Improved tufted carpet system for automotive flooring

Abstract

A molded tufted carpet system for automotive trim components or flooring includes a nonwoven primary backing, a plurality of tufts comprised of bulk continuous filament (BCF) yarns inserted into the primary backing and projecting opposite the insertion to form a tuft pile, a secondary backing layer, and an adhesive between and in contact with the primary and secondary backings on the surface opposite the pile.

Description

[Technical Field]

[0001] The present invention is directed to carpet systems and carpet floor constructions for use in motor vehicles, such as engine driven, hybrid or battery electric vehicles. [Background technology]

[0002] Vehicle interior floors are covered with multi-layer carpet structures, with the carpet providing an aesthetic surface. The carpet itself is a multi-layer system. A tufted carpet system may include a primary backing fabric and multiple pile tufts composed of bulk continuous filament (BCF) yarns. According to this, multiple filament BCF yarns are inserted by tufting through the primary backing fabric at a predetermined gauge and then cut to length to form pile tufts. The tufts are inserted into the back surface of the primary backing and emerge on the opposite side of the insertion surface to form pile. Both the filaments within the tufts and the tufts within the primary backing require bonding. Over the years, different techniques have been developed to achieve good filament bonding or bonding within the tufted yarns and good tuft bonding or bonding of the tufted yarns within the primary backing layer.

[0003] Abrasion testing of carpet surfaces indicates both the effect of abrasion on filament anchorage by showing weight loss in the form of fiber loss after a certain number of cycles with an abrasive disk, and the effect on the filaments within the tufted yarn. If tuft anchorage is low or has failed, open areas will appear within the tufts and the primary backing layer will be visible in the checkerboard pattern. Failure of filament anchorage will result in significant fiber loss, as well as the appearance of the primary backing layer being visible through the pile. Typically, abrasion testing is performed until a certain number of cycles are achieved or the backing is visible. Therefore, if the backing is visible early in the test, the product will be rejected.

[0004] To achieve excellent durability of the carpet surface, it is necessary to achieve excellent wear performance. Therefore, many optimizations in the past have been aimed at optimizing the BCF yarn or increasing the bond strength of the adhesive system used. For example, in the past, a combination of a primary backing layer, a sizing layer, and a secondary backing layer covering the backside of the tufts has been used to increase tuft bond. To further increase tuft bond and filament fixation, attempts have been made to use a primary backing layer containing a binder.

[0005] For example, U.S. Patent No. 5,532,035 discloses a polyethylene terephthalate (PET)-based carpet structure with PET primary and secondary backing layers and PET tufted pile. The primary backing layer contains additional low-melt PET fibers that melt when the carpet structure is heated and bind the tufts within the primary backing when cooled again, securing the tufts in place. While this may allow for tuft retention, it lacks strong filament bonding or fixation.

[0006] There is still a gap between the current tuft and filament bonding systems in use and the wear performance desired by customers.

[0007] The use of more novel materials for the fibers and the quest to have flooring structures based on a single material, including any adhesive, calls for more novel solutions. The use of one type of polymer for all layers and features poses many challenges due to the high risk of degrading one layer while bonding the other during different thermal processes, particularly degrading the face material by either softening the filaments and therefore the tufts, causing them to flatten and / or lose their elasticity, or the backing material bleeding to the surface and staining the pile.

[0008] Another problem with current carpet construction is the bending stiffness of the carpet system as part of the carpet structure. With the trend towards lighter weight carpet construction, the bending stiffness of the carpet structure, defined as the pile layer up to the secondary backing layer, is becoming more important to ensure overall stiffness of the surface when walked on.

[0009] Additionally, the increasing number of electrical components installed underneath carpet structures requires a robust, waterproof system. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] U.S. Patent No. 5,532,035 Summary of the Invention [Problem to be solved by the invention]

[0011] It is an object of the present invention to provide an alternative molded tufted carpet system that has increased wear performance compared to current solutions. Furthermore, the carpet system and flooring structure can meet all the requirements necessary for installation in a vehicle. A method for producing such a carpet system is also provided. [Means for solving the problem]

[0012] The object, as claimed, is to a nonwoven primary backing; a plurality of tufts comprised of bulk continuous filament (BCF) yarns inserted into a primary backing and projecting opposite the insertion to form a tuft pile; a secondary backing layer; and an adhesive between and in contact with the primary backing and the secondary backing on the opposite surfaces of the pile; The present invention is obtained by a molded tufted carpet system for automotive trim parts or flooring, including

[0013] The filaments and tufts of the BCF yarn in at least the primary backing are secured in the final trim component by combining filaments of the BCF yarn having a trilobal cross section with a modification ratio of 1.5 to 1.8 with an adhesive having a melt viscosity μ of at least 100 Pa·s at 150°C and less than 150 Pa·s at 220°C.

[0014] Surprisingly, reducing the trilobal filament modification ratio of the BCF yarn to less than 1.8, combined with an adhesive whose melt viscosity varies with temperature, results in excellent initial distribution during the adhesive application stage, while the higher melt viscosity during the second forming stage prevents excessively high redistribution within the yarn bundle, creating optimal final distribution and a balance between filament fixation and tuft fixation. It was discovered that the temperature and viscosity combination resulted in a measurable increase in abrasion performance with increasing final cycles, meaning that more abrasion cycles were possible before the backing was visible through the pile, with less measured fiber loss. Even more surprisingly, this was not the case for all roll-stock materials tested prior to forming. The increase in abrasion performance was only apparent after the forming process.

[0015] Preferably, the adhesive is a thermoplastic adhesive. The adhesive comprises at least a polymer or copolymer of polyester, preferably a terephthalate-based polyester, preferably polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), or any combination thereof. Preferably, the adhesive contains no or only a small amount of inert filler. The inert filler could be one of minerals or polymers acting as an inert filler component, for example, in the form of fiber fragments as part of recycled materials mixed into the adhesive before application. The adhesive could also have an active ingredient based on recycled content, for example, recycled or regenerated polyester derived from automotive waste or post-consumer waste.

[0016] Preferably, the adhesive has a strength of 0.9 to 1.2 kg / dm 3 The adhesive applied to the backside of the tufted primary backing layer has a density of m 2 They have an area weight of 100 to 500 grams per piece.

[0017] The adhesive used is preferably a heat-activated, coating or extrusion adhesive comprising a polymer or copolymer based on a terephthalate polyester, preferably a copolyester with at least one terephthalate polyester, such as polybutylene terephthalate PBT or polyethylene terephthalate PET, or a combination of two or more polyesters or copolyesters.

[0018] BCF yarns are known in the industry and are produced from multifilaments that are textured and entangled with an air stream to form an expanded yarn. A standard production process for BCF yarns may include the steps of melt spinning multiple continuous filaments, extruding multiple continuous filaments, quenching the extruded filaments, drawing the quenched filaments, and texturing the drawn filaments.

[0019] The BCF yarns used may be entangled, for example by air flow, to prevent the filaments from dispersing. Proper entanglement increases the openness and process stability of the tufted yarns in the primary backing layer during the tufting process.

[0020] The BCF yarns of the present invention are spun through a trilobal spinneret outlet to form a trilobal structure with a predetermined modification ratio, which may be slightly altered by different post-spinning drawing and cooling steps. Preferably, the BCF yarns are characterized by comprising polyester-based filaments, preferably terephthalate-based polyesters, preferably polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), or any combination thereof. The combination of these polyesters with the filament modification ratio and adhesive melt viscosity-temperature range further enhances the wear performance of the resulting carpet system while maintaining excellent carpet pile resilience during use.

[0021] Preferably, the BCF yarn is produced using recycled PET and / or PBT, preferably having an intrinsic viscosity of 0.4 to 1.3, more preferably 0.4 to 1.0.

[0022] BCF yarns may contain 40 to 300 filaments, preferably 60 to 210 filaments. The yarns are tufted to any standard gauge used in automotive applications, preferably 1 / 18, 1 / 10, 5 / 64, or 1 / 16 gauge. Gauge refers to the number of surface pile yarns within an inch measured across the width of the tufted carpet. It is determined by the needle spacing and number per inch on the tufting machine and is expressed as a percentage.

[0023] A nonwoven primary backing layer is used to allow stretch of the primary backing during molding in all directions. This may be a spunbond nonwoven. Spunbond nonwovens are preferably made of continuous bicomponent filaments that are laid down and thermally bonded to form a web.

[0024] Spunbond nonwovens may alternatively comprise a mixture of continuous monocomponent and continuous bicomponent filaments.

[0025] Alternatively, the primary backing may include thermoplastic staple fibers and a thermoplastic binder.

[0026] Preferably, the primary backing layer is also comprised of a terephthalate-based polyester polymer or copolymer.

[0027] The secondary backing layer can be one of a foam layer, a felt layer, a film layer, a thermoplastic layer, or a highly filled thermoplastic elastomer layer adjacent to the secondary backing layer. It can be applied directly to the adhesive during the backcoating step or during a second heating and molding process. The choice of secondary backing layer material depends on the use and requirements of any additional layers, while a film or foil layer can make the final automotive part waterproof, and a thicker felt layer can increase the overall stiffness of the pile layer as perceived when a force is applied to the pile surface. This can be important in areas where occupants enter the vehicle and apply force to the pile surface.

[0028] The tufted carpet system of the present invention may further comprise at least one additional layer adjacent to the secondary backing layer, preferably the secondary backing layer being one of a foam layer, a felt layer, a film layer, a thermoplastic layer, or a highly filled thermoplastic elastomer layer.

[0029] A tufted carpet system according to any one of the preceding claims, characterized in that the BCF yarn contains between 40 and 300 filaments, preferably between 60 and 210 filaments.

[0030] A tufted carpet system according to any one of the preceding claims, characterized in that the filament diameter is preferably in the range of 1 to 20 decitex per filament, preferably 6 to 18 decitex.

[0031] Abrasion can be tested according to DIN 53754 (German Industrial Standard). Weight loss is a positive indicator of abrasion resistance, or Taber abrasion, according to a Taber Industries testing device. This procedure is a method for determining the abrasion resistance of trim materials using a rotary platform sample support and a dual abrasion wheel type machine. The wheel is pressed onto the pile layer of the sample while the sample rotates. After the sample has been rotated a certain number of times, its fiber weight loss is measured and the visual appearance is assessed. In particular, a checkered appearance after the abrasion test indicates tuft fixation defects, while a high weight loss indicates poor filament fixation.

[0032] The melt viscosity μ of the adhesive is measured according to ASTM D1238 (equivalent to ISO 1133). The measurement may be carried out, for example, with a flowmeter.

[0033] The fibres, filaments and / or yarns used may be based on bio-sourced, recycled or regenerated materials or may contain materials of such types of sources.

[0034] The molecular weight of BCF yarns can be measured by different methods known in the art, for example using gel permeation chromatography (GPC).

[0035] 1. A method of producing a molded tufted carpet system according to any one of the preceding claims, comprising at least: a. tufting a BCF yarn with trilobal filaments having a modification ratio of 1.5 to 1.8 into a nonwoven primary backing; b. applying an adhesive having a viscosity of 150 Pa·s or less at 220°C to the opposite surface of the pile at a temperature of 180-220°C, and then rapidly cooling the adhesive thus applied; c. Heating the adhesive-containing surface and the secondary backing layer, laminating both materials in a mold with the adhesive layer facing the secondary backing layer, and molding the final part, wherein the adhesive has a melt viscosity of at least 100 Pa.s at 150°C, thereby allowing the adhesive to redistribute within the tufts and filaments and primary backing to secure the tufts and filaments.

[0036] Preferably, the application of the adhesive is carried out by coating, preferably by roller coating or spray coating.

[0037] The method is further optimized when the adhesive comprises a polymer or copolymer based on a terephthalate-based polyester, preferably polyethylene terephthalate PET or polybutylene terephthalate PBT or a mixture of terephthalate-based polyesters with at least one of PET or PBT.

[0038] 10. Use of a tufted carpet system according to any one of the preceding claims in moulded trim components, preferably interior dashboard components, flooring components, floor mats, trunk cladding components, door trim components, front storage cladding components and side panel trim components.

[0039] Preferably, the carpet system or automotive part containing the produced carpet system comprises at least 95%, preferably 99%, polyester-based components, thus allowing the entire part to be reclaimed either mechanically and / or thermally and / or chemically in a polyester reclaiming process. DETAILED DESCRIPTION OF THE INVENTION

[0040] Figure 1 shows a tufted carpet system according to the present invention with a nonwoven primary backing 3 having a plurality of tufts 8 made up of bulk continuous filament (BCF) yarns 6. The BCF yarns are inserted into the primary backing and protrude on the opposite side of the insertion to form tufts 8. On the back surface of the primary backing, the inserted yarns form loops 7. The multiple tufts together form the carpet pile 2. The pile surface 2 faces the passenger compartment and may be in contact with the passengers, so the carpet surface must be free of defects and marks, be aesthetically pleasing, and have excellent levels of wear resistance and resilience.

[0041] Good abrasion resistance depends on filament settling and tuft settling. Filament settling is defined as the pull-out of filaments 6 from the bundle to form tufts 8. Tuft settling is the instantaneous pull-out of the entire tuft. Both depend on the adhesive 4 used on the backside of the primary backing.

[0042] However, because tufted carpet systems used on carpet flooring or trim components within automotive vehicles are molded into the required three-dimensional shape, the adhesive is reheated and redistributed while the primary backing and all other layers are stretched and molded. It is believed that the molding process can potentially destroy the perfect results in flat roll material.

[0043] It has been unexpectedly discovered that optimizing the combination of adhesive melt viscosity and BCF yarn modification rate over a temperature range allows for a favorable equilibrium redistribution of initial application and tuft and filament anchorage, resulting in overall increased wear performance without tuft pullout, reduced end cycles and fiber loss in wear tests.

[0044] The adhesive of the present invention may be applied to the back of the tufted primary backing and covered with a secondary backing layer, which may be a nonwoven layer, a film, or a felt layer. For example, a felt layer containing polyester-based staple fibers, preferably an air-laid felt with or without carding, cross-lapping, and needle-driving and / or needling, may be used. The felt layer may contain a binder, preferably a polypropylene (PP) or polyester-based binder, in the form of binder fibers or combined as a bicomponent binder fiber, where one component has a relatively low melting temperature and binds the surrounding fibers during part molding. Preferably, the felt layer is based solely on polyester fibers, which are ultimately combined with a bicomponent core-sheath binder fiber, where the sheath is a low-melting polyester that forms the bonding component.

[0045] The choice of secondary layer may depend on the additional layers used underneath the carpet system (not shown), which may be foam layers, felt layers, thermoplastic layers such as films or filled thermoplastic elastomer layers, or combinations of such layers.

[0046] For example, a carpet system could be placed on top of or laminated to an isolation mass-spring system with a mass layer (also called a weight layer) typically formed from an extruded blank of highly filled thermoplastic material and a soft decoupling layer made of either foam or felt material.

[0047] One example of a carpet system according to the present invention is a 1200 / 144 dtex BCF recycled PET filament yarn tufted into a 120 gsm areal weight polyester spunbond primary backing layer. A polyester adhesive is coated onto the back of the tufted primary backing, and a secondary backing layer is applied and bonded to the adhesive. The secondary backing is a 450 gsm fibrous layer, preferably a needled shoddy cotton material, with at least 70% recycled fiber and up to 30% binder, such as a bicomponent binder. Shoddy materials are typically blends of fibers, with shoddy defined by the bulk material of the shoddy material. Thus, cotton shoddy has more than 50% cotton material, but may contain other fibers, such as polyester-based materials.

[0048] Alternatively, the shoddy material may be a polyester-based, preferably needled, shoddy polyester felt containing polyester-containing waste chips, fabric, and a polyester binder. Preferably, a 100% polyester-based shoddy material is used.

[0049] Figure 2 shows the cross section of a preferred trilobal filament 6 that forms the base of a BCF yarn. The modification ratio is the ratio between the outer circle X and the inner circle Y as labeled in the figure.

[0050] It is believed that a high modification rate indicates a trilobal structure with long, thin arms, while a low modification rate indicates a trilobal structure approaching a triangular shape. The shape of BCF yarns has been optimized in the past in relation to carpet pile appearance and resilience. Surprisingly, the modification rate also has a direct effect on the distribution and, more importantly, redistribution of the adhesive used to secure the tufts and filaments.

[0051] The filament modification ratio is known to optimize the visual appearance of the tufts in the final carpet in terms of the gloss and resilience of the tufts above the bonded area. Surprisingly, the modification ratio influences the actual fiber and tuft fixation results. While it is believed that a relatively high modification ratio should be selected, in fact, a relatively low modification ratio below 1.8 shows better performance in abrasion tests. By increasing the modification ratio above 1.8 at the same melt viscosity, filament fixation increased but at the expense of tuft fixation. Furthermore, during abrasion tests, while all tufts were pulled out of the surface already at an early stage, fiber loss was generally low, and even holes were observed within the overall tufted surface. Preferably, a modification ratio of 1.5 to 1.8 is used for BCF filament yarns.

[0052] At lower modification rates, the balance between filament and tuft fixation was enhanced: reducing the melt viscosity showed increased filament fixation but at the expense of tuft fixation, while increasing the viscosity increased tuft fixation but decreased filament fixation.

[0053] Surprisingly, a modification ratio of less than 1.8 and a melt viscosity of at least 100 Pa·s at 150°C and 150 Pa·s or less at 220°C appear to represent an optimal balance between tuft fixation and filament fixation while maintaining excellent surface morphology even after thermoforming of the final part.

[0054] The effect can be further improved by using polyester-based BCF yarns, preferably BCF yarns based on terephthalate-based polyesters, such as BCF yarns made from polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT) or combinations of terephthalate-based polyesters.

[0055] The carpet system thus formed may be placed on top of or laminated to an insulating mass-spring system with a mass layer (also called a weight layer) (7) usually formed from an extruded blank of highly filled thermoplastic material and a soft decoupling layer (8) made of either foam or felt material.

Claims

1. Nonwoven primary backing, a plurality of tufts comprised of bulk continuous filament (BCF) yarns inserted into the primary backing and projecting opposite the insertion to form a tuft pile; a secondary backing layer; and an adhesive between and in contact with the primary backing and the secondary backing on the opposite surface of the pile; 1. A molded tufted carpet system for automotive trim parts or flooring, comprising: the filaments of the BCF yarn have a trilobal cross section with a modification ratio of 1.5 to 1.8, and the adhesive has a melt viscosity μ of at least 100 Pa·s at 150°C and a melt viscosity μ of less than 150 Pa·s at 220°C, thereby securing at least the filaments and the tufts of the BCF yarn within the primary backing. Tufted carpet system.

2. The adhesive has a viscosity of 0.9 to 1.2 kg / dm ３ 10. The tufted carpet system of claim 1, having a density of

3. The area weight of the adhesive is m ２ 3. The tufted carpet system according to claim 1, wherein the weight of the tufted carpet is 100 to 500 grams per tuft.

4. 4. The tufted carpet system according to any one of claims 1 to 3, characterized in that the adhesive comprises at least a polymer or copolymer of polyester, preferably a terephthalate-based polyester, preferably polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), or any combination thereof.

5. The tufted carpet system of any one of claims 1 to 4, further comprising at least one of a foam layer, a felt layer, a film layer, a thermoplastic layer, or a highly filled thermoplastic elastomer layer adjacent to the secondary backing layer.

6. 6. The tufted carpet system of any one of claims 1 to 5, characterized in that the BCF yarns comprise polyester-based filaments, preferably terephthalate-based polyesters, preferably at least one of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), or any combination thereof.

7. 7. The tufted carpet system of claim 1, wherein the filaments of the BCF yarn comprise recycled polyethylene terephthalate having a molecular weight of less than 50,000 g / mol, a modification ratio of 1.65 to 1.78, and an IV of 0.4 to 0.

9.

8. 8. The tufted carpet system of claim 1, wherein the primary backing comprises continuous filaments and a binder component, preferably at least one of staple fibers or continuous bicomponent filaments with at least one component having a relatively low melting temperature to act as a binder.

9. The tufted carpet system of any one of claims 1 to 8, wherein the secondary backing layer is a foam layer, a felt layer, a film layer, a thermoplastic layer, or a highly filled thermoplastic elastomer layer.

10. A tufted carpet system according to any one of claims 1 to 9, characterized in that the BCF yarns contain between 40 and 300 filaments, preferably between 60 and 180 filaments.

11. A tufted carpet system according to any one of claims 1 to 10, characterized in that the diameter of the filaments is preferably in the range of 1 to 20 decitex per filament, preferably 6 to 18 decitex.

12. A method for producing a molded tufted carpet system according to any one of claims 1 to 11, comprising at least: a. tufting a BCF yarn with trilobal filaments having a modification ratio of 1.5 to 1.8 into a nonwoven primary backing; b. applying an adhesive having a viscosity of 150 Pa·s or less at 220°C to the opposite surface of the pile at a temperature of 180-220°C, and rapidly cooling the adhesive so applied; c) heating the adhesive-containing surface and the secondary backing layer, laminating both materials in a mold with the adhesive layer facing the secondary backing layer, and molding the final part, wherein the adhesive has a melt viscosity of at least 100 Pa s at 150°C, thereby redistributing the adhesive within the tufts and filaments and the primary backing to secure the tufts and filaments.

13. 13. The method according to claim 12, wherein the application of the adhesive is carried out by coating, preferably by roller coating or spray coating.

14. 14. The method of claim 12 or 13, wherein the adhesive comprises a polymer or copolymer based on a terephthalate-based polyester, preferably polyethylene terephthalate (PET) or polybutylene terephthalate (PBT) or a mixture of terephthalate-based polyesters with at least one of PET or PBT.

15. Use of the tufted carpet system according to any one of claims 1 to 14 in moulded trim parts, preferably interior dashboard parts, flooring parts, floor mats, trunk cladding parts, door trim parts, front storage cladding parts and side panel trim parts.

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