Method for producing an extruded mesh body for a vehicle seat and the article produced thereby

Abstract

A body made from a plurality of extruded polymer filaments randomly oriented and interconnected to form a three-dimensional mesh structure. The body is elongated in an extrusion or longitudinal direction. First zones of the extruded polymer filaments have a first density and second zones of the extruded polymer filaments have a second density less than the first density. The first and second zones are separated by boundaries or transition regions. A method of making a seat cushion with extruded polymer filaments having different zones with different densities and hardness characteristics by controlling the speed of a plurality of tug belts in a cooling bath.

Description

Reference to related applications

[0001] This application claims priority to U.S. Patent Application Serial No. 18 / 962,730, filed on November 27, 2024, and also claims the benefit of U.S. Provisional Application Serial No. 63 / 612,215, filed on December 19, 2023. This application also claims priority to Danish Patent Application No. PA202470196, filed on July 18, 2024. The disclosures of these are incorporated herein by reference in their entirety. Technical field

[0002] An extruded body of polymer filaments manufactured by a process that forms a cushion of varying densities across the width of the extruded body. Short description of the drawings Fig. Figure 1 is a schematic diagram of a plastic extrusion line. Fig. Figure 2 is a plan view of a variable speed tractor section having a plurality of tractor belts arranged across the extrusion perpendicular to the extrusion direction. Fig. 3 is a front plan view of a seat back cushion. Fig. 4 is a plan view of a seat cushion. Fig. Figure 5 is a cross-sectional view taken through the extruded preform. Fig. Figure 6 is a perspective view of a partially disassembled vehicle seat showing the frame and seat cover. Detailed description

[0003] Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the various described embodiments. However, it will be apparent to one of ordinary skill in the art that the various described embodiments may be practiced without these specific details. In other instances, well-known methods, procedures, components, circuits, and networks have not been described in detail in order not to unnecessarily obscure aspects of the embodiments.

[0004] It is to be understood that the disclosed embodiments are merely exemplary, and that various and alternative forms are possible. The figures are not necessarily to scale; some features may be exaggerated or reduced 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 embodiments according to the disclosure.

[0005] “One or more” includes a function performed by one element, a function performed by more than one element, for example in a distributed manner, multiple functions performed by one element, multiple functions performed by multiple elements, or any combination of the above.

[0006] It should also be understood that although the terms "first," "second," etc., are used in some instances herein to describe various elements, those elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, a first contact could be referred to as a second contact, and similarly, a second contact could be referred to as a first contact, without departing from the scope of the various described embodiments. The first contact and the second contact are both contacts, but they are not the same contact.

[0007] The terminology used in the description of the various embodiments described herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various embodiments described and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It is also to be understood that the term "and / or," as used herein, refers to and includes any and all possible combinations of one or more of the associated listed elements.It is further understood that the terms "includes", "including", "comprises" and / or "comprising", when used in this specification, specify the presence of the stated features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0008] Referring to Fig. Figure 1 schematically illustrates an extrusion line 10 for forming a preform strip 12 from polymer filaments 14. An extruder 12 receives resin beads 16 from a resin hopper 14, which are melted in the extruder 12 and then fed to a die head 22. The die head 22 extrudes the polymer filaments 14, which are then fed through a forming hopper 24. The forming hopper 24 deposits the polymer filaments 14 into a cooling tank 26. The polymer filaments 14 are pulled into the cooling tank 26 by a tractor section 28 at a controllable speed. As the preform strip is drawn into the cooling tank 26, the polymer filaments 14 are welded together as they are first cooled by the water in the cooling tank 26. A roller 30 in the cooling tank 26 pulls the preform strip 12 further into the cooling tank 26.A discharge conveyor 32 discharges the preform strip 12 from the cooling tank 26, while a vibrating table 34 shakes the preform strip 12 to remove water from the preform strip 12. A return water trough 36 collects the water as it drains from the preform strip 12. A fan 38 is directed over the return water trough 36 to cool the water as it flows back into the cooling tank 26.

[0009] The polymer filaments 14 comprise strands, fibers, or strips that are welded, bonded, or melted and formed into a three-dimensional mesh structure. The preform strip 12 comprises an intermediate preform for producing a plurality of vehicle seat cushions, which are subsequently cut into individual seat cushions and formed into a predetermined shape.

[0010] The polymer resin 18 comprises LLDPE or HDPE, which are added to the resin hopper 20 in the form of resin beads, ground polymer resin, or the like.

[0011] The cooling tank 26 is filled with water or an aqueous coolant solution for polymers.

[0012] The drag section 28, described in more detail below, pulls the polymer filaments 14 in a longitudinal direction, which is the extrusion direction, which is the direction in which the polymer strands 14 flow from the die head 22 and the forming hopper 24.

[0013] Referring to Fig. 2 is the Fig. 1 is shown to include a plurality of tug belts 40a-40e that are controlled to move at a variable speed relative to each other, thereby forming zones or areas with different hardness characteristics. Fig. In Figure 2, a seat base image 42 is superimposed on the view of the tug belts 40a-40e. The seat base image 42 represents the seat to be formed when the preform strip is cut into discrete seat cushion pieces, which are then formed in a mold into the shape of the illustrated seat cushion.

[0014] The seat cushion image 42, shown in phantom lines, includes a first hardness zone 44 and a second hardness zone 46. A first boundary 48 is formed between the first hardness zone 44 and the second hardness zone 46. A third hardness zone 50 and the second hardness zone 46 form a second boundary 52 therebetween. As shown in Fig. 2, the first boundary 48 and the second boundary 52 are not perpendicular to the longitudinal direction in which the belts move or to the extrusion direction, but instead converge from the front portion of the seat base image 42 to the rear portion of the seat base image 42.

[0015] It should be understood that boundaries 48 and 52 may be curved or arranged in a wide variety of angular orientations relative to the longitudinal direction to achieve the desired variation in the hardness profile in predetermined zones or regions of the molded seat cushion. The first boundary 48 and the second boundary 52 may extend completely across the preform strip 12 or may extend partially across the preform strip 12. The boundary may alternatively be referred to as a transition region between different hardness zones.

[0016] At the inlet end of the tug belt section 26, a first speed arrow 54 is shown, graphically representing the different speeds at which the various tug belts 40a-40e act on the preform strip 12. The size of the first speed arrows 54 corresponds to the speed at which the respective tug belts are moved.

[0017] A second speed arrow 56 is in Fig. 2 above the first speed arrow 54 and shows that at a subsequent point in time the speed of the tractor belts 40e-40e is changed in order to locally change the bulk density of the preform strip 12. Similarly, a third speed arrow 58, which is shown in Fig. 2 above the second speed arrow 56, additional speed changes can be made to again change the bulk density of the preform strip 12. The length of each speed arrow 52, ​​54, 56 is varied to indicate that the relative speed of the tug belts 40a-40e changes as the polymer filaments 20 are pulled through the tug section 26.

[0018] The bulk density of the cushion is controlled by the tug belts 40a-40e. Bulk density is not the same as filament density, which is the density of a single strand. The spacing of the strands is controlled by the speed at which the tug belts 40a-40e pull the strands into the cooling tank 24 or the water bath. The bulk density in a respective zone of the seat base increases as the speed of the tug conveyor belts 40a-40e decreases. Conversely, the bulk density in a respective zone of the seat base decreases as the speed of the tug conveyor belts 40a-40e increases. There is an upper limit to the difference in speed differences as to how fast adjacent tug belts can move. If the speed difference is too great, some of the filaments may become overstretched or break, become thin, or lose their bonding sites.The extent of bulk density variation in the cushion is limited, but can approach 60% variation from one zone to another.

[0019] The motors 60a-60e are variable speed motors controlled by a controller 62. The controller 62 is programmed to vary the speed of the motors individually and the movement of the tug belts 40a-40e to match or correspond to the specified bulk density of the seat cushion zones to be produced.

[0020] Referring to Fig. Figure 3 shows the preform strip in cross-section across the width of the preform strip 12 to demonstrate the variations in bulk density across the preform strip. Different bulk densities are illustrated by the relative looseness and compaction in the different zones.

[0021] Referring to Fig. 4 and Fig. 5 is a seat backrest 64 in Fig. 4 and a seat cushion 66 in Fig. 5, which includes a soft zone, or area, 68, and three different hard zones, or areas, 70, 72, and 74, with different hardness values. For example, the hardness of the soft zone is 1.2 kPa and the bulk density is 1.8 kg / m 3 The three different hard zones have a hardness ranging from 1.2 kPA to 23.1 kPA and a bulk density ranging from 1.8 kg / m 3 up to 5.8 kg / m 3 suffices.

[0022] Referring to Fig.6, a vehicle seat assembly 74 is shown including a seat frame 76, a seat cover 78, a seat back cushion 64, and a seat base cushion 66. The seat frame 76 and cover 78 are provided in a wide range of styles and designs. The seat back cushion 64 and the seat base cushion 66 are polymer filaments that are first formed into the preform strip 12, which is divided into separate cushions or seat pads and molded into shape before being assembled to the vehicle seat assembly 74. The preform strip 12 is divided into a plurality of seat back cushions 64 or seat base cushions 66, each of which is mounted to one of a plurality of seat frames 76 and covered with one of a plurality of seat covers 78.

[0023] An article comprising a body of a plurality of extruded polymer filaments 14 randomly oriented and interconnected to form a three-dimensional network structure 12, the body 12 being elongated in a longitudinal direction and comprising first zones 42 comprising the extruded polymer filaments 14 having a first bulk density and second zones 46 comprising the extruded polymer filaments 14 having a second bulk density less than the first bulk density.

[0024] The article described in the previous paragraph may include one or more of the following additional features: The article according to one or more of the above clauses, comprising the first zones 42 and the second zones 44 defining at least one boundary 48 or transition areas between the first zones 42 and the second zones 44 that extend at least partially across the body 12.

[0025] The article according to one or more of the above clauses, comprising first zones 42 and second zones 44 defining at least one boundary 48 between the first zones and the second zones extending completely across the body 12.

[0026] The article according to one or more of the above clauses, comprising at least one boundary 48 between the first zones 42 and the second zones 44 extending at an angle less than perpendicular relative to the longitudinal direction in which the body is moved.

[0027] The article according to one or more of the above clauses, comprising at least one boundary 48 between the first zones 42 and the second zones 44 that is curved.

[0028] The article according to one or more of the above clauses, comprising the body 12 comprising a plurality of connected intermediate preforms 12, each of the intermediate preforms 12 being adapted to be separated and formed into a seat cushion 64, 66.

[0029] A seat assembly 64, 66 including a seat frame, a seat cover, a seat back cushion 64, and a seat base cushion 66. The body 12 includes a plurality of extruded polymer filaments 14 randomly oriented and bonded together to form an intermediate preform 12 including first zones 44 of the extruded polymer filaments 14 having a first bulk density and second zones 46 of the extruded polymer filaments 14 having a second bulk density less than the first bulk density, the intermediate preform 12 being shaped to form the shaped back cushion 64 and the seat base cushion 66.

[0030] The seat assembly described in the previous paragraph may include one or more of the following additional features: The seat assembly according to one or more of the above clauses, comprising first zones 42 and second zones 44 defining at least one boundary 48 or transition region between the first zones 42 and the second zones 44 that extends at least partially across the body 12.

[0031] The seat assembly according to one or more of the above clauses, comprising first zones 42 and second zones 44, the at least one boundary 48 between the first zones 42 and the second zones 44 extending completely across the body 12.

[0032] The seat assembly according to one or more of the above clauses, comprising at least one boundary 48 between the first zones 42 and the second zones 44 that is curved.

[0033] A method comprising melting a polymer resin 18 to form a molten polymer, extruding the molten polymer through a die head 22 to form extruded polymer filaments 14, and forming and bonding the extruded polymer filaments 14 into a strip of filaments 12 comprising a predetermined cross-section. The method further comprises pulling the strip of filaments 12 into a cooling tank 26 in a longitudinal direction with a plurality of drag belts 40a-40e arranged transversely to the longitudinal direction, each of the drag belts 40a-40e moving one of a plurality of portions of the strip of filaments 12 in the longitudinal direction.The plurality of tug belts 40a-40e are controlled to move one of the plurality of sections of the strip of filaments 12 at a different speed relative to others of the plurality of tug belts 40a-40e to locally control the bulk density of the plurality of sections of the strip of filaments 14 across a width of the strip of polymer filaments 12.

[0034] The method described in the previous paragraph may have one or more of the following additional features: The method according to one or more of the above clauses, comprising the method further comprising forming the strip of filaments 12 transversely to the longitudinal direction to form a plurality of seat cushion preforms 64, 66.

[0035] The seat assembly of one or more of the above paragraphs, comprising a method further comprising forming the plurality of seat cushion preforms 64, 66 into a contoured shape of a seat cushion.

[0036] The seat assembly according to one or more of the above clauses, comprising a method wherein the polymer resin 18 is a thermoplastic polymer such as LLDPE or HDPE.

[0037] The seat assembly according to one or more of the above clauses, comprising a method further comprising mounting the strip of filaments 12 comprising a seat cushion 64, 66 to a seat frame.

[0038] The seat assembly according to one or more of the above clauses, comprising a method further comprising covering the seat cushion 64, 66 with a seat cover.

[0039] The seat assembly according to one or more of the above clauses, comprising being manufactured according to the method.

[0040] While exemplary embodiments are described above, these embodiments are not intended to describe all possible forms according to the disclosure. In this regard, 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. Furthermore, the features of the various implementing embodiments may be combined to form further embodiments according to the disclosure. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 18 / 962,730

[0001] US 63 / 612,215

[0001]

Claims

[1] An article comprising: a body of a plurality of extruded polymer filaments randomly aligned and interconnected to form a three-dimensional network structure, the body being elongated in a longitudinal direction and comprising first zones comprising the extruded polymer filaments having a first density and second zones comprising the extruded polymer filaments having a second density less than the first density. [2] The article of claim 1, wherein the first zones and the second zones define at least one boundary between the first zones and the second zones that extends at least partially across the body. [3] The article of claim 2, wherein the at least one boundary between the first zones and the second zones is curved. [4] The article of claim 2, wherein the at least one boundary between the first zones and the second zones extends at an angle less than perpendicular relative to the longitudinal direction. [5] The article of claim 1, wherein the first zones and the second zones define at least one boundary between the first zones and the second zones that extends completely across the body. [6] The article of claim 1, wherein the body comprises a plurality of intermediate preforms, each of the intermediate preforms being adapted to be severed and formed into a seat cushion. [7] A seat assembly comprising: a seat frame; a seat cover; and a body comprising a plurality of extruded polymer filaments randomly aligned and bonded together to form an intermediate preform comprising first zones of the extruded polymer filaments comprising a first density and second zones of the extruded polymer filaments comprising the extruded polymer filaments comprising a second density less than the first density, the intermediate preform being formed to form a shaped seat cushion. [8] The seat assembly of claim 7, wherein the first zones and the second zones define at least one boundary between the first zones and the second zones that extends at least partially across the body. [9] The seat assembly of claim 7, wherein the first zones and the second zones define at least one boundary between the first zones and the second zones that extends completely across the body. [10] The seat assembly of claim 9, wherein the at least one boundary between the first zones and the second zones is curved. [11] A method including: Melting a polymer resin to form a molten polymer; Extruding the molten polymer through a die head to form extruded polymer filaments; Forming and joining the extruded polymer threads into a strip of filaments comprising a predetermined cross-section; pulling the strip of filaments into a cooling bath in a longitudinal direction with a plurality of drag belts arranged transversely to the longitudinal direction, the drag belts each moving one of a plurality of portions of the strip of filaments in the longitudinal direction; and Controlling the plurality of tractor belts to move one of the plurality of sections of the strip of filaments at different speeds relative to the others of the plurality of tractor belts to locally control a density of the plurality of sections of the strip of filaments across a width of the strip of polymer filaments. [12] The method of claim 11, further comprising: Cutting the strip of filaments transversely to the longitudinal direction to form a plurality of seat cushion preforms. [13] The method of claim 12, further comprising: Forming the plurality of seat cushion preforms into a contoured shape of a plurality of seat cushions. [14] The method of claim 13, further comprising: Mounting the plurality of seat cushions each to one of a plurality of seat frames. [15] The method of claim 13, further comprising: Covering the variety of seat cushions each with one of a variety of seat covers. [16] The method of claim 11, wherein the polymer resin is HDPE. [17] The method of claim 11, wherein the polymer resin is a thermoplastic polymer. [18] The method of claim 11, wherein the polymer resin is LLDPE. [19] A strip of polymer filaments produced by the process of claim 11.

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