US20250089904A1

US20250089904A1 - Mattress assemblies including macroencapsulated phase change material

Info

Publication number: US20250089904A1
Application number: US18/814,732
Authority: US
Inventors: Lakshya Deka
Original assignee: Serta Simmons Bedding LLC
Current assignee: Serta Simmons Bedding LLC
Priority date: 2023-08-28
Filing date: 2024-08-26
Publication date: 2025-03-20

Abstract

Mattress assemblies include an upholstery foam layer including one or more channels, wherein at least a portion of the channels include a macroencapsulated phase change material at least partially filling the channel; and a pump including a conduit configured to exhaust air from the upholstery layer. The mattress assemblies can include an underlying layer including air bladders or cylindrical foam springs for adjusting firmness of the mattress assemblies

Description

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of U.S. Provisional Application No. 63/579,123, filed on Aug. 28, 2023, incorporated herein by reference in its entirety.

BACKGROUND

The present disclosure generally relates to mattress assemblies including microencapsulated phase change materials.
Phase change is a term used to describe a reversible process in which a solid turns into a liquid or a gas. The process of phase change from a solid to a liquid requires energy to be absorbed by the solid. When a phase change material (“PCM”) liquefies, energy is absorbed from the immediate environment as it changes from the solid to the liquid. In contrast to a sensible heat storage material, which absorbs and releases energy essentially uniformly over a broad temperature range, a phase change material absorbs and releases a large quantity of energy in the vicinity of its melting/freezing point. Therefore, a PCM that melts below body temperature would feel cool as it absorbs heat, for example, from a body prone on a mattress including the same. Phase change materials, therefore, include materials that liquefy (melt) to absorb heat and solidify (freeze) to release heat. The melting and freezing of the material typically take place over a narrow temperature range.
Microencapsulated PCMs have been used in various applications ranging from household insulation to clothing. Dispersal in pre-formed foams is expensive, involves an additional step after formation of the foam, and typically does not uniformly distribute the PCMs throughout foams greater than one inch in thickness. In these types of applications, the PCM material itself is a relatively inexpensive long chain hydrocarbon that is subsequently microencapsulated. Exemplary long chain hydrocarbons include octadecane, nonadecane, icosane, heptadecane, and the like. These materials have relatively low melting point temperatures. However, the microencapsulation process dramatically increases the price of the PCM. As one decreases the overall size of the microencapsulate, the net volume of PCM within the microencapsulated PCM significantly decreases whereas the volume taken up by the microencapsulate increases.

BRIEF SUMMARY

Disclosed herein are mattress assemblies including an upholstery foam layer proximate to a sleeping surface of the mattress assembly comprising a plurality of channels and a macroencapsulated phase change material provided within at least one or more of the channels; and an underlying layer including a pump and a plurality of conduits configured to exhaust air from the upholstery layer.
The disclosure may be understood more readily by reference to the following detailed description of the various features of the disclosure and the examples included therein.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the figures wherein the like elements are numbered alike:

FIG. 1 illustrates a cross-sectional view of a mattress assembly including an upholstery layer including channels and a macroencapsulated phase change material within the channels, and an underlying air bladder layer for adjusting the firmness of the mattress assembly in accordance with an embodiment of the present disclosure;

FIG. 2 illustrates cross-sectional view of an exemplary microencapsulated phase change material in accordance with an embodiment of the present disclosure;

FIG. 3 illustrates cross-sectional view of an exemplary air bladder including a sleeve impregnated with microencapsulated phase change material in accordance with an embodiment of the present disclosure;

FIG. 4 illustrates a cross-sectional view of a mattress assembly including an upholstery layer including channels and a macroencapsulated phase change material within the channels, and an underlying modular cylindrical foam spring layer for adjusting the firmness of the mattress assembly in accordance with an embodiment of the present disclosure; and

FIG. 5 illustrates a perspective view of an exemplary modular cylindrical foam spring layer including a bucket assembly defining a cavity and a plurality of cylindrical foam springs in the cavity in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION

Disclosed herein are mattress assemblies including macroencapsulated phase change materials, wherein a bulk amount of the phase change material on the order of tens to thousands of grams per square foot are provide in a preformed capsulate, which is in direct contrast to microencapsulated phase change materials that encapsulate milligram quantities per square foot of the phase change materials in a microcapsule. Also, microencapsulated phase change materials in mattress assemblies typically require a substrate in which it can be disposed, e. g., foam, fiber or the like. In the present disclosure, the macroencapsulated phase change material are self-supporting and can define a complete layer or portions thereof.
In one embodiment, the mattress assemblies include an upholstery layer (i.e., the uppermost layer) including a foam layer defining a plurality of channels provided therein, wherein a macroencapsulated phase change material including the preformed capsulate is provided in one or more of the channels. The mattress assemblies further include a pump configured to exhaust air from the upholstery layer during periods of use or non-use. Exhausting air from the upholstery layer including the macroencapsulated phase change material during use can remove heat and extend cooling effectiveness by prolonging the transition time from the solid phase to the liquid phase. Additionally, exhausting air during periods of non-use can decrease the transition time from the liquid phase back to the solid phase such that effective and maximum cooling is provided during subsequent periods of use, e.g., during a typical sleep cycle of about 8 hours or longer. In this manner, the heat dissipation from the phase change material in the liquid phase can be accelerated.
In one or more embodiments, the mattress assemblies further include an underlying air bladder system or an underlying modular foam spring system that can further includes phase change material. As will be described in greater detail below, the air bladder system or an underlying modular foam spring system can be utilized to adjust the firmness of the mattress assembly as well as assist with cooling. In the case of the air bladder system, the pump can also be utilized to adjust pressure within selected ones of the air bladders via a manifold, which can be used to selectively vary firmness of the mattress assembly. Likewise, firmness properties of the mattress assemblies can be altered with the modular foam spring system by selectively placing foam springs having a desired firmness level at different locations.
The upholstery layer including the plurality of channels with at least a portion of the channels including the macroencapsulated bulk phase change material(s) can be located at or proximate to a sleeping surface and may span the length and/or width of the sleeping surface or a portion thereof to define one or more zones. By way of example, the upholstery layer can be used to define a topper layer that is typically positioned at or in close proximity to the sleeping surface. The phase change material can be a single-phase change material or mixtures of phase change materials, wherein the mixtures can include different phase change materials having similar or different transition temperatures. Moreover, each macroencapsulated phase change material can be formed of a sealed capsulate disposed within a given channel, which can have similar or different amounts of the phase change materials depending on its location relative to the sleeping surface, and/or the macroencapsulated phase change material can have similar and/or different shapes and/or dimensions.
As used herein, the term “macroencapsulated phase change material” refers to encapsulation of a bulk amount of the PCM blend in a preformed capsulate, which can be on the order of at least about 50 grams per square foot or more. In contrast, microencapsulated phase change material, which have traditionally been integrated into foam layers and fabric to provide the cooling effect in mattress applications, are typically on the order of few grams or milligrams per square foot. Microencapsulated phase change material generally includes a polymeric or inorganic shell configured to encapsulate and prevent leakage of a relatively small amount of phase change material during use, wherein the shell is substantially spherically-shaped having diameters of several nanometers to several microns. In the present disclosure, the upholstery layer includes macroencapsulated phase change material within a preformed capsulate having an interior volume significantly larger than microencapsulated phase change materials. The preformed capsulate can be configured in a variety of forms and shapes. The macroencapsulated phase change material can span the entire layer of a mattress or a portion thereof, wherein the preformed capsulate contains a bulk amount of the phase change material, which depending on the intended application and configuration, can encapsulate hundreds to thousands of grams of the phase change material and further include additional materials, e.g., blends thereof, foams, fibers, thermally conductive additives, fire retardants, dyes, and the like.
As used herein, the term “transition time” generally refers to an amount of time for transition of the phase change material per unit cell volume to a different phase, e.g., solid phase to liquid phase or vice versa. For example, an end user would feel cool as a solid phase change material absorbs heat from the end user during a sleep cycle, wherein the phase change material would transition from a solid state to a liquid state. In contrast, subsequent to use, the liquid phase change material can transitions back to the solid state to provide a cooling effect during the subsequent sleep cycle. In the present disclosure, the macroencapsulated phase change material or materials provided within the channel can be calculated to provide cooling or heating from about 30 minutes to about 8 hours or longer. The terms solid phase or liquid phase and solid state or liquid state, respectively, are intended to be interchangeable and equivalent
For the purposes of the description hereinafter, the terms “upper”, “lower”, “top”, “bottom”, “left,” and “right,” and derivatives thereof shall relate to the described structures, as they are oriented in the drawing figures. The same numbers in the various figures can refer to the same structural component or part thereof. Additionally, the articles “a” and “an” preceding an element or component are intended to be nonrestrictive regarding the number of instances (i.e. occurrences) of the element or component. Therefore, “a” or “an” should be read to include one or at least one, and the singular word form of the element or component also includes the plural unless the number is obviously meant to be singular.
Spatially relative terms, e.g., “beneath,” “below,” “lower,” “above,” “upper,” and the like, can be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures.
The following definitions and abbreviations are to be used for the interpretation of the claims and the specification. As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having,” “contains” or “containing,” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, a mixture, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but can include other elements not expressly listed or inherent to such composition, mixture, process, method, article, or apparatus.
As used herein, the term “about” modifying the quantity of an ingredient, component, or reactant of the invention employed refers to variation in the numerical quantity that can occur, for example, through typical measuring and liquid handling procedures used for making concentrates or solutions. Furthermore, variation can occur from inadvertent error in measuring procedures, differences in the manufacture, source, or purity of the ingredients employed to make the compositions or carry out the methods, and the like.
It will also be understood that when an element, such as a layer, region, or substrate is referred to as being “on” or “over” another element, it can be directly on the other element or intervening elements can also be present. In contrast, when an element is referred to as being “directly on” or “directly over” another element, there are no intervening elements present, and the element is in contact with another element.
Referring now to FIG. 1 , there is depicted a cross-sectional view of a mattress assembly generally designated by reference numeral 10 in accordance with an embodiment of the present disclosure. The mattress assembly 10 includes an upholstery layer 12, an air bladder assembly layer 14 underlying the upholstery layer, and one or more underlying base foam layers 16, 18, (two of which are shown).
The upholstery layer 12 generally includes a foam or fiber body 20 defining one or more channels 22. The illustrated upholstery layer 12 overlies the air bladder assembly layer 14. The upholstery layer 12 is generally parallelepiped-shaped having a length (L) dimension and a width (W) dimension that can be configured to approximate the length and width dimension of the mattress assembly 10. The illustrated upholstery layer 14 generally has a thickness equal to or less than 6 inches in one or more embodiments, a thickness equal to or less than 5 inches in other embodiments, or a thickness equal to or less than 4 inches in still other embodiments. In other embodiments, the thickness is greater than or equal linch.
In one or more embodiments, the channels 22 are uniformly spaced apart within a selected surface and parallel to one another extending transversely from one side to another side of the width dimension (W) as shown. In one or more other embodiments, the channels 22 can longitudinally extend from one side to another side of the length dimension (not shown) and/or are non-uniformly spaced apart and/or are not parallel to one another. In still other embodiments, the channels can be non-uniform and define zones.
Each of the channels 22 has a depth that is an entirety or a fraction of a total thickness of the upholstery layer 12. In one or more embodiments, the depth of the channels is about 90% or less than the thickness of the upholstery layer 12. In one or more other embodiments, the depth of the channels is about 80% or less than the thickness of the upholstery layer 12, and in still one or more embodiments, the depth of the channels is about 70% or less than the thickness of the upholstery layer 12. In one or more embodiments, each of the channels 22 can have the same depth or have different depths depending on the intended application. In one or more embodiments, different depths can be employed to provide zoning. Similarly, the channels 22 can be selectively located to provide zoning to correspond to the head region, the lumbar region, and/or the leg and foot region of the mattress assembly 10. In the case of channel 22 extending the entirety of the thickness of the upholstery layer 12, the foam or fiber 20 would be in the form of strips.
Disposed within each of the channels 22 is a macroencapsulated phase change material 24. As shown more clearly in FIG. 2 , the macroencapsulated phase change material 24 includes a bulk amount of a phase change material or mixture of phase change materials 26 sealingly disposed within a preformed capsulate 28. Although the macroencapsulated phase change material 24 can span the entire channel 22, it should be apparent that the macroencapsulated phase change material 24 can be configured to span a portion thereof. Advantageously, the bulk phase change material 26 within the macroencapsulated phase change material 24 provides extended cooling as needed to an end user of the mattress assembly 10. As shown, each macroencapsulated phase change material 24 provided within a given channel 22 is tubular-shaped and is seated on a bottom surface of a respective one of the channels 22. The macroencapsulated phase change material 24 can have a dimension that is a fraction of the depth of the channel 22 such that a space 30 is provided above the macroencapsulated phase change material 24 relative to the uppermost surface 32 of the upholstery layer 12 as shown and/or can completely fill a respective channel 22. In one or more embodiments, the macroencapsulated phase change material 24 provided in channels 22 are at different depths (not shown), so that the macroencapsulated bulk phase change material 24 can be activated at different times, e.g., the macroencapsulated bulk phase change material 24 closest to the sleeping surface (i.e., closest to the uppermost surface 32 of upholstery layer 12) will activate earlier than the macroencapsulated phase change material farther away from the sleeping surface.
In one or more embodiments, the upholstery layer 12 can be formed from viscoelastic foam or non-viscoelastic foam depending on the intended application. The foam itself can be of any open or closed cell foam material including without limitation, latex foams, natural latex foams, polyurethane foams, combinations thereof, and the like. The density of the upholstery layer 12 can be within a range of 1 to 8 lb/ft³in some embodiments, and 2 to 4 lb/ft³in other embodiments. The hardness is within a range of about 7 to 28 pounds-force in some embodiments, and less than 15 pounds-force in other embodiments. In one or more embodiments, the cover layer can be configured as a quilt panel or a convoluted foam.
The air bladder system layer 14 underlying the upholstery layer 12 generally includes a foam encased bucket assembly 40 including a base layer 42 and a perimeter side rail assembly 44 about the base layer 42 to define a well or cavity. The well or cavity provides a space in which one or more air bladders 46 are inserted, five of which are shown. In the illustrated mattress assembly 10, the plurality of air bladders 46 are generally positioned at about the head, lumbar, and upper leg or thigh regions. However, it should be apparent that the air bladders 46 can be located at any one or combinations thereof of the foot, head, and lumbar regions as well as portions within the region depending on the intended application.
As shown more clearly in FIG. 3 , each air bladder 46 further includes a sleeve 48 including a phase change material, which can include a foam or fiber sleeve impregnated with a microencapsulated phase change material or a capsulate sleeve filled with a bulk amount of phase change material. Optionally, the air bladders 46 could include an upper form layer as opposed to a sleeve affixed thereto, wherein the upper form layer includes microencapsulated phase change material.
The individual air bladders 46 can be fluidly connected to one another and in fluid communication with a pump 50 or can be fluidly connected directly to the pump 50 via a manifold 52 such that pressure within each individual air bladder 46 can be independently controlled or a combination thereof. As such, some of the plurality of air bladders can be fluidly coupled to one another to define a zone whereas the other air bladders can be configured as different zones, wherein pressure within the different zones can be adjusted to provide the bedding system with zones of variable firmness, which can be desirable for supporting different portions of the body for the end user.
The pump 50 can be provided with a pneumatic line to selectively regulate and adjust pressure in one or more of the air bladders 46 as desired, which can be used to adjust the firmness of the mattress assembly 10. An operable valve such as a pressure relief valve, electronically actuated valve, or the like can be inline and/or at the inlets and/or outlets to the air bladders 46 to permit selective inflation and exhaustion of air to/from air bladders to adjust the internal pressure and locally adjust firmness levels in the bedding system. The air bladders 46 themselves can include interconnecting internal or external fluid passageways so as to adjust the pressure therein.
In one or more embodiments, the pump 50 can include additional conduits 54 positioned to exhaust air from the upholstery layer. In this manner, the pump 50 can be used to accelerate phase transition of the macroencapsulated phase change material within the channels of the upholstery layer 12 via heat dissipation.
A control unit 60 is electronically connected to the pump 50 as well as the actuator valves and can be programmed to adjust the pressures within the air bladders 46 as desired. The control unit 60 includes control circuitry that generates signals to control the inflation and deflation of one or more air bladders 46, which can include a plug coupled to an electrical outlet (not shown) to receive local power, which in the United States could be standard 110 V, 60 Hz AC electric power supplied through a power cord. It should be understood that alternate voltage and frequency power sources may also be used depending upon where the product is sold and the local standards used therein. Control circuitry further includes power circuitry that converts the supplied AC power to power suitable for operating various circuit components of control circuitry.
Turning now to FIG. 4 , there is depicted a cross sectional view of a mattress assembly 100 including the upholstery layer 112 as previously described. The upholstery layer 112 includes a foam or fiber body 120 defining one or more channels 122. The illustrated upholstery layer 112 overlies a modular cylindrical foam spring layer 114. The upholstery layer 12 is generally parallelepiped-shaped having a length (L) dimension and a width (W) dimension that can be configured to approximate the length and width dimension of the mattress assembly 100.
Disposed within each of the channels 122 is a macroencapsulated phase change material 124. Each macroencapsulated phase change material 24 provided within a given channel 122 can be tubular-shaped and is seated on a bottom surface of a respective one of the channels 122. The macroencapsulated phase change material 124 can have a dimension that is a fraction of the depth of the channel 122 such that a space 130 is provided above the macroencapsulated phase change material 124 relative to the uppermost surface of the upholstery layer 12 as shown and/or can completely fill a respective channel 122. In one or more embodiments, the macroencapsulated phase change material 124 provided in channels 122 are at different depths (not shown), so that the macroencapsulated bulk phase change material 124 can be activated at different times, e.g., the macroencapsulated bulk phase change material 124 closest to the sleeping surface (i.e., closest to the uppermost surface of upholstery layer 112) will activate earlier than the macroencapsulated phase change material farther away from the sleeping surface.
As shown in FIG. 5 , the modular cylindrical foam spring layer 114 includes a plurality of individual and removable cylindrical foam springs 140, 142 within a foam bucket assembly 170, wherein cylindrical foam springs 140, 142 include a central aperture 144 in which a macroencapsulated phase change material 146 is disposed and solid core cylindrical foam springs that do not include a central aperture and instead are solid foam bodies, respectively. Interstices between adjacent cylindrical spring provide increased airflow through the mattress assembly 100. Optionally, the macroencapsulated phase change material 146 can be disposed in one or more of the interstices in addition to one or more of the central apertures 144 of the cylindrical foam spring. Alternatively, the macroencapsulated phase change material 146 can be provided only in one or more of the interstices and not in any of the central apertures.
Similar to the mattress assembly of FIG. 1 , mattress assembly 100 further includes a foam layer 116 including a pump 150 and a conduit 152 underlies the modular cylindrical foam layer 114 and is configured to exhaust air from the upholstery layer 112 as previously described. One or more additional foam layers 118, one of which is shown, can be provided as a base layer.
Phase change materials are relatively inexpensive whereas the cost to manufacture prior art microencapsulated phase change materials are relatively high since the encapsulation material has a high surface area relative to the amount of phase change material contained within each cell. In contrast, the encapsulated bulk amounts of a phase change material of the present disclosure provide a markedly higher volume of phase change material(s) within the capsulate material that lowers the surface area of the capsulate material relative to the amount of phase change material, thereby providing a significant cost reduction. In this manner, instead of milligrams to grams of phase change material within a given layer as is currently done in the prior art, the present invention advantageously provides the capability of utilizing hundreds of grams or pounds of phase change material within a given layer as may be desired for different applications. The increased amount of phase change material within the plurality of channels in the layer can be configured to extend the effective solid to liquid or liquid to solid transition time of the phase change material throughout an entire sleep cycle of 8 hours or more, which is unlike prior art microencapsulated phase change layers that generally provide an effective transition time of a few minutes to about 30 minutes.
Although a tubular shape is generally referenced in the Figures, the macroencapsulated phase change material is not intended to be limited to any particular geometric shape. In one or more embodiments, the encapsulated bulk phase change material can be composed of a single sealed cell. In one or more other embodiments, the encapsulated bulk phase change material can be formed of multiple interconnected fluidly connected to one another, and in one or more other embodiments, the macroencapsulated phase change material can be formed of multiple discrete cells. In the case of a single sealed cell, interconnected cells, or multiple individual discrete cells, the cellular volumes are generally greater than 1 cm³.
Optionally, the macroencapsulated phase change material can include a permeable material that can be saturated with the phase change material or materials while in a liquid state, inserted into an opening of the capsulate material, and then sealed. The use of the permeable material would help the layer keep its shape when the phase change material or materials changes to its liquid state. Without the addition of a permeable material such as an open cell foam when the phase change material or materials changes state to a liquid it would naturally migrate to the side away the pressure of a reclining body. The addition of the foam will insure there is a level of support being provided by the layer even after the phase change material or materials transitions to a liquid state.
In one or more embodiments, the amount of phase change material in the encapsulated bulk phase change material 30 is at least 50 grams per square foot of surface area, greater than about 100 grams per square foot in other embodiments, and greater than about 500 grams per square foot in still other embodiments.
The capsulate material can be formed of a flexible material such as polyethylene or the like as the capsulate material, which can be filled with the phase change material or a mixture of phase change materials, and optionally foam or other permeable material. Still further, additional material(s) such as flame retardants, antibacterial agents, thermally conductive components, and/or the like can be included within the capsulate. In one or more embodiments, the capsulate material further includes a thermally conductive material.
The particular configuration in terms of cell shape, cell size, cell spatial volume, spacing between cells, fluid connection between linked cells, and the like of the encapsulated bulk phase change material is not intended to be limited. Generally, as it relates to the size, spatial volume, and shape of the cell, the amount of phase change material contained therein is effective to provide a phase transition time to the end user of at least about 30 minutes or greater. In contrast, prior art microencapsulated phase change materials for bedding applications are generally on the order of a few grams or micrograms per square foot.
The capsulate can be formed from two-ply sheets of a resilient and flexible material such as polyethylene and is selected to be compatible with the intended phase change material(s) to be used. As used herein, the term “two-ply” generally refers to two separate sheets, first and second sheets, that are coupled to one another to form the capsulate sheet as described in greater detail below. The individual sheets themselves that define the two-ply capsulate sheet configuration can be formed from a single layer or multiple layers as may be desired for desired strength and resiliency.
Suitable phase change materials that can be incorporated in the preformed capsulate in accordance with various embodiments of the disclosure include a variety of organic and inorganic substances including paraffins; bio-phase change materials derived from acids, alcohols, amines, esters, and the like; salt hydrates; and the like. The particular phase change material or mixtures thereof are not intended to be limited.
Exemplary phase change materials include hydrocarbons (e.g., straight chain alkanes or paraffinic hydrocarbons, branched-chain alkanes, unsaturated hydrocarbons, halogenated hydrocarbons, and alicyclic hydrocarbons), bio-phase change materials derived from fatty acids and their derivatives, (e.g., alcohols, amines, esters, and the like), hydrated salts (e.g., calcium chloride hexahydrate, calcium bromide hexahydrate, magnesium nitrate hexahydrate, lithium nitrate trihydrate, potassium fluoride tetrahydrate, ammonium alum, magnesium chloride hexahydrate, sodium carbonate decahydrate, disodium phosphate dodecahydrate, sodium sulfate decahydrate, and sodium acetate trihydrate), waxes, oils, water, fatty acids, fatty acid esters, dibasic acids, dibasic esters, 1-halides, primary alcohols, aromatic compounds, clathrates, semi-clathrates, gas clathrates, anhydrides (e.g., stearic anhydride), ethylene carbonate, polyhydric alcohols (e.g., 2,2-dimethyl-1,3-propanediol, 2-hydroxymethyl-2-methyl-1,3-propanediol, ethylene glycol, polyethylene glycol, pentaerythritol, dipentaerythritol, pentaglycerine, tetramethylol ethane, neopentyl glycol, tetramethylol propane, 2-amino-2-methyl-1,3-propanediol, monoaminopentaerythritol, diaminopentaerythritol, and tris(hydroxymethyl)acetic acid), polymers (e.g., polyethylene, polyethylene glycol, polyethylene oxide, polypropylene, polypropylene glycol, polytetramethylene glycol, polypropylene malonate, polyneopentyl glycol sebacate, polypentane glutarate, polyvinyl myristate, polyvinyl stearate, polyvinyl laurate, polyhexadecyl methacrylate, polyoctadecyl methacrylate, polyesters produced by polycondensation of glycols (or their derivatives) with diacids (or their derivatives), and copolymers, such as polyacrylate or poly(meth)acrylate with alkyl hydrocarbon side chain or with polyethylene glycol side chain and copolymers comprising polyethylene, polyethylene glycol, polyethylene oxide, polypropylene, polypropylene glycol, or polytetramethylene glycol), metals, and mixtures thereof. Bio-phase change materials have high latent heat, small volume change for phase transition, sharp well-defined melting temperature and reproducible behavior.
The selection of a phase change material will typically be dependent upon a desired transition temperature. For example, a phase change material having a transition temperature slightly above room temperature but below skin temperature may be desirable for mattress applications to maintain a comfortable temperature for a user.
A suitable phase change material can have a phase transition temperature within a range of about 22° to about 36° C. In one or more other embodiments, the transition temperature within a range of about 25° C. to about 30° C. With regard to paraffin phase change materials, the number of carbon atoms of a paraffinic hydrocarbon typically correlates with its melting point. For example, n-octacosane, which contains twenty-eight straight chain carbon atoms per molecule, has a melting point of 61.4° C. whereas n-tridecane, which contains thirteen straight chain carbon atoms per molecule, has a melting point of −5.5° C. According to an embodiment of the disclosure, n-octadecane, which contains eighteen straight chain carbon atoms per molecule and has a melting point of 28.2° C., is particularly desirable for mattress applications. Additionally, coconut fats and oils can be suitable used as a phase change material for mattress applications, which can be selected to have a melting temperature of 19 to 34° C.
Other useful phase change materials include polymeric phase change materials having transition temperatures within a range of about 22° to about 36° C. in one or more embodiments, and a transition temperature within a range of about 26° to about 30° C. in other embodiments. A polymeric phase change material may comprise a polymer (or mixture of polymers) having a variety of chain structures that include one or more types of monomer units. Polymeric phase change materials may include linear polymers, branched polymers (e.g., star branched polymers, comb branched polymers, or dendritic branched polymers), or mixtures thereof. A polymeric phase change material may comprise a homopolymer, a copolymer (e.g., terpolymer, statistical copolymer, random copolymer, alternating copolymer, periodic copolymer, block copolymer, radial copolymer, or graft copolymer), or a mixture thereof. As one of ordinary skill in the art will understand, the reactivity and functionality of a polymer may be altered by addition of a functional group such as, for example, amine, amide, carboxyl, hydroxyl, ester, ether, epoxide, anhydride, isocyanate, silane, ketone, and aldehyde. Also, a polymer comprising a polymeric phase change material may be capable of crosslinking, entanglement, or hydrogen bonding to increase its toughness or its resistance to heat, moisture, or chemicals.
According to some embodiments of the disclosure, a polymeric phase change material may be desirable as a result of having a higher molecular weight, larger molecular size, or higher viscosity relative to non-polymeric phase change materials (e.g., paraffinic hydrocarbons). In addition to providing thermal regulating properties, a polymeric phase change material may provide improved mechanical properties (e.g., ductility, tensile strength, and hardness).
For example, polyethylene glycols may be used as the phase change material in some embodiments of the disclosure. The number average molecular weight of a polyethylene glycol typically correlates with its melting point. For instance, a polyethylene glycol having a number average molecular weight range of 570 to 630 (e.g., Carbowax 600) will have a melting point of 20° to 25° C., making it desirable for mattress applications. Further desirable phase change materials include polyesters having a melting point in the range of 22° to 40° C. that may be formed, for example, by polycondensation of glycols (or their derivatives) with diacids (or their derivatives).
According to some embodiments of the disclosure, a polymeric phase change material having a desired transition temperature may be formed by reacting a phase change material (e.g., an exemplary phase change material discussed above) with a polymer (or mixture of polymers). Thus, for example, n-octadecylic acid (i.e., stearic acid) may be reacted or esterified with polyvinyl alcohol to yield polyvinyl stearate, or dodecanoic acid (i.e., lauric acid) may be reacted or esterified with polyvinyl alcohol to yield polyvinyl laurate. Various combinations of phase change materials (e.g., phase change materials with one or more functional groups such as amine, carboxyl, hydroxyl, epoxy, silane, sulfuric, and so forth) and polymers may be reacted to yield polymeric phase change materials having desired transition temperatures.
Table 1 provides a list of exemplary commercially available phase change materials and the corresponding metal point (Tm) suitable for use in mattress applications described herein.

TABLE 1

				Melting
Material	Supplier	Type	Form	point, Tm

0500- Q28	Phase Change	Functionalized	Bulk, Macro-	28° C. (82° F.)
BioPCM	Energy	BioPCM	encapsulated
	Solutions
PureTemp 28	PureTemp LLC	Organic	Bulk	28° C. (82° F.)
RT27	Rubitherm	Organic	Bulk	28° C. (82° F.)
	GmbH
Climsel C28	Climator	Inorganic	Bulk	28° C. (82° F.)
RT 30	Rubitherm	Organic	Bulk	28° C. (82° F.)
	GmbH
RT 28 HC	Rubitherm	Organic	Bulk	28° C. (82° F.)
	GmbH
A28	PlusICE	Organic	Bulk	28° C. (82° F.)
MPCM 28	Microtek	Organic	Micro-	28° C. (82° F.)
			encapsulated
MPCM 28D	Microtek	Organic	Micro-	28° C. (82° F.)
			encapsulated
Latest 29 T	TEAP	Inorganic	Bulk	28° C. (82° F.)
0500- Q29	Phase Change	Functionalized	Bulk, Macro-	29° C. (84° F.)
BioPCM	Energy	BioPCM	encapsulated
	Solutions
29 C. ° Infinite R	Insolcorp	Inorganic	Macro-	29° C. (84° F.)
			encapsulated
savE HS 29	Pluss	Inorganic	Bulk	29° C. (84° F.)
savE OM 29	Pluss	Organic	Bulk	29° C. (84° F.)
savE FS 29	Pluss	Organic	Bulk	29° C. (84° F.)
PureTemp 29	PureTemp LLC	Organic	Bulk	29° C. (84° F.)
TH 29	TEAP	Inorganic	Bulk	29° C. (84° F.)
A29	PlusICE	Organic	Bulk	29° C. (84° F.)
PCM-HS29P	SAVENRG	Inorganic	Bulk	29° C. (84° F.)
CrodaTherm ™ 29	Croda	Organic	Bulk	29° C. (84° F.)
	International
	Plc
0500- Q30	Phase Change	Functionalized	Bulk, Macro-	30° C. (86° F.)
BioPCM	Energy	BioPCM	encapsulated
	Solutions
S30	PlusICE	Inorganic	Bulk	30° C. (86° F.)
savE OM 30	Pluss	Organic	Bulk	31° C. (88° F.)
savE FS 30	Pluss	Organic	Bulk	31° C. (88° F.)
RT 31	Rubitherm	Organic	Bulk	31° C. (88° F.)
	GmbH
0500- Q32	Phase Change	Functionalized	Bulk, Macro-	32° C. (90° F.)
BioPCM	Energy	BioPCM	encapsulated
	Solutions
savE OM 32	Pluss	Organic	Bulk	32° C. (90° F.)
Climsel C32	Climator	Inorganic	Bulk	32° C. (90° F.)
S32	PlusICE	Inorganic	Bulk	32° C. (90° F.)
A32	PlusICE	Organic	Bulk	32° C. (90° F.)
PCM-OM32P	SAVENRG	Organic	Bulk	32° C. (90° F.)

Also, the phase change material according to one or more embodiments can have a latent heat that is at least about 40 Joules/gram (J/g), at least about 50 J/g in other embodiments, and at least about 60 J/g in still other embodiments. As used herein, the term “latent heat” can refer to an amount of heat absorbed or released by a substance (or mixture of substances) as it undergoes a transition between two states. Thermal energy can be stored or removed from a phase change material, and the phase change material typically can be effectively recharged by a source of heat or cold. By selecting an appropriate phase change material, a multi-component fiber can be designed for use in any one of numerous products.
The phase change material can include a mixture of two or more substances (e.g., two or more of the exemplary phase change materials discussed above). By selecting two or more different substances (e.g., two different paraffinic hydrocarbons) and forming a mixture thereof, a temperature stabilizing range can be adjusted over a wide range to extend the cooling effect over a longer period of time. For example, octadecane can be used as the primary phase change material to which a small amount of phase change material(s) having a lower carbon content (e.g., C₁₆, C₁₇) can be used to lower the melting point, which can make the mixture less hard at room temperature. According to some embodiments of invention, the mixture of two or more different substances may exhibit two or more distinct transition temperatures or a single modified transition temperature.
During manufacture of the layer, the phase change material in the raw form may be provided as a solid in a variety of forms (e.g., bulk form, powders, pellets, granules, flakes, microencapsulates, and so forth) or as a liquid in a variety of forms (e.g., molten form, dissolved in a solvent, and so forth).
As noted above, a bulk amount of the phase change material(s) is provided within the capsulate, which generally consists of a flexible pouch partially filled with or without air. In one or more embodiments, the phase change material can be injected directly into a cell and subsequently sealed using a hardener or a sealing adhesive. In other embodiments, recesses are formed in a carrier sheet and subsequently filled with the desired phase change material. A cover sheet is the coupled applied to the carrier sheet. The coupling can be provided with an applied adhesive or can be thermally fused. In one or more embodiments, the phase change material can be maintained above its melting temperature during the injection.
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to make and use the invention. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

Claims

What is claimed is:

1. A mattress assembly comprising:

an upholstery foam layer proximate to a sleeping surface of the mattress assembly comprising a plurality of channels and a macroencapsulated phase change material including a sealed capsulate and a bulk amount of phase change material within the sealed capsulate provided within at least one or more of the channels; and

an underlying layer including a pump and a plurality of conduits configured to exhaust air from the upholstery layer.

2. The mattress assembly of claim 1, wherein the macroencapsulated phase change material further comprises a permeable material infused with the phase change material or a mixture of phase change materials within the sealed capsulate.

3. The mattress assembly of claim 1, wherein the permeable material comprises foam.

4. The mattress assembly of claim 1, wherein the phase change material comprises coconut oil.

5. The mattress assembly of claim 1, wherein the phase change material or the mixture of phase change materials has a melting point in a range of about 22° C. to about 36° C.

6. The mattress assembly of claim 1 further comprising an additional layer underlying the upholstery layer comprising a plurality of air bladders fluidly coupled to the pump and configured to change a pressure within the plurality of air bladders.

7. The mattress assembly of claim 6, wherein each of the air bladders comprises a sleeve about at least a portion of a periphery, wherein the sleeve comprises microencapsulated phase change material therein.

8. The mattress assembly of claim 1 further comprising an additional layer underlying the upholstery layer comprising a bucket assembly defining a cavity, and a plurality of removable cylindrical foam springs in the cavity, wherein one or more of the cylindrical foam springs comprises a central aperture and a tubular shaped macroencapsulated phase change material disposed within the central aperture.

9. The mattress assembly of claim 1, wherein the plurality of cylindrical foam springs are configured to provide the mattress assembly with different firmness zones.

10. The mattress assembly of claim 1, wherein the macroencapsulated phase change materials partially fill the channels to create a space within the channel.