WO2023075888A1

WO2023075888A1 - Method of bonding seat trim cover to foam cushion

Info

Publication number: WO2023075888A1
Application number: PCT/US2022/040199
Authority: WO
Inventors: Baolong SHANG; Yufeng Feng; Yujie DU; Shaoying Chen; Yue ZUO
Original assignee: Lear Corporation
Priority date: 2021-10-28
Filing date: 2022-08-12
Publication date: 2023-05-04
Also published as: CN116039473A

Abstract

The application relates to a method of bonding seat trimcover to foam cushion. A vehicle seat trim assembly includes a trim cover assembly configured to be disposed over a seat cushion, the trim cover assembly having an A-side forming an occupant support, and a B-side opposite the A-side corresponding to the seat cushion; and a heating wire disposed on a layer of the trim cover assembly. The layer of the trim cover assembly is positioned inward from the occupant support surface. The heating wire forms a predetermined pattern on the layer and includes a core wire with a hot-melt adhesive wrapped thereon. Upon electrification of the heating wire, the core wire generates heat to melt the hot-melt adhesive and bond the trim cover assembly and the seat cushion.

Description

METHOD OF BONDING SEAT TRIM COVER TO FOAM CUSHION

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to Chinese Patent Application No. 202111264663.0, filed on October 28, 2021, the disclosure of which is hereby incorporated in its entirety by reference herein.

TECHNICAL FIELD

[0002] The present application is directed to a method of bonding a seat trim cover to a foam cushion, and more particularly, using a wire with a hot melt adhesive disposed thereon to bond the trim cover to the foam cushion.

BACKGROUND

[0003] Vehicle seats having seat bottoms and seatbacks typically include foam cushions disposed on a seat frame to provide support to vehicle occupants. The cushions include a trim cover disposed thereon to provide an aesthetically pleasing appearance for the occupant support surface. Various methods have been contemplated for attaching trim covers to the foam cushion, for example stitching or mechanical fasteners. However, durability of the attachment mechanisms and flexibility in design capability (e.g., due to stitch patterns) are often compromised.

SUMMARY

[0004] According to one or more embodiments, a vehicle seat trim assembly includes a trim cover assembly configured to be disposed over a seat cushion, the trim cover assembly having an A- side forming an occupant support, and a B-side opposite the A-side corresponding to the seat cushion; and a heating wire disposed on a layer of the trim cover assembly. The layer of the trim cover assembly is positioned inward from the occupant support surface. The heating wire forms a predetermined pattern on the layer and includes a core wire with a hot-melt adhesive disposed thereon. Upon electrification of the heating wire, the core wire generates heat to melt the hot-melt adhesive and bond the trim cover assembly and the seat cushion.

[0005] According to at least one embodiment, the predetermined pattern may be configured to form a heat supply to heat to an occupant seated on the occupant support surface. In other embodiments, the predetermined pattern may be based on bond locations between the trim cover assembly and the seat cushion. In at least one embodiment, the layer may be a heating mat secured to the trim cover assembly. In further embodiments, the heating wire may be secured to a surface of the layer facing towards the A-side of the trim cover assembly. In some further embodiments, the layer may be porous such that the hot-melt adhesive flows therethrough to bond to the seat cushion. In some embodiments, the heating wire may further include an insulation layer between the core wire and the hot-melt adhesive. Furthermore, the insulation layer may be a perfluoroalkoxy polymer.

[0006] According to one or more embodiments, a method of forming a seat assembly includes providing a cushion, providing a trim cover assembly having a layer, and securing a heating wire including a core wire and a hot-melt adhesive thereon to the layer of the trim cover assembly or the cushion. The method further includes positioning the trim cover assembly over the cushion, electrifying the heating wire to generate heat from the core wire and melting the hot-melt adhesive to bond the trim cover assembly and the cushion together.

[0007] According to at least one embodiment, securing the heating wire to the layer may form a heating mat, and the method may further include securing the heating mat to the trim cover assembly such that the heating wire is disposed on a surface of the heating mat where the heating wire is between the layer and an occupant support surface of the trim cover assembly. In one or more embodiments, securing the heating wire includes positioning the heating wire according to a predetermined pattern. In at least one embodiment, the method may further include cooling the hot- melt adhesive to form bonds between the trim cover assembly and the cushion. In one or more embodiments, positioning the trim cover assembly over the cushion may include pressing the trim cover assembly on the cushion to shape the trim cover assembly. In certain embodiments, securing the heating wire to the layer may include securing the heating wire to a B-side of the layer, the B- side configured contact with the cushion. In some embodiments, the heating wire further may include an insulation layer between the core wire and the hot-melt adhesive. In further embodiments, electrifying the heating wire may include heating the core wire to a first temperature corresponding to melting the hot-melt adhesive. Furthermore, the method may include, after the trim cover assembly is bonded to the cushion, electrifying the heating wire to heat the core wire to a second temperature, lower than the first temperature, to provide heat to an occupant support surface without melting the hot-melt adhesive. In some embodiments, the first temperature may be 150 to 300 degrees C.

[0008] According to one or more embodiments, a method of forming a seat assembly includes providing a cushion, providing a trim cover assembly comprising a trim layer forming an occupant support surface on an A-side, and securing a heating wire including a core wire coated with a hot-melt adhesive between the trim cover assembly and the cushion. The method further includes positioning the trim cover assembly over the cushion, electrifying the heating wire to heat the core wire such that the hot-melt adhesive melts, and cooling the hot- melt adhesive to form bonds between the trim cover assembly and the cushion.

[0009] In at least one embodiment, securing the heating wire may include securing the heating wire to a heating mat, and attaching the heating mat to a B-side of the trim layer such that the heating wire is sandwiched between the heating mat and the B-side of the trim layer.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG. 1 illustrates a perspective view of a representative vehicle seat, according to an embodiment;

[0011] FIG. 2A illustrates a front view of a seat cushion, according to an embodiment;

[0012] FIG. 2B illustrates a front view of a heating mat for a seat cushion, according to an embodiment;

[0013] FIG. 3 illustrates a schematic cross-sectional view of a heating wire, according to an embodiment; and

[0014] FIG. 4 illustrates a schematic cross-sectional view of a heating wire, according to another embodiment. DETAILED DESCRIPTION

[0015] As required, detailed embodiments of the present disclosure are disclosed herein; however, it is to be understood that the disclosed embodiments are merely examples of the disclosure that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present disclosure.

[0016] Except in any examples, or where otherwise expressly indicated, all numerical quantities in this description indicating amounts of material or conditions of reaction and/or use are to be understood as modified by the word "about" in describing the broadest scope of the invention. Practice within the numerical limits stated is generally preferred. As used herein, the term “about” means that the amount or value in question may be the specific value designated or some other value in its neighborhood. The term “about” or “generally” denoting a certain value is intended to denote a range within +/- 5% of the value. As one example, the phrase “about 100” denotes a range of 100+/- 5, i.e. the range from 95 to 105. When the term “about” or “generally” is used, it can be expected that similar results or effects according to the invention can be obtained within a range of +/- 5% of the indicated value. It should also be appreciated that integer ranges (e.g., for measurements or dimensions) explicitly include all intervening integers. For example, the integer range 1-10 explicitly includes 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10. Similarly, the range 1 to 100 includes 1, 2, 3, 4, . . . 97, 98, 99, 100. Similarly, when any range is called for, intervening numbers that are increments of the difference between the upper limit and the lower limit divided by 10 can be taken as alternative upper or lower limits. For example, if the range is 1.1. to 2.1 the following numbers 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, and 2.0 can be selected as lower or upper limits.

[0017] Also, unless expressly stated to the contrary: percent, “parts of,” and ratio values are by weight; the term “polymer” includes “oligomer,” “copolymer,” “terpolymer,” and the like; molecular weights provided for any polymers refers to weight average molecular weight unless otherwise indicated; the description of a group or class of materials as suitable or preferred for a given purpose in connection with the invention implies that mixtures of any two or more of the members of the group or class are equally suitable or preferred; description of constituents in chemical terms refers to the constituents at the time of addition to any combination specified in the description, and does not necessarily preclude chemical interactions among the constituents of a mixture once mixed; the first definition of an acronym or other abbreviation applies to all subsequent uses herein of the same abbreviation and applies mutatis mutandis to normal grammatical variations of the initially defined abbreviation; and, unless expressly stated to the contrary, measurement of a property is determined by the same technique as previously or later referenced for the same property.

[0018] It is also to be understood that this invention is not limited to the specific embodiments and methods described below, as specific components and/or conditions may, of course, vary. Furthermore, the terminology used herein is used only for the purpose of describing particular embodiments of the present invention and is not intended to be limiting in any way.

[0019] It must also be noted that, as used in the specification and the appended aspects, the singular form “a,” “an,” and “the” comprise plural referents unless the context clearly indicates otherwise. For example, reference to a component in the singular is intended to comprise a plurality of components.

[0020] Throughout this application, where publications are referenced, the disclosures of these publications in their entireties are hereby incorporated by reference into this application to more fully describe the state of the art to which this invention pertains.

[0021] According to embodiments of the present disclosure, a method of bonding a trim cover to a foam cushion of a seat assembly includes wrapping a heating wire with a hot melt adhesive, placing the heating wire between the foam and trim, and electrifying the heating wire to melt the hot melt adhesive and bond the trim cover to the foam.

[0022] Referring now to the figures, where like numerals are used to designate like structure throughout to the drawings, a schematic vehicle seat assembly in accordance with at least one embodiment of the present disclosure is generally shown at by seat assembly 100 in FIG. 1.

[0023] FIG. 1 illustrates a schematic view of a seat assembly 100. The seat assembly 100 may be adapted for use in a motor vehicle, such as a car or truck, or may be used with other seat assemblies including aircraft, theater seats or any suitable seat assemblies, and the discussion of the seat assembly 100 in a vehicle is not intended to be limiting. While the seat assembly 100 is illustrated in Figure 1 to be a bucket seat assembly, it should be understood that the principles of the present disclosure are applicable to other types of seat assemblies, such as bench, captain, and other types of seat assemblies.

[0024] As shown in FIG. 1, the vehicle seat assembly 100 includes a seatback 110 and a seat bottom 120, connected to form seat assembly 100 for supporting an occupant in the vehicle. The seatback 110 may be pivotally mounted to seat bottom 120. The seat bottom 120 may be mounted on a seat frame (not shown) which can be removably secured to the vehicle floor. In some embodiments, the seatback 110 may include a head restraint 160.

[0025] In at least one embodiment, each of the seatback 110 and seat bottom 120 include foam cushion 130, 140, respectively. The foam cushion 130, 140 can be conventionally secured to a seat frame (not shown) by any method generally known in the art. Each foam cushion 130, 140 may be one or more foam parts, joined together to form the seat component. For example, the seatback 110 foam cushion 130 may include side bolster portions (shown as side bolsters 132), a lower bolster, or any other components to meet a desired design. The foam cushions 130, 140 can have any suitable size and be formed from any suitable configuration of components. In one or more embodiments, the foam cushions 130, 140 form a concave shape for the corresponding occupant seating surfaces , with the concavity of the foam cushions 130, 140 improving occupant comfort and aesthetic styling of the seat assembly 100. The seatback foam cushion 130 and the seat bottom foam cushion 140 can independently comprise any suitable comfort foam material such as, but not limited to, a suitable resilient polymer, and can independently be formed in any suitable manner. For example, the foam cushions 130, 140 may be formed of conventional polyurethane foam, soy-based foam, silicone, thermoplastic olefins, thermoplastic urethanes, and/or natural oil-based expanded polyurethanes, soy-based polyurethane, polymer fibers, non-woven polyester pads, latex foams and the like. The foam cushions 130, 140 are formed of any suitable comfort material that provides soft resilience as the seat assembly is deflected during use when an occupant is in a seated position. In at least one embodiment, suitable cushion materials will have a density of 1.5 to 4.5 pcf, in another embodiment of 2.0 to 3.75 pcf, and in yet other embodiments of 2.7 to 3.0 pcf. Density of the cushion material can be measured by ASTM test method No. D3574. Hereinafter, although foam cushions 130, 140 will be referred to, this is not intended to be limiting, and will be used to collectively refer to any cushion component of the seat assembly 100.

[0026] Referring to FIGS. 2A-B, the seat assembly 100 also includes trim cover assembly 150 adapted to engage the foam cushions 130, 140 in a covering relationship and based on the concavity and surface contours defined by the foam cushions 130, 140. The trim cover assembly 150 may include any number of separate components to form the desired aesthetic of the seat assembly 100. The trim cover assembly 150 includes a trim cover 152, which may comprise any material commonly known in the art. By way of example, some of the known materials include cloth, fabric, leather, synthetic leather, vinyl, synthetic suede, non-woven fabric, or combinations thereof (fabric-to-fabric, leather-to-leather, fabric-to-leather, leather-to-fabric, etc.), or polymers of sufficient quality and thickness for use in seat trim applications. Polymer trim materials may include a flexible closed cell polymer skin material such as polyvinyl, polyvinyl chloride (PVC), thermoplastic olefin (TPO), or thermoplastic urethane (TPU). The trim cover layer 152 has an A-side that defining an occupant seating surface for the seatback 110, and seat bottom 120, respectively. The occupant seating surface on the A-side of the trim cover 152 is the external surface visible to the occupant. The trim cover layer 152 may have additional layers disposed inward of the A-side, positioned between the trim cover layer 152 and the cushion 130, 140. Additionally, materials for use as layers of the trim cover assembly 150 may include a spacer layer 154 (shown in FIG. 2B), such as a foam, plastic, or spacer material, to name a few. Any suitable foam may be a polyurethane, polyethylene, polypropylene, polystyrene, reticulated, or memory foam. Any suitable spacer material can be used, such as, but not limited to, Mueller Textil type, Guilford Mills, polyester knit, faux suede, polyester spacer material, or other suitable material. In some embodiments, the spacer layer may comprise a two-layer construction of scrim or mesh, and another component. The trim cover assembly 150 may include any suitable number of other layers (for example, a mesh or reinforcing materials, such as fiberglass or nylon) on the back of the trim cover 152 for increasing strength without increasing rigidity. The inner surface of the innermost layer of the trim cover assembly 150 (opposite the A-side of the trim cover 152) will be referred to as the B- side 153 of the trim cover assembly 150, and refers to the innermost layer of the trim cover assembly 150, which may in certain embodiments, be the trim cover 152, in other embodiments, the spacer layer 154, or other suitable layer of the trim cover assembly 150. [0027] It should be understood that the cushion 130 for the seatback 110 can differ from the cushion 140 of the seat bottom 120. Likewise, it should be understood that the trim cover assembly 150 for the seat back 110 can differ from the trim cover assembly 150 for the seat bottom 120.

[0028] According to various embodiments, the trim cover assembly 150 is bonded to cushions using a heating wire 200, and a method of bonding the trim cover assembly 150 to the foam cushions includes electrifying the heating wire 200 to melt a hot-melt adhesive 220 thereon to bond the trim cover assembly to the cushions. The hot-melt adhesive is included as a layer on a core wire or on an insulation layer on the core wire, with the heating wire being positioned between the foam cushion and the trim cover assembly 150 per the desired bond pattern or heating pattern (e.g., in heated seats to provide heat to the occupant support surface). By using a heating wire, the contours of the foam cushion can be realized for heating, and the trim cover 152 can be bonded to the foam cushion per the surface curves to support unique aesthetic seat cushion designs such as concave seats. Using a heating wire to bond the trim cover and seat cushion improves cost and efficiency of the seat assembly process, and allows the cushion and trim cover assembly to be reworked and/or repaired upon re-melting of the hot-melt adhesive to allow detachment of the trim cover assembly from the foam cushions. Details regarding the heating wire and bonding between the trim cover assembly and cushions will be provided with reference to FIGS 2A-B, and 3-4.

[0029] Referring to FIG. 2A-B, the seat assembly 100 further includes one or more heating wires 200 (collectively referred to hereinafter as the heating wire 200, which is not intended to be limiting to a single heating wire) disposed on the B-side 153 of the trim cover assembly 150, or alternatively, disposed on the surface of the cushions 130, 140 (not shown), or any other suitable seat component, such as a heating mat (see FIG. 2B), to be covered by the trim cover assembly 150 to form the seat assembly 100. As such, the heating wire 200 is generally disposed between the trim layer 152 and the surface of the cushion 130, 140. In certain embodiments, heating wires 200 may be included on both the trim cover assembly 150 and the foam cushions 130, 140, as based on design considerations for bonding. The heating wire 200 may be configured as one or more heating wires 200 forming a pattern as based on the desired bonding, or may be configured as a heating mat 158 on a separate layer with a group of heating wires 200 on the component of the seat assembly 100 to be covered by the trim cover assembly 150. Furthermore, although described hereinafter as being positioned on the trim cover assembly 150 (as shown in FIG. 2A), the heating wire 200 may similarly be disposed on the cushions 130, 140 and used in a similar manner to bond the cushions 130, 140 with the trim cover assembly, and discussion of the heating wire 200 on the trim cover assembly 150 is not intended to be limiting. Moreover, the securing of the heating wire 200 to the trim cover assembly 150 may similarly be considered for attachment to a separate layer 154 (as shown in FIG. 2B) (hereinafter forming the heating mat 158) or on the cushions 130, 140 (not shown) such that the trim cover assembly 150 can be secured thereto for bonding. The heating mat 158 may be, in some embodiments, a felt material adhered to the foam cushions 130, 140 or the 13- side of the trim cover assembly 150 by a suitable mechanism, such as, but not limited to, a pressure sensitive adhesive or water based glue, sewing, or mechanical fasteners. Additionally, reference to the heating wire 200 being disposed on the B-side 153 of the trim cover assembly 150 is not intended to be limiting to any particular layer of the trim cover assembly 150, and the heating wire 200 may be on the B-side 153 of any suitable layer of the trim cover assembly 150. For example, the heating wire 200 may be disposed on the B-side 153 of the trim cover 152. In other embodiments, the heating wire 200 may be disposed on the B-side 153 of the spacer layer 154 (as shown in FIG. 2B forming the heating mat 158). Generally, the heating wire 200 is disposed on the innermost surface of the trim cover assembly 150, opposite the A-side, as per the surface that contacts the cushions 130, 140 upon covering the cushions 130, 140 with the trim cover assembly 150. The heating wire 200 may be secured to the B-side 153 by any suitable mechanism, including, but not limited to, stitching, weaving into a mesh support for stitching onto a surface, adhesives, hot-press, tagging gum, fine pine attachment, or other fastening mechanisms to attach the heating wire 200 against the B-side 153.

[0030] In certain embodiments, referring again to the embodiments shown in FIGS. 2A-B, the heating wire 200 may be positioned in a predetermined pattern as based on forming a heating mat 158 for a heated seat with the trim cover assembly 150. For example, the heating mat 158 may be a felt material, a non-woven fabric, a foam material (e.g., polyurethane foam), or other suitable layer to form the heating mat 158 with the heating wire secured to a first side of the heating mat 158, the first side corresponding to the side of the heating mat 158 facing the trim cover 152, with the heating mat 158 positioned between the trim cover 152 and the cushion 130, 140. In certain further embodiments, the heating wire 200 may be disposed on a layer of a suitable porous material (e.g., a woven scrim or grid cloth having a suitable pore size based on the adhesive used) to allow the hot- melt adhesive 220 to flow therethrough for bonding the heating mat 158 with the cushions 130, 140. However in other embodiments (not shown), the heating wire 200 may be selectively located as based on forming desired bonds between the trim cover assembly 150 and the cushions 130, 140 to sufficiently bond the trim cover assembly 150 to the cushions 130, 140. For example, where the cushions 130, 140 are forming a concave seat assembly, the bond locations may be selected to contour the trim cover assembly 150, with the heating wire 200 locations based on improving the arrangement of the trim cover assembly 150 against the curves and contours of the seat cushions 130, 140. The heating wire 200 is provided between the trim cover assembly 150 and the cushions 130, 140 to facilitate bonding of the trim cover assembly 150 with the cushions 130, 140 via electrification of the heating wire 200 via an external power source 300 to attach the trim cover assembly 150 to the cushions 130, 140 via bonds formed by an adhesive (e.g., a hot-melt adhesive). The external power source 300 may be any suitable power source as based on the rating of the heating wire 200. In some embodiments, the voltage range may be from 50-200 V, and may be supplied by a transformer (e.g., a 380V transformer). The trim cover assembly 150 may also be mechanically secured to the foam cushions 130, 140 by mechanical fasteners (e.g., tie-downs) at other points of the foam cushions 130, 140, or may be fixed on the seat frame (not shown).

[0031] Referring to FIG. 3, the heating wire 200 is shown according to an embodiment. The heating wire 200 includes a core wire 210 being capable of being electrified to generate heat via a thermoresistive property, and a hot-melt adhesive layer 220 coated or otherwise disposed on the core wire 210 which melts upon heating of the core wire 210 to bond the trim cover assembly 150 with the cushions 130, 140. The core wire 210 may be any suitable wire that can be heated via application of electricity, including, but not limited to carbon fiber, stainless steel, Cu-based metal, Ni-chrome, and other similar materials. The core wire 210 may have any suitable diameter, but in certain embodiments, the core wire has a diameter of 0.1 to 2 mm, in other embodiments, 0.2 to 1.5 mm, and in yet other embodiments, 0.3 to 1.0 mm. The core wire 210 may have, in some embodiments, a resistance of 0.1 to 20 Q/m of wire, in other embodiments, 1.5 to 15 Q/m of wire, and in yet other embodiments 5 to 10 Q/m of wire. In one or more embodiments, the resistance may be 6.5 to 8.5 Q/m of wire. In certain embodiments, the core wire may reach 100 to 320 degrees C, in other embodiments 125 to 310 degrees C, and in yet other embodiments, 150 to 300 degrees C. In certain embodiments, the temperature of the core wire 210 upon electrification may be based on the hot-melt adhesive layer 220 coated thereon, such that the electrification causes the core wire 210 to heat to a sufficient temperature to melt the hot-melt adhesive 220. Moreover, the cushions 130, 140 are heat resistant to the temperature reached by the core wire 210 to melt the hot-melt adhesive and allow the cushions 130, 140 to bond to the trim cover assembly 150, without causing any structural changes to the cushions 130, 140. The hot-melt adhesive layer 220 may be any suitable material capable of melting and curing (e.g., cooling) to form a bond between the adjacent layers (e.g., the trim cover assembly 150 and the cushions 130, 140). As such, the hot-melt adhesive layer 220 may have a melting point in certain embodiments of 90 to 130 degrees C. In certain embodiments, the hot-melt adhesive layer 220 may be a thermoplastic polyurethane, a polyamide, a polyethylene, a polyester, or an ethylene vinyl acetate copolymer. After bonding the trim cover assembly 150 to the cushions 130, 140 and curing, the hardness of the hot-melt adhesive may be 70 to 75 Shore A in certain embodiments, 71 to 74 Shore A in other embodiments, and 72 to 73 Shore A in yet other embodiments.

[0032] Referring to FIG. 4, the heating wire 200 is shown according to another embodiment. The heating wire 200 further includes an insulation layer 230 between the core wire 210 and the hot- melt adhesive layer 220. The insulation layer 230 may be any suitable insulation material, such as, but not limited to a high temperature resistance insulation like fluorinated thermoplastic insulations (e.g., PFA/MFA), with the high temperature resistance being defined as being able to maintain the structural integrity in environments up to 200-350 degrees C. In embodiments where the heating wire 200 includes the insulation layer 230, the heating wire 200 may be heated to a first temperature to melt the hot-melt adhesive 220 and bond the trim cover assembly 150 and the cushions 130, 140, and to a second temperature thereafter, less than the first, to heat a heating mat 158 configuration of the heating wire 200 to form a heated seat for an occupant without affecting the bonds of the cured hot-melt adhesive. For example, in certain embodiments, the melting point of the hot-melt adhesive is around 110 degrees C, while the insulation layer has a melting point around 320 degrees C. As such, the heating temperature is controlled to bond the trim cover assembly with the foam cushion at the low first temperature, and can then be heated for heated seat applications to a suitable temperature (e.g., 55 to 65 degrees C) for heating the occupant support surface. The heating mat 158 configuration of the heating wire 200 may include attaching the heating wire onto a layer of the trim cover assembly, for attachment to the trim cover assembly with the heating mat 158 positioned between the trim cover 152 and the cushion 130, 140. In certain further embodiments, the heating wire 200 may be positioned on a side of the heating mat 158 facing the trim cover 152, and the trim layer may be a suitable porous material (e.g., a grid cloth) to allow the hot-melt adhesive 220 to flow therethrough for bonding the heating mat 158 with the cushions 130, 140.

[0033] In other embodiments, the heating wire 200 may be heated to bond the trim cover assembly 150 and the cushions 130, 140, and thereafter disconnected from the power supply 300, such that the core wire 210 remains between the trim cover assembly 150 and the cushions 130, 140 in the finished seat assembly 100. In embodiments where the heating wire 200 is disconnected from the power supply 300 after bonding is complete, the core wire 210 may be reheated to melt the adhesive and allow separation of the trim cover assembly 150 and the cushions 130, 140 in situations such as for repairs.

[0034] In at least one embodiment, the heating wire 200 may form bonds at 1% to 80% of the surface area cushion and/or trim cover assembly. In other embodiments, the bonds may be at 10% to 70% of the surface area, and in yet another embodiment, at 20% to 60% of the surface area. The minimum contact area for including the heating wire 200 depends on the desired design and bond locations of the trim layer on the cushions and the desired strength of the bond. In some embodiments, to achieve a durable bond, the minimum contact area may be 5%, in other embodiments, 10% to 95%, and in yet another embodiment, 15% to 90%. In certain embodiments, the bond strength or peel strength of the trim cover assembly 150 to the foam cushions 130, 140 via the heating wire 200 may vary depending on characteristics of the design and desired heating, such as the contact area defined by and the spacing of the heating wire 200. Furthermore, the bond or peel strength may depend on characteristics of the adhesive, such as the density, and spacing of the adhesive, as well as the processing parameters. The bond strength (or interchangeably peel strength) may be measured by various test methods. In one or more embodiments, the bond and/or peel strength of the trim cover assembly 150 to the foam cushions 130, 140 is at least 0.4 N per centimeter, as measured by ASTM D903, and in other embodiments, at least 0.5 N per centimeter. In certain embodiments, the bond and/or peel strength is 1 N per centimeter to 20 N per centimeter, in other embodiments 1.5 N per centimeter to 15 N per centimeter, and in yet another embodiment 1.75 N per 5 centimeter to 12.5 N per centimeter. In at least one embodiment, the bond strength may be characterized by sustaining a minimum of 30,000 egress/ingress cycles as measured by ASTM321. In another embodiment, the bond strength may be characterized by sustaining 30,000 to 70,000 egress/ingress cycles, and in yet another embodiment, 40,000 to 60,000 egress/ingress cycles.

[0035] According to one or more embodiments, a method of bonding a trim cover assembly to foam cushions is provided. The method includes securing a heating wire having a core wire and a hot-melt adhesive layer thereon to at least one of a cushion or a trim cover assembly. Securing the heating wire may be via any suitable method, including, but not limited to, hot-pressing, gluing, sewing, weaving, or otherwise incorporating the heating wire on the cushion or on the B-side of the trim cover assembly. In embodiments where the heating wire is hot-pressed, the heating wire may be hot-pressed onto a layer of the trim cover assembly (e.g., fabric). In certain embodiments, the heating wire may be secured to a layer of the trim cover assembly according to a predetermined pattern for forming a heating mat 158 for a heated seat application. Further, the method includes fixing the heating mat 158 onto the foam cushion and/or the trim cover assembly. The heating mat 158 may be fixed such that the heating wire is on a side of the heating mat 158 towards the A- side of the trim cover assembly, with the layer being porous to allow bonding of the heating mat 158 with the cushions upon electrification of the heating wire. In embodiments where the heating wire is secured to a heating mat 158, the heating wire may further include an insulation layer between the core wire and the hot-melt adhesive. In other embodiments, the heating wire may be secured to at least one of the cushion or the trim cover assembly according to the desired bond locations between the cushions and the trim cover assembly. In certain embodiments, the fixing may further include securing the trim cover assembly to the foam cushion by mechanical fasteners to supplement the bonding.

[0036] The method further includes pressing the trim cover assembly against the cushion using a mold tool having a cooling system. The pressing may be according to a desired shape of the foam cushions and/or seating surface for the seat assembly. In certain embodiments, the pressing may be via a hot-stamping process. Upon pressing the trim cover assembly against the cushion, the heating wire is electrified to generate heat and melt the hot-melt adhesive. The heating wire may be electrified to provide heat to the hot-melt adhesive for a minimum of ten seconds, in some embodiments, from 10 to 60 seconds in other embodiments, and 20 to 40 seconds in yet other embodiments. The electrification may be at any suitable voltage to achieve the desired temperature as based on the hot-melt adhesive melting temperature. For example, the voltage applied may be 8 to 90 V in some embodiments. The method further includes initiating the cooling system to cool the hot-melt adhesive to bond the trim cover assembly with the cushions. In certain further embodiments, the heating wire may further be electrified to heat the seating surface, without affecting the hot-melt adhesive or the bonds formed between the trim cover assembly and the cushions.

[0037] According to certain embodiments, a heating wire is used to bond a trim cover assembly with a cushion to form a seat assembly. The heating wire includes a core wire with a hot- melt adhesive disposed thereon. The heating wire may be disposed on a layer of the trim cover assembly and/or on the cushion. In certain embodiments, the heating wire may be provided on a layer to form a heating mat for securing to the trim cover assembly, with the heating wire being positioned between the layer and a trim cover layer of the trim cover assembly. In other embodiments, the heating wire may be provided on a B-side of the innermost layer of the trim cover assembly. The heating wire may be positioned according to a predetermined pattern for forming the heating system for a heated seat, or may be positioned according to the desired bond locations between the trim cover assembly and the cushions.

[0038] The details, designs, variants, aspects and embodiments shown and described herein are applicable to automotive, other vehicular, and non-regulated seating. While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the disclosure. For instance, the shaped protrusions in the layer of leather can have a sewn pattern of thread outlining the protrusions. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the disclosure. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the disclosure. It should be understood that the present disclosure contemplates a seat system or a thoracic region support seating system comprising any combination of features shown in the figures and/or described in the application.

Claims

WHAT IS CLAIMED IS:

1. A vehicle seat trim assembly comprising: a trim cover assembly configured to be disposed over a seat cushion, the trim cover assembly having an A-side forming an occupant support surface, and a B-side opposite the A-side corresponding to a surface of the seat cushion; and a heating wire disposed on a layer of the trim cover assembly, the layer positioned inward from the occupant support surface, and the heating wire forming a predetermined pattern and including a core wire with a hot-melt adhesive disposed thereon, wherein upon electrification of the heating wire, the core wire generates heat to melt the hot-melt adhesive and bond the trim cover assembly to the surface of the seat cushion.

2. The vehicle seat trim assembly of claim 1, wherein the predetermined pattern is configured to form a heat supply to heat to an occupant seated on the occupant support surface upon electrification.

3. The vehicle seat trim assembly of claim 1, wherein the predetermined pattern is based on bond locations between the trim cover assembly and the seat cushion.

4. The vehicle seat trim assembly of claim 1, wherein the layer is a heating mat secured to the trim cover assembly.

5. The vehicle seat trim assembly of claim 4, wherein the heating wire is secured to a surface of the layer facing towards the A-side of the trim cover assembly.

6. The vehicle seat trim assembly of claim 5, wherein the layer is porous such that the hot-melt adhesive flows therethrough to bond to the seat cushion.

7. The vehicle seat trim assembly of claim 1, wherein the heating wire further includes an insulation layer between the core wire and the hot-melt adhesive.

8. The vehicle seat trim assembly of claim 7, wherein the insulation layer is a perfluoroalkoxy polymer.

9. A method of forming a seat assembly comprising: providing a cushion; providing a trim cover assembly having a layer; securing a heating wire including a core wire and a hot-melt adhesive thereon to the layer of the trim cover assembly or the cushion; positioning the trim cover assembly over the cushion; electrifying the heating wire to generate heat from the core wire; and melting the hot-melt adhesive to bond the trim cover assembly and the cushion together.

10. The method of claim 9, wherein securing the heating wire to the layer forms a heating mat, and the method further includes securing the heating mat to the trim cover assembly such that the heating wire is disposed on a surface of the heating mat between the layer and an occupant support surface of the trim cover assembly.

11. The method of claim 10, wherein the layer is porous to allow the hot-melt adhesive to flow therethrough and bond the trim cover assembly to the cushion.

12. The method of claim 9, further comprising cooling the hot-melt adhesive to form bonds between the trim cover assembly and the cushion.

13. The method of claim 9, wherein positioning the trim cover assembly over the cushion includes pressing the trim cover assembly on the cushion to shape the trim cover assembly.

14. The method of claim 9, wherein securing the heating wire to the layer of the trim cover assembly includes securing the heating wire to a B-side of the layer, the B-side configured contact with the cushion.

15. The method of claim 9, wherein the heating wire further includes an insulation layer between the core wire and the hot-melt adhesive.

16. The method of claim 15, wherein electrifying the heating wire includes heating the core wire to a first temperature corresponding to melting the hot-melt adhesive.

17. The method of claim 16, further comprising, after the trim cover assembly is bonded to the cushion, electrifying the heating wire to heat the core wire to a second temperature, lower than the first temperature, to provide heat to an occupant support surface without melting the hot-melt adhesive.

18. The method of claim 16, wherein the first temperature is 150 to 300 degrees C.

19. A method of forming a seat assembly comprising: providing a cushion; providing a trim cover assembly comprising a trim layer forming an occupant support surface on an A-side; securing a heating wire including a core wire coated with a hot-melt adhesive between the trim layer and a surface of the cushion; positioning the trim cover assembly over the cushion; electrifying the heating wire to heat the core wire such that the hot-melt adhesive melts; and cooling the hot-melt adhesive to form bonds between the trim cover assembly and the cushion.

20. The method of claim 19, wherein securing the heating wire between the trim layer and the surface of the cushion includes securing the heating wire to a heating mat, and attaching the heating mat to a B-side of the trim layer such that the heating wire is sandwiched between the heating mat and the B-side of the trim layer.

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