Method of manufacturing an extruded network body for a vehicle seat and article made therefrom

Abstract

The invention relates to a method of manufacturing an extruded mesh body for a vehicle seat and an article made therefrom. A body is made from a plurality of extruded polymer filaments randomly oriented and bonded together to form a three-dimensional network structure. The body is elongated in an extrusion direction or a longitudinal direction. The first region of extruded polymer filaments has a first density and the second region of extruded polymer filaments has a second density less than the first density. The first region and the second region are separated by a boundary or a transition region. A method of making a seat cushion with extruded polymeric filaments, the method making a seat cushion with extruded polymeric filaments having different zones having different density and hardness characteristics by controlling the speed of a plurality of retractor belts in a cooling bath.

Description

[0001] Citation of Related Applications

[0002] This application claims priority to U.S. Patent Application No. 18 / 962,730, filed on November 27, 2024, and also claims the benefit of U.S. Provisional Application 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 applications are hereby incorporated by reference in their entirety. Technical Field

[0003] An extrusion body for polymer filaments, the extrusion body for polymer filaments being made according to a method of forming pads with different densities across the width of the extrusion body. Brief Description of the Drawings

[0005] Figure 1 is a schematic view of a plastic extrusion production line.

[0006] Figure 2 is a front view of a variable-speed traction section having a plurality of traction belts arranged across the extrusion production line perpendicular to the extrusion direction.

[0007] Figure 3 is a front view of a seat back cushion.

[0008] Figure 4 is a top plan view of a seat cushion.

[0009] Figure 5 is a cross-sectional view taken through an extrusion preform.

[0010] Figure 6 is a perspective view of a partially cut-away vehicle seat showing the frame and seat cover. Detailed Description

[0012] Reference will now be made in detail to the 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 so as not to unnecessarily obscure aspects of the embodiments.

[0013] It should be understood that the disclosed embodiments are merely exemplary, and that various alternative forms are possible. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Thus, the specific structural and functional details disclosed herein should not be construed as limiting, but merely as a representative basis for teaching one of ordinary skill in the art to implement the embodiments in accordance with the disclosure in various ways.

[0014] "One or more" includes functions performed by one element, functions performed by more than one element (e.g., in a distributed manner), several functions performed by one element, several functions performed by several elements, or any combination of the above.

[0015] It should also be understood that although the terms first, second, etc. are used in some instances herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first contact may be referred to as a second contact, and similarly, a second contact may be referred to as a first contact, without departing from the scope of the various described embodiments. Both the first contact and the second contact are contacts, but they are not the same contact.

[0016] The terms used in the description of the various embodiments herein are for the purpose of describing particular embodiments only and are not intended to be limiting. As used in the description of the various described embodiments 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 should also be understood that, as used herein, the term "and / or" refers to and encompasses any and all possible combinations of one or more of the associated listed items. It should be further understood that when used in this specification, the terms "comprises", "comprising", "includes", and / or "including" 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.

[0017] Reference Figure 1, schematically shows an extrusion production line 10 for forming a preformed strip 38 for a polymeric filament 20. The extruder 12 receives resin beads 16 from a resin hopper 14, the resin beads 16 are melted in the extruder 12 and then supplied to a die head 18. The die head 18 extrudes the polymeric filament 20, and the polymeric filament 20 is then fed through a forming funnel 22. The forming funnel 22 deposits the polymeric filament 20 into a cooling tank 24. The polymeric filament 20 is pulled into the cooling tank 24 at a controlled speed by a draw section 26. As the preformed strip is pulled into the cooling tank 24, the polymeric filaments 20 are welded together as the polymeric filaments 20 are initially cooled by water in the cooling tank 24. Rolls 28 in the cooling tank 24 further pull the preformed strip 38 into the cooling tank 24. A take-off conveyor 32 removes the preformed strip 38 from the cooling tank 24, while a shaking table 30 shakes the preformed strip 38 to remove water from the preformed strip 38. As water is drained from the preformed strip 38, a water return trough 34 collects the water. A blower 36 is directed over the water return trough 34 to cool the water as it returns to the cooling tank 24.

[0018] The polymeric filament 20 comprises strands, fibers or strips that are welded, glued or melted and reformed into a three-dimensional network structure. The preformed strip 38 comprises an intermediate preform for manufacturing a plurality of vehicle seat cushions, which intermediate preform is subsequently cut into individual seat cushions and molded into a predetermined shape.

[0019] The polymeric resin 16 comprises LLDPE or HDPE provided to the resin hopper 14 in the form of resin beads, ground polymeric resin, etc.

[0020] The cooling tank 24 is filled with water or an aqueous coolant solution for the polymer.

[0021] The draw section 26 is described in more detail below. The draw section 26 pulls the polymeric filament 20 in a longitudinal direction, which longitudinal direction is the extrusion direction, which is the direction in which the polymeric strands 20 flow from the die head 18 and the forming funnel 22.

[0022] Reference Figure 2 , Figure 1 The draw section 26 shown in is shown as comprising a plurality of draw belts 40a - 40e, which plurality of draw belts are controlled to move at different speeds relative to each other so as to form zones or regions having different hardness characteristics. In Figure 2 , a seat base image 42 is superimposed on a view of the draw belts 40a - 40e. The seat base image 42 represents the seat to be formed later, after which the preformed strip is cut into a plurality of discrete seat cushions, which plurality of discrete seat cushions are subsequently formed in a mold into the shape of the seat cushions shown.

[0023] The seat cushion image 42 shown in dashed 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 Figure 2 shown, the first boundary 48 and the second boundary 52 are not perpendicular to the longitudinal direction of the belt movement or the extrusion direction, but converge from the front portion of the seat base image 42 towards the rear portion of the seat base image 42.

[0024] It should be understood that the boundary 48 and the boundary 52 can be curved, or can be oriented at various angles relative to the longitudinal direction to provide a desired change in hardness distribution in a predetermined area or region of the molded seat cushion. The first boundary 48 and the second boundary 52 can extend completely across the preformed strip 38 or can extend partially across the preformed strip 38. The boundary can alternatively be characterized as a transition region between different hardness zones.

[0025] A first speed arrow 54 is shown at the feed end of the drawbar belt section 26. The first speed arrow 54 graphically shows the different speeds at which a plurality of drawbar belts 40a - 40e act on the preformed strip 38. The size of the first speed arrow 54 corresponds to the speed at which the respective drawbar belt moves.

[0026] A second speed arrow 56 is shown Figure 2 above the first speed arrow 54 and represents changing the speed of the drawbar belts 40e - 40e at a subsequent time to locally change the apparent / bulk density in the preformed strip 38. Similarly, Figure 2 a third speed arrow 58 shown above the second speed arrow 56 in shows that additional speed changes can be made to again change the apparent / bulk density of the preformed strip 38. The length of each speed arrow 54, 56, 58 is variable to indicate that the relative speeds of the drawbar belts 40a - 40e change as the polymer filaments 20 are drawn through the drawbar section 26.

[0027] The apparent / bulk density of the padding is controlled by the draw bands 40a - 40e. The apparent / bulk density is different from the filament density, which is the density of individual strands. The spacing of the strands is controlled by the speed at which the draw bands 40a - 40e pull the strands into the cooling box 24 or the water bath. The apparent / bulk density in the corresponding area of the seat base increases as the speed of the draw conveyor belts 40a - 40e decreases. Conversely, the apparent / bulk density in the corresponding area of the seat base decreases as the speed of the draw conveyor belts 40a - 40e increases. There is an upper limit to the difference in speed differences in terms of how fast adjacent draw bands can move. If the speed difference is too large, some filaments may become overstretched or may break, thin out, or lose their bonding positions. The degree of change in the apparent / bulk density in the padding is limited, but the change from one area to another can be close to 60%.

[0028] Motors 60a - 60e are variable speed motors controlled by a controller 62. The controller 62 is programmed to individually change the speed of the motors and the movement of the draw bands 40a - 40e to match or correspond to the specified apparent / bulk density of the area of the seat padding to be manufactured.

[0029] Reference Figure 5 , shows a preformed strip in a cross - section across the width of the preformed strip 38. The apparent / bulk density varies across the preformed strip. Different apparent / bulk densities are characterized by relative looseness and compaction in different areas.

[0030] Reference Figure 3 and Figure 4 , the seat back 64 is shown in Figure 3 and the seat padding 66 is shown in Figure 4 , including a soft zone 68 or area, and two different hard zones or areas 70 and 72 with different hardness values. The hardness of the soft zone is, for example, 1.2 kPA, and the apparent / bulk density is 1.8 kg / m 3 . The hardness of the three different hard zones ranges from 1.2 kPA to 23.1 kPA, and the range of the apparent / bulk density is from 1.8 kg / m 3 to 5.8 kg / m 3 .

[0031] Reference Figure 6, showing a vehicle seat assembly 74, the vehicle seat assembly 74 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 the cover 78 are provided in a wide variety of styles and designs. The seat back cushion 64 and the seat base cushion 66 are polymer filaments, which are first formed into preformed strips 38, the preformed strips 38 are divided into individual cushions or seat pads, and are molded into shape before being assembled into the vehicle seat assembly 74. The preformed strip 38 is divided into a plurality of seat back cushions 64 or seat base cushions 66, and each of the plurality of seat back cushions 64 or seat base cushions 66 is assembled to one of the plurality of seat frames 76 and covered by one of the plurality of seat covers 78.

[0032] An article comprising a body of a plurality of extruded polymer filaments 20 randomly oriented and bonded together to form a three-dimensional network structure 38, wherein the body 38 is elongated in a longitudinal direction and includes a first region 42 and a second region 46, the first region 42 including extruded polymer filaments 20 having a first apparent / bulk density, and the second region 46 including extruded polymer filaments 20 having a second apparent / bulk density less than the first apparent / bulk density.

[0033] The article described in the foregoing paragraphs may include one or more of the following additional features:

[0034] The article according to one or more of the above clauses, including a first region 42 and a second region 44, the first region 42 and the second region 44 defining at least one boundary 48 or transition region between the first region 42 and the second region 44, the at least one boundary 48 or transition region extending at least partially across the body 38.

[0035] The article according to one or more of the above clauses, including a first region 42 and a second region 44, the first region 42 and the second region 44 defining at least one boundary 48 between the first region and the second region, the at least one boundary 48 extending completely across the body 38.

[0036] The article according to one or more of the above clauses, including at least one boundary 48 between the first region 42 and the second region 44, the at least one boundary 48 extending at an angle less than perpendicular to the longitudinal direction of movement of the body.

[0037] The article according to one or more of the above clauses, including at least one boundary 48 between the first region 42 and the second region 44, the at least one boundary 48 being curved.

[0038] An article according to one or more of the above clauses, including a body 38, the body 38 including a plurality of connected intermediate preforms, wherein each of the intermediate preforms is adapted to be separated and molded into seat cushions 64, 66.

[0039] A seat assembly 64, 66 includes a seat frame, a seat cover, a seat back cushion 64 and a seat base cushion 66. The body 38 includes a plurality of extruded polymer filaments 20 randomly oriented and joined together to form an intermediate preform, the intermediate preform including a first region 44 of the extruded polymer filaments 20 and a second region 46 of the extruded polymer filaments 20, the first region 44 of the extruded polymer filaments 20 having a first apparent / bulk density, the second region 46 of the extruded polymer filaments 20 having a second apparent / bulk density less than the first apparent / bulk density, wherein the intermediate preform is molded to form a molded back cushion 64 and a seat base cushion 66.

[0040] The seat assembly described in the preceding paragraph may include one or more of the following additional features:

[0041] A seat assembly according to one or more of the above clauses, including a first region 42 and a second region 44, the first region 42 and the second region 44 defining at least one boundary 48 or transition region between the first region 42 and the second region 44, the at least one boundary 48 or transition region extending at least partially across the body 38.

[0042] A seat assembly according to one or more of the above clauses, including a first region 42 and a second region 44, the first region 42 and the second region 44 defining at least one boundary 48 between the first region 42 and the second region 44, the at least one boundary 48 extending completely across the body 38.

[0043] A seat assembly according to one or more of the above clauses, including at least one boundary 48 between the first region 42 and the second region 44, the at least one boundary 48 being curved.

[0044] A method includes melting a polymer resin 16 to form a molten polymer, extruding the molten polymer through a die 18 to form an extruded polymer filament 20, and shaping and combining the extruded polymer filament 20 into a filament strip 38 having a predetermined cross-section. The method further includes pulling the filament strip 38 in a longitudinal direction into a cooling chamber 24 with a plurality of draw belts 40a - 40e arranged transverse to the longitudinal direction, wherein each of the draw belts 40a - 40e moves one of a plurality of portions of the filament strip 38 in the longitudinal direction. The plurality of draw belts 40a - 40e are controlled to move one of the plurality of portions of the filament strip 38 at a different speed relative to other ones of the plurality of draw belts 40a - 40e to control the apparent / bulk density of the plurality of portions of the filament strip 38 in a zonal manner across the width of the polymer filament strip 38.

[0045] The method described in the foregoing paragraph may include one or more of the following additional features:

[0046] The method according to one or more of the above clauses, further includes cutting the filament strip 38 transverse to the longitudinal direction to form a plurality of seat cushion preforms 64, 66.

[0047] The method according to one or more of the above clauses, further includes molding the plurality of seat cushion preforms 64, 66 into a contoured shape of a seat cushion.

[0048] The method according to one or more of the above clauses, wherein the polymer resin 16 is a thermoplastic polymer such as LLDPE or HDPE.

[0049] The method according to one or more of the above clauses, further includes assembling the filament strip 38 including the seat cushions 64, 66 to a seat frame.

[0050] The method according to one or more of the above clauses, further includes covering the seat cushions 64, 66 with a seat cover.

[0051] A seat assembly manufactured by the method according to one or more of the above clauses.

[0052] While the exemplary embodiments are described above, this does not mean that these embodiments describe all possible forms according to the present disclosure. In this regard, the words used in this specification are descriptive rather than restrictive words, and it should be understood that various changes can be made without departing from the spirit and scope of the present disclosure. Additionally, features of multiple implementation embodiments can be combined to form additional embodiments according to the present disclosure.

Claims

1. A product comprising: A main body, the main body comprising a plurality of extruded polymer filaments, the plurality of extruded polymer filaments being randomly oriented and bonded together to form a three-dimensional mesh structure, wherein the main body is elongated in a longitudinal direction and comprises a first region and a second region, the first region comprising the extruded polymer filaments having a first density, the second region comprising the extruded polymer filaments having a second density less than the first density.

2. The article according to claim 1, wherein The first region and the second region define at least one boundary between the first region and the second region, the at least one boundary extending at least partially across the body.

3. The article according to claim 2, wherein The at least one boundary between the first region and the second region is curved.

4. The article according to claim 2, wherein: The at least one boundary between the first region and the second region extends at an angle less than perpendicular to the longitudinal direction.

5. The article according to claim 1, wherein The first region and the second region define at least one boundary between the first region and the second region, the at least one boundary extending completely across the body.

6. The article according to claim 1, wherein The body includes a plurality of intermediate preforms, wherein each of the intermediate preforms is adapted to be separated and molded into a seat pad.

7. A seat assembly comprising: Seat frame; Seat covers; as well as A body, the body comprising a plurality of extruded polymer filaments, the plurality of extruded polymer filaments being randomly oriented and bonded together to form an intermediate preform, the intermediate preform comprising a first region of the extruded polymer filaments and a second region of the extruded polymer filaments, the first region of the extruded polymer filaments having a first density, the second region of the extruded polymer filaments having a second density less than the first density, wherein the intermediate preform is molded to form a molded seat pad.

8. The seat assembly of claim 7, wherein: The first region and the second region define at least one boundary between the first region and the second region, the at least one boundary extending at least partially across the body.

9. The seat assembly of claim 7, wherein: The first region and the second region define at least one boundary between the first region and the second region, the at least one boundary extending completely across the body.

10. The seat assembly of claim 9, wherein: The at least one boundary between the first region and the second region is curved.

11. A method comprising: melting a polymer resin to form a molten polymer; extruding the molten polymer through a die to form extruded polymer filaments; shaping and combining the extruded polymer filaments to form a filament strip comprising a predetermined cross-section; pulling the filament strip into the cooling bath along the longitudinal direction with a plurality of puller belts arranged transverse to the longitudinal direction, wherein each of the puller belts moves one of a plurality of portions of the filament strip along the longitudinal direction; as well as The plurality of tractor belts are controlled to move one of the plurality of portions of the filament ribbon at a different speed relative to other tractor belts of the plurality of tractor belts to control density of the plurality of portions of the filament ribbon zoned across a width of the polymer filament ribbon.

12. The method according to claim 11, further comprising: The filament strip is cut transversely to the longitudinal direction to form a plurality of seat pad preforms.

13. The method according to claim 12, further comprising: The plurality of seat pad preforms are molded into contour shapes of a plurality of seat pads.

14. The method according to claim 13, further comprising: The plurality of seat cushions are each assembled to one of the plurality of seat frames.

15. The method according to claim 13, further comprising: Each of the plurality of seat pads is covered with one of a plurality of seat covers.

16. The method according to claim 11, wherein: The polymer resin is HDPE.

17. The method according to claim 11, wherein: The polymer resin is a thermoplastic polymer.

18. The method according to claim 11, wherein: The polymer resin is LLDPE.

19. A polymer filament ribbon produced according to the method of claim 11.

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