feet per minute). As a result, this process can remove a substantial amount of liquid byproducts from the foam 14 prior to incorporating the foam 14 into a product and packaging the foam 14 and/or product for subsequent sale.

[0Q18J Although the embodiments of the present invention described and illustrated herein utilize nozzles 34. filters 38. and vacuum devices 50 on both sides of foam passin through the nip 26, it will be appreciated that any or all of these devices can be located on a single side of the passing foam. Such alternative arrangements of devices as described herein may not have the capacity for gas discharge, byproduct evaporation, and/or byproduct removal as systems such as that illustrated in FIG. L but .may still provide the full capacity needed in many applications.

|00J | in some embodiments, at least some of the nozzles 34 and/or vacuum devices 50

(with or without filters 38) ca be incorporated into the roller 18, such as by providing either or both rollers with nozzles 34 on exterior surfaces above (e.g., embedded or recessed nozzles located along any desired length of the rollers 18). or by exerting a vacuum through either or both ends of either or both rollers 1 8 and through apert ured portions of the roller^'s) 18. Any of a number of vacuum roll designs and/or web manipulatio rolls can be used for this purpose, whether in conjunction with nozzles 34 and/or vacuum devices 50 positioned as described herein or otherwise.

10020] ^'Various features of the invention are set forth in the follo wing claims.

Claims

CLAIMS What is claimed is:

1 . An assembly for removing liquid byproducts from a piece of foam, the assembly corn pris ng:

a body engageable with the foam for applying a compressive force to the foam, thereby causing liquid byproducts in the foam to migrate toward an exterior surface of the foam;

a vaporization device to facilitate evaporation of the liquid byproducts from the exterior surface ofthe foam; and

a filter for capturing the evaporated byproducts.

2. The assembly of claim 1. wherein the body has circular cross-sectional shape.

3. The assembly of claim 2. wherein the body is a cylindrical roller.

4. The assembly of claim 1 , wherein the vaporization device includes one or more nozzles for directing a flow of gas across the exterior surface of the foam.

5. The assembly of claim L wherein the vaporization device provides a flow of a gas across the exterior surface ofthe foam.

6. The assembly of claim 5, wherein the gas includes at least one of nitrogen, carbon dioxide, and air.

7. The assembly of claim I , wherein the body is a first body, and wherein the assembly further includes a second body positioned opposite the first body.

8. Hie assembly of claim 7, wherein the foam is positioned between the first and second bodies, and wherein the second bod is engageable with the foam to apply a compressive force to the foam, in an opposite direction as the compressive force applied by the first body.

9. The assembly of claim 1 . wherein the foam includes at least one of viscoeiastic foam and non-molded foam.

10. The assembly of claim 1 , wherein the filter includes carbon material for adsorbing the evaporated byproducts.

1 1 . The assembly of claim I, further comprising a vacuum device for creating a vacuum airflow and drawing the evaporated byproducts toward the filter.

12. A method for removing liquid byproducts from a piece of foam, the method comprising:

applying a compressive force to the foam, thereby causing liquid byproducts in the foam to migrate toward an exterior surface of the foam;

vaporizing the liquid byproducts from the exterior surface of the foam; and capturing the evaporated byproducts.

13. The method of claim 12, wherein applying the compressive force to the foam includes reducing a thickness of the foam by at least about.20% and no greater than about 80%.

14. The method of claim 12. wherein the compressive force is at least about 40N.

15. The method of claim 12, wherein vaporizing the liquid byproducts includes flowing a gas across the exterior surface of the foam.

16. The method of claim 1 5. wherein flowing the gas occurs at a rate of at least about 60 raph 25 meters/sec.

17. The method of claim 15, wherein the gas flow has a temperature of at least about 30 degrees Celsius and no greater than about. 1.50 degrees Celsius.

18. The method of claim 15. wherein the gas ^"flow has a relative humidity of at least about 30% and no greater than about 80%.

19. The method of claim 15, wherein the gas includes at least one of nitrogen, carbon dioxide, and air.

20. The method of claim 12, wherein capturing the evaporated byproducts includes adsorbing the evaporated byproducts with a carbon filter.

21. The method of claim 12, wherein the foam includes at least one of viscoelastic foam and non-molded foam.

The .method of claim 12, wherein applying the compressive force to the foam includes

compressing the foam with a body, and

moving the foam and the body relative to each other.

23. The method of claim 22, wherein the body is a first body, and wherein compressing the foam includes compressin the foam between the first body and a second body.

24. The method of claim 22, wherein moving the foam includes moving the foam relative to the body.

25. The method of claim 12, wherein capturing the evaporated byproducts includes creating a vacuum airflow, and

drawing the evaporated byproducts into a carbon filter with the vacuum airflow.