Improved tufted carpet system for automobile floor

Abstract

A tufted carpet system for molding an automotive trim component or floor includes a non-woven primary backing, a plurality of tufts comprising bulked continuous filament (BCF) yarns inserted into the primary backing and protruding on opposite sides of the insertion to form tufted tufts, a second backing layer, and an adhesive, the adhesive is located between and in contact with a surface of the main backing opposite the pile and the second backing.

Description

Technical Field

[0001] The present invention relates to a carpet system and a carpet floor structure for a motor vehicle (such as an engine-driven motor vehicle, a hybrid motor vehicle or a battery electric vehicle). Background Art

[0002] The floor in a motor vehicle is covered by a multi-layer carpet structure, which has an aesthetically pleasing surface formed by the carpet. The carpet itself is also a multi-layer system. A tufted carpet system can include a primary backing fabric, and a plurality of tufted pile clusters containing bulked continuous filament (BCF) yarns. The BCF yarns, which contain multiple filaments, are inserted through the primary backing fabric by tufting at a predetermined gauge and cut to a certain length to form the tufted pile clusters. The tufting is inserted into the back side of the primary backing and protrudes on the opposite side of the insertion point to form the pile. The filaments within the tufting as well as the tufting in the primary backing need to be bonded. Over the years, different techniques have been developed to achieve good filament locking or bonding within the tufting yarns, as well as good tufting locking or bonding of the tufting yarns in the primary backing layer.

[0003] Wear tests on the carpet surface show the effect of wear on filament locking - by showing weight loss in the form of fiber loss after a certain number of cycles using an abrasive disc, and the effect on the filaments within the tufting yarns. If the tufting locking is low or fails, open areas will appear in the tufting, and the primary backing layer will become visible in a checkerboard pattern. If the filament locking fails, high fiber loss can be observed, also resulting in a visible appearance of the primary backing layer through the pile. Typically, the wear test is carried out until a certain number of cycles are reached or the backing becomes visible. Thus, if the backing becomes visible at the beginning of the test, the product fails.

[0004] To achieve good durability of the carpet surface, good wear resistance needs to be achieved. Many optimizations done in the past have been dedicated to optimizing the BCF yarns, or increasing the bonding strength of the adhesive systems used. For example, in the past, a combination of a primary backing layer, an adhesive layer and a second backing layer covering the back side of the tufting has been used to enhance the bonding of the tufting. An attempt has been made to use a primary backing layer including an adhesive to further enhance tufting bonding and filament locking.

[0005] For example, US5532035 discloses a carpet structure based on polyethylene terephthalate (PET), which has a PET primary backing layer and a second backing layer as well as PET tufted pile. The primary backing layer includes additional low melting point PET fibers, which melt when the carpet structure is heated and bond the tufting within the primary backing when cooled again, locking the tufting in place. Although this can achieve tufting locking, it lacks strong filament bonding or locking.

[0006] There is still a gap between the currently used tufting and filament bonding systems and the wear resistance performance desired by customers.

[0007] The use of newer fiber materials and the search for floor structures based on a single material (including any adhesives) further require new solutions. Using one type of polymer for all layers and features poses a challenge because there is a high risk of degrading one layer while bonding other layers during different heat steps. The surface material is degraded, in particular, by softening the filaments and thus flattening or losing the elasticity of the tufts, or by exuding the backing material to the surface and soiling the pile.

[0008] Another problem with current carpet structures is the flexural stiffness of the carpet system that is part of the carpet structure, because there is a trend towards lighter carpet structures, defined as the flexural stiffness of the carpet structure from the pile layer to the second backing layer, which becomes more important for achieving a globally rigid surface underfoot.

[0009] In addition, the placement of electronic components under the carpet structure requires a robust and waterproof system.

[0010] The object of the present invention is to provide an alternative tufted carpet system for molding automotive trim parts or floors, which has enhanced wear resistance compared to existing solutions. In addition, the carpet system and the floor structure can fully meet all the necessary requirements for placement in a vehicle. Furthermore, a method for producing such a carpet system is provided. Summary of the Invention

[0011] This object is achieved by a tufted carpet system for molding automotive trim parts or floors, the tufted carpet system comprising a non-woven main backing, a plurality of tufts comprising bulk continuous filament (BCF) yarns, a second backing layer, and an adhesive, wherein the BCF yarns are inserted into the main backing and protrude on the opposite side of the insertion point to form tuft piles, and the adhesive is located between and in contact with the surface of the main backing opposite the piles and the second backing, as claimed.

[0012] By combining BCF yarn filaments 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 not more than 150 PA.s at 220 °C, it is ensured that at least the tufts and filaments of the BCF yarns are locked into the main backing of the final trim part.

[0013] Surprisingly, reducing the modification ratio of the trilobal filaments of the BCF yarn to below 1.8, in combination with an adhesive having different melt viscosities with temperature, results in a good first distribution during the adhesive application stage, while the higher melt viscosity during the second molding stage prevents excessive redistribution in the yarn bundle. An optimal final distribution and a balance between filament locking and tuft locking are produced. It has been found that through the combination of temperature and viscosity, an increase in wear resistance is measurable, accompanied by an increase in the final cycle - meaning more wear cycles can be carried out before the backing becomes visible through the pile, and less fiber loss is measured. Even more surprisingly, this is not the case for all roller product materials tested before molding. Only after the molding step does the increase in wear resistance become apparent.

[0014] Preferably, the adhesive is a thermoplastic-based adhesive. The adhesive may include at least one polyester polymer or copolymer, preferably a terephthalate-based polyester, preferably at least one of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polypropylene terephthalate (PTT) or any combination thereof. Preferably, the adhesive does not contain fillers or contains a small amount of inert fillers. The inert filler can be one of a mineral or a polymer as an inactive filler component, for example in the form of fiber fragments, as part of the recycled material mixed into the adhesive before application. The adhesive may also have an active component based on recycled components. For example, recycled or recycled polyester from automotive or post-consumer waste.

[0015] The density of the adhesive is preferably 0.9 to 1.2 kg / dm3. The areal weight of the adhesive applied to the back of the tuft main backing layer can be 100 to 500 g / m2.

[0016] The adhesive used is preferably a heat-activated adhesive, a coated adhesive or an extruded adhesive, which contains a polymer or copolymer based on a terephthalate-based polyester, preferably a copolyester having at least one terephthalate-based polyester, such as polybutylene terephthalate PBT or polyethylene terephthalate PET or a combination of two or more polyesters or copolyesters.

[0017] BCF yarns are known in the industry and are made from multifilaments that form bulked yarns through air texturing and entanglement. The standard production process of BCF yarns can include the following steps: melt spinning multiple continuous filaments; extruding multiple continuous filaments; quenching the extruded filaments; stretching the quenched filaments; deforming the stretched filaments.

[0018] The BCF yarns used can be held together, for example, by air entanglement. During the tufting process, appropriate entanglement increases process stability and the opening of the tufted yarns in the main backing layer.

[0019] The BCF yarn according to the present invention is spun through a trilobal spinneret exit to form a trilobal structure with a predetermined modification ratio, although this may vary slightly in different stretching and cooling steps after the spinning step. Preferably, the BCF yarn comprises polyester-based filaments, preferably terephthalate-based polyesters, preferably at least one of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polytrimethylene terephthalate (PTT), or any combination thereof. The combination of the modification ratio of these polyesters with the filaments and the melt viscosity-temperature range of the adhesive further enhances the wear resistance of the molded carpet system while maintaining good resilience of the carpet pile during use.

[0020] Preferably, the BCF yarn is made of recycled PET and / or PBT. Preferably, the intrinsic viscosity is from 0.4 to 1.3, more preferably from 0.4 to 1.0.

[0021] The BCF yarn can contain from 40 to 300 filaments, preferably from 60 to 210 filaments. The yarn can be tufted to any conventional gauge for automotive applications, preferably using a gauge of 1 / 18, 1 / 10, 5 / 64, or 1 / 16. The gauge refers to the number of surface pile yarns in one inch measured along the width of the tufted carpet. It is determined by the spacing and number of needles per inch on the tufting machine and is expressed as a fraction.

[0022] In order to enable the main backing to be stretched in all directions during the molding process, a nonwoven main backing layer is used. This can be a spunbond nonwoven. The spunbond nonwoven is preferably made of continuous bicomponent filaments that are laid and thermally bonded to form a web.

[0023] The spunbond nonwoven can optionally contain a mixture of continuous monocomponent filaments and continuous bicomponent filaments.

[0024] Alternatively, the main backing can comprise thermoplastic staple fibers and a thermoplastic binder.

[0025] Preferably, the main backing layer further comprises a polymer or copolymer of terephthalate-based polyester.

[0026] The second 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 second backing layer. It can be applied directly to the adhesive during the backcoating stage, or it can be applied during the second heating and molding step. The choice of the second backing layer material depends on the use of any additional layers and requirements. While a film layer or a foil layer can make the final automotive component waterproof, using a thicker felt layer can increase the overall perceived stiffness of the pile layer when a force is applied to the pile surface. This may be important in areas where passengers enter the vehicle and apply a force to the pile surface.

[0027] The tufted carpet system according to the present invention may further comprise at least one or more additional layers, preferably one of a foam layer, a felt layer, a film layer, a thermoplastic layer or a highly filled thermoplastic elastomer layer adjacent to the second backing layer.

[0028] The tufted carpet system according to one of the preceding claims, characterized in that the BCF yarn comprises from 40 to 300 filaments, preferably from 60 to 210 filaments.

[0029] The tufted carpet system according to one of the preceding claims, characterized in that the diameter of the filaments is preferably in the range of from 1 to 20 decitex, preferably from 6 to 18 decitex, per filament.

[0030] Wear can be tested according to DIN53754 (German Industrial Standard). After the test equipment of Taber Industries, the weight loss does indicate the abrasion resistance or Taber wear. This procedure is a method for determining the abrasion resistance of decorative materials by a rotating platform sample holder and a double grinding wheel type machine. The wheels press on the pile layer of the sample while the sample rotates. After the sample has rotated a certain number of times, the loss of its fiber weight is measured and the visual appearance is evaluated. In particular, the chessboard-like appearance after the wear test indicates a defect in tuft locking, while a high weight loss indicates poor filament locking.

[0031] The melt viscosity μ of the adhesive is measured according to ASTM D1238 (equivalent to ISO 1133). The measurement can be carried out, for example, on a rheometer.

[0032] The fibers, filaments and / or yarns used may be based on bio-based, recycled or recyclable materials, or may include source materials of such types.

[0033] The molecular weight of the BCF yarn can be measured using different measurement methods known in the industry, such as using gel permeation chromatography (GPC).

[0034] The method for producing a molded tufted carpet system according to one of the preceding claims, which at least has the following steps:

[0035] a. Tufting a BCF yarn having trilobal filaments with a modification ratio of 1.5 to 1.8 into a non-woven primary backing;

[0036] b. Applying an adhesive on the surface opposite to the pile at a temperature of 180 to 220 °C, wherein the viscosity of the adhesive at 220 °C is not more than 150 PA·s, and rapidly cooling the so-applied adhesive;

[0037] c. Heat the surface containing the adhesive and the second backing layer, stack the two materials in a mold with the adhesive layer facing the second backing layer, and mold the final part, where the adhesive has a melt viscosity of at least 100 Pa·s at 150 °C, such that the adhesive redistributes in the tufts and filaments and in the main backing, thereby achieving tuft locking and filament locking.

[0038] Preferably, the adhesive is applied by coating, preferably by roll coating or spraying.

[0039] The method is further optimized when the adhesive comprises a polymer or copolymer based on terephthalic acid-based polyester (preferably polyethylene terephthalate PET or polybutylene terephthalate PBT or a mixture of terephthalate-based polyesters (including at least one of PET or PBT)).

[0040] Use of a tufted carpet system according to one of the preceding claims in molding a decorative part, preferably for an interior dashboard part, a floor part, a floor mat, a trunk cladding part, a door trim part, a front storage cladding part, or a side panel trim part.

[0041] Preferably, the produced carpet system or an automotive part comprising the carpet system contains at least 95%, preferably 99%, of a polyester-based component, such that the entire part can be recycled mechanically and / or thermally and / or chemically during the polyester recycling process.

[0042] Figure 1 Shown is a tufted carpet system 1 according to the present invention, which has a nonwoven main backing 3, and the nonwoven main backing 3 has a plurality of tufts 8 comprising bulk continuous filament (BCF) yarns 6. The BCF yarns are inserted into the main backing and protrude on the opposite side of the insertion point to form the pile 8. On the back of the main backing, the yarns inserted in this way form loops 7. The plurality of tufts together form the carpet pile 2. The pile surface 2 faces the passenger compartment and passengers may come into contact with it, so the carpet surface should be aesthetically pleasing, free of defects or streaks, and have a good level of abrasion resistance and elasticity.

[0043] Good abrasion resistance depends on filament locking and tuft locking. Filament locking is defined as the pulling out of the filaments 6 from the bundle forming the tuft 8. Tuft locking is the pulling out of the entire tuft at once. Both rely on the adhesive 4 used on the back of the main backing.

[0044] However, a tufted carpet system used on a carpet floor part or a decorative part of a motor vehicle is molded into a desired three-dimensional shape, where the adhesive is heated and redistributed again while the main backing and all other layers are stretched and shaped. The perfect result of the flat roller material may ultimately be destroyed by the molding step.

[0045] Surprisingly, it has been found that the combination of the modification ratio of the BCF yarn and the melt viscosity of the optimized adhesive within a certain temperature range enables the first application and redistribution such that tuft locking and filament locking are in a preferred balance. This results in an overall increase in wear performance without tuft pull-out, an increased end cycle of the wear test, and reduced fiber loss.

[0046] The adhesive according to the invention can be applied to the back side of the tufted primary backing and covered with a second backing layer. This can be a non-woven layer, a film layer, or a felt layer. For example, a felt layer comprising polyester-based staple fibers can be used, preferably a carded, cross-laid, and needled felt and / or an air-laid felt with or without needling. The felt layer can comprise an adhesive, preferably polypropylene PP or a polyester-based adhesive, for example in the form of binder fibers or combined as bicomponent binder fibers, where one component has a lower melting temperature and melts and bonds the surrounding fibers during the molding of the part. Preferably, the felt layer is based only on polyester fibers and is ultimately combined with bicomponent core-sheath binder fibers, where the sheath is a low-melting polyester forming the bonding component.

[0047] The choice of the second layer can depend on the additional layer (not shown) used under the carpet system. The additional layer used can be at least one of a foam layer, a felt layer, a thermoplastic layer (such as a film layer or a filled thermoplastic elastomer layer) or a combination of these layers.

[0048] For example, the carpet system can be placed on top of or laminated to an isolation mass-spring system, which has a mass layer (also known as a heavy layer) typically formed from an extruded blank of a highly filled thermoplastic material and a soft decoupling layer made of foam or felt material.

[0049] An example of a carpet system according to the invention is a tufted recycled PET-based filament 1200 / 144 dtex BCF yarn into a polyester spunbond primary backing layer with an areal weight of 120 gsm. A polyester-based adhesive is applied to the back side of the tufted primary backing, and a second backing layer is placed and bonded to the adhesive. As the second backing, a 450 gsm fiber layer is used, such as a shoddy cotton material, preferably needled, having at least 70% recycled fibers and up to 30% adhesive, such as bicomponent fibers. Shoddy material is generally a mixture of fibers, where shoddy is defined by the main material of the shoddy material, so a cotton shoddy material has more than 50% cotton material but can include other fibers, such as preferably polyester-based materials.

[0050] Alternatively, the shoddy material can be a shoddy polyester felt, preferably needled, based on polyester containing waste fragments, textiles, and a polyester adhesive. Preferably, a 100% polyester-based shoddy material is used.

[0051] Figure 2Shows a cross-section of a preferred trilobal filament 6 that forms the basis of a BCF yarn. As shown, the modification ratio is the ratio between the outer circle X and the inner circle Y.

[0052] A high modification ratio will indicate a trilobal structure with long and thin arms, while a low modification ratio will indicate a trilobal structure evolving towards a triangular direction. The shape of the BCF yarn has been optimized in the past according to the appearance and elasticity of the carpet pile. Surprisingly, the modification ratio also has a direct impact on the distribution and even more importantly the redistribution of the adhesive used to obtain tuft locking and filament locking.

[0053] It is known that the modification ratio of the filament optimizes the visual appearance of the tufts in the final carpet, as reflected in the gloss and elasticity of the tufts above the bonding area. Surprisingly, the modification ratio has an impact on the actual fiber and tuft locking results. Although a higher modification ratio was thought to be preferable, in fact a lower modification ratio below 1.8 performs better in wear tests. At the same melt viscosity, by increasing the modification ratio above 1.8, filament locking increases, but at the expense of tuft locking. It can even be observed that during the wear test, all the tufts are pulled out from the surface at an early stage, while the overall fiber loss is low, resulting in holes appearing on the entire tuft surface. Preferably, a modification ratio of 1.5 to 1.8 is used for BCF filament yarns.

[0054] At lower modification ratios, the balance between filament locking and tuft locking is enhanced. While a decrease in melt viscosity shows an increase in filament locking, at the expense of tuft locking, and an increase in viscosity increases tuft locking but reduces filament locking.

[0055] Surprisingly, a modification ratio below 1.8, and an adhesive with a melt viscosity of at least 100 Pa.s at 150 °C and not more than 150 Pa.s at 220 °C, will show the best balance between tuft locking and filament locking, while maintaining a good surface appearance even after the final component is thermoformed.

[0056] 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), polypropylene terephthalate (PTT) or a combination of terephthalate-based polyesters), this effect can be further improved.

[0057] The carpet system thus formed can be placed on top or laminated to an isolation mass-spring system that has a mass layer (also known as a heavy layer) (7) usually formed from an extruded blank of a highly filled thermoplastic material and a soft decoupling layer (8) made from a foam or felt material.

Claims

1. A tufted carpet system for molding automotive trim parts or floors, comprising a nonwoven primary backing, a plurality of tufts comprising bulked continuous filament (BCF) yarns, a second backing layer, and an adhesive, wherein the BCF yarns are inserted into the primary backing and protrude on the opposite side of the insertion point to form tuft pile, and the adhesive is located between and in contact with the surface of the primary backing opposite the pile and the second backing. It is characterized in that The filaments of the BCF yarns have a trilobal cross-section with a modification ratio of 1.5 to 1.8, and wherein the melt viscosity μ of the adhesive is at least 100 PA.s at 150 °C and less than 150 PA.s at 220 °C, such that it locks at least the tufts and filaments of the BCF yarns in the primary backing.

2. The tufted carpet system according to one of the preceding claims, characterized in that, The density of the adhesive is 0.9 to 1.2 kg / dm 3 .

3. The tufted carpet system according to one of the preceding claims, characterized in that, The adhesive has an areal weight of 100 to 500 g / m².

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

5. The tufted carpet system according to one of the preceding claims, 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 second backing layer.

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

7. The tufted carpet according to one of the preceding claims, wherein the filaments of the BCF yarns comprise recycled polyethylene terephthalate with a molecular weight < 50,000 g / mol, the BCF yarns have a modification ratio of 1.65 to 1.78 and an IV of 0.4 to 0.

9.

8. The tufted carpet system according to one of the preceding claims, wherein the primary backing comprises continuous filaments and an adhesive component, preferably at least one of continuous bicomponent filaments or staple fibers, wherein at least one component with a lower melting temperature is used as an adhesive.

9. The tufted carpet system according to one of the preceding claims, wherein the second backing layer is a foam layer, a felt layer, a film layer, a thermoplastic layer or a highly filled thermoplastic elastomer layer.

10. The tufted carpet system according to one of the preceding claims, characterized in that, The BCF yarns comprise 40 to 300 filaments, preferably 60 to 180 filaments.

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

12. A method for producing a molded tufted carpet system according to one of the preceding claims, having at least the following steps: 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 the adhesive on the surface opposite the pile at a temperature of 180 to 220 °C and rapidly cooling the so-applied adhesive, wherein the viscosity of the adhesive at 220 °C is not more than 150 PA.s; c. Heat the surface with the adhesive and the second backing layer, stack the two materials in a mold with the adhesive layer facing the second backing layer, and mold the final part, wherein the melt viscosity of the adhesive at 150 °C is at least 100 Pa·s, such that the adhesive redistributes among the tufts and filaments and the main backing, thereby achieving tuft locking and filament locking.

13. The method according to claim 12, wherein the adhesive is applied by coating, preferably by roll coating or spraying.

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

15. Use of a tufted carpet system according to one of the preceding claims in a molded decorative part, preferably for an interior dashboard part, a floor part, a floor mat, a trunk lining part, a door trim part, a front storage lining part or a side panel trim part.

Images