Ultralight high-wear-resistant tpu / textile composite material for luggage and preparation process thereof

Abstract

This invention discloses a method for preparing an ultralightweight, highly abrasion-resistant TPU / textile composite material for bags and luggage, comprising the following steps: weaving a mesh base fabric using a warp knitting machine; activating and pretreating the surface of a TPU film; coating an adhesive onto the activated surface of the TPU film obtained in the previous step and drying it; hot-pressing the mesh base fabric and the TPU film at multiple points to obtain the TPU / textile composite material; and finishing and shaping the TPU / textile composite material obtained in the previous step. The advantages of this invention include: the prepared composite material possesses multiple advantages such as ultralight weight, high abrasion resistance, softness, strong interface, breathability, and environmental friendliness. It can be widely used in the fabric preparation of various bag and luggage products such as high-end trolley cases, backpacks, outdoor bags, and briefcases, and can also be extended to outdoor products, protective equipment, and other fields, possessing significant industrial application value and market prospects.

Description

Technical Field

[0001] This invention relates to the field of luggage materials technology, and more particularly to luggage material preparation technology. Background Technology

[0002] As the luggage industry rapidly develops towards lightweight, durable, comfortable, and high-end products, the market has placed more stringent demands on the comprehensive performance of luggage fabrics. On the one hand, they need to be ultra-lightweight to reduce the weight of the luggage itself, improve carrying convenience, and meet consumers' needs for lightweight travel. On the other hand, they need to have excellent abrasion resistance to resist friction wear during daily use and extend the service life of the luggage. At the same time, they also need to ensure that the fabric is soft and easy to shape, adapts to different structural designs of luggage, and that the interfaces of the composite materials are firmly bonded, making it less prone to delamination or peeling, thus balancing practicality and aesthetics.

[0003] TPU / textile composites are commonly used in bags and luggage; however, the manufacturing technology for this material still has significant shortcomings, making it difficult to achieve the synergistic balance of the aforementioned multiple properties. Firstly, the weight of a 9000-meter-long nylon filament under standard conditions is its denier (D). Current technologies often use conventional nylon or polyester fabrics with a fineness of 50D or higher as the base fabric, combined with a dense, high-density TPU film, resulting in a high overall areal density of the composite material (typically 150-200). The lightweight design is insufficient (g / m²), failing to meet the lightweight requirements of high-end bags. Secondly, conventional manufacturing processes often employ full-area hot-pressing composite technology, which, while improving interfacial peel strength to some extent, damages the structural integrity of the base fabric and the softness of the material, resulting in stiffened fabric, poor hand feel, and limited improvement in abrasion resistance. The abrasion resistance of existing composite materials' Martindale is mostly between 30,000 and 40,000 revolutions, which is insufficient to meet the abrasion resistance requirements of bags used for long-term, high-frequency applications. Thirdly, some technologies, in pursuit of abrasion resistance, blindly increase the thickness of the TPU film or the density of the base fabric, further sacrificing lightweight and softness, creating a technical bottleneck where "abrasion resistance and lightweight softness cannot be achieved simultaneously." Fourthly, the adhesives used in existing processes are mostly high-solids solvent-based adhesives, which not only increase the weight of the material but also release harmful solvents, failing to meet green production requirements. Furthermore, they have poor compatibility with TPU films and textile base fabrics, easily leading to interfacial delamination problems.

[0004] If a method can be successfully developed to prepare a TPU / textile composite material for bags that is ultra-lightweight, highly wear-resistant, flexible, has a strong interfacial bond, and is environmentally friendly and controllable, this method will have significant industrial application value and market prospects. Summary of the Invention

[0005] The purpose of this invention is to provide an ultra-lightweight, highly wear-resistant TPU / textile composite material for bags and luggage and its preparation process, so as to solve the problem that existing composite materials cannot simultaneously achieve wear resistance and lightness.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A method for preparing an ultralightweight, highly abrasion-resistant TPU / textile composite material for bags and luggage includes the following steps:

[0008] (1) Warp-knitted mesh base fabric;

[0009] (2) Activation pretreatment of TPU film surface;

[0010] (3) Apply the adhesive to the activated surface of the TPU film obtained in the previous step and dry it;

[0011] (4) Multi-point hot pressing of mesh base fabric and TPU film to obtain TPU / textile composite material;

[0012] (5) Finish and shape the TPU / textile composite material obtained in the previous step.

[0013] Furthermore, in step (1), 20D ultra-fine denier high-strength nylon filament is selected as raw material and woven into a mesh base fabric by a warp knitting machine. The breaking strength of the 20D ultra-fine denier high-strength nylon filament is ≥7.5 cN / dtex, and the fineness variation coefficient is ≤3%. It has excellent mechanical strength and lightweight properties, and as the mechanical support layer of the composite material, it lays the foundation for the lightweight and high strength of the material.

[0014] Furthermore, in step (1), the warp knitting machine weaves a base fabric with a regular and transparent mesh structure by interlocking warp loops and connecting them laterally. Then, the base fabric is heat-set at 100~120℃ and 0.1~0.2 MPa for 3~5 minutes to eliminate the internal stress generated during the base fabric weaving process, ensure the dimensional stability of the base fabric, and avoid shrinkage and deformation during subsequent composite processes.

[0015] The base fabric has a mesh size of 0.1~0.3 mm, a warp knitting density of 20~30 yarns / inch, no weft yarns, an areal density of 30~45 g / m², a thickness of 0.1~0.2 mm, and a breaking elongation of 20%~30%. The material is breathable and soft, and the lightweight and mechanical properties of the base fabric meet the standards, laying the foundation for the lightweighting of the overall composite material.

[0016] Further, in step (2), the TPU film selected is a low-density thermoplastic TPU film with a large number of micron-sized pores, a density of 0.3~0.6 g / cm³, a thickness of 10~20 μm, and a porosity of 15%~25%; it combines softness, breathability, and abrasion resistance, avoiding the material weight gain and hardening problems caused by conventional dense TPU films. The TPU film is subjected to corona activation treatment with a corona power of 3~5 kW and a treatment speed of 5~10 m / min, after which the dyn value of the film surface is increased to 38~42 dyn / cm. The weak interface layer and impurities on the film surface are removed, improving the wettability and adhesion of the film surface, ensuring a firm interface bond with the adhesive and base fabric, and avoiding delamination.

[0017] Further, in step (3), the adhesive is poured into the material trough of the gravure coating machine, and the coating machine parameters are adjusted to ensure that the concave texture of the gravure coating machine adsorbs a certain amount of adhesive. The scraper removes excess adhesive from the surface of the gravure roller. The TPU film to be coated passes through the gravure roller and the traction mechanism, and the adhesive in the concave texture is accurately transferred to the activated surface of the TPU film to achieve uniform coating. The dry coating amount is 5~12 g / m². The coated TPU film is sent into the drying oven and a segmented gradient drying method is adopted. The pre-drying temperature is 80℃ and the time is 1~2 min, the intermediate drying temperature is 100℃ and the time is 1~2 min, and the final drying temperature is 120℃ and the time is 2~3 min. The solvent in the adhesive is completely removed to ensure that the interface is dry and without residue. After drying, the film surface is free of bubbles, wrinkles and adhesive accumulation.

[0018] Furthermore, the adhesive is a low-solids, water-based, environmentally friendly polyurethane adhesive with a solids content of 10%~15% and a viscosity of 100~300 mPa·s at 25°C. It exhibits good compatibility with TPU films and 20D ultra-fine denier high-strength nylon filaments, and does not significantly increase the weight of the material after coating, with no harmful solvent volatilization, meeting the requirements of green production.

[0019] Further, in step (4), the mesh substrate obtained in step (2) and the TPU film obtained in step (3) are precisely aligned, with the coated surface of the TPU film tightly bonded to the mesh substrate. Then, they are fed into a multi-point hot press, employing a non-global, multi-point controllable hot pressing process to achieve a firm fusion of the two interfaces. The hot pressing temperature is 150~170℃, the hot pressing pressure is 0.2~0.4MPa, the hot pressing point density is 5~12 points / cm², the point diameter is 0.3~0.6 mm, and the point shape is circular; the hot pressing time is 3~8 s. The hot pressing temperature is precisely matched to the softening and melting range of the TPU film to avoid excessively high temperatures leading to film degradation and yellowing of the substrate, or excessively low temperatures leading to insufficient interface fusion and insufficient peel strength.

[0020] By using the above-mentioned point-like melting anchoring structure, while ensuring the peel strength at the interface, the material's softness and mesh structure in the non-hot-pressed area are preserved, avoiding problems such as material hardening, weight gain, and decreased wear resistance caused by full-area hot pressing, thus achieving a synergistic balance between peel strength, softness, and lightweight.

[0021] Further, in step (5), the TPU / textile composite material obtained in the previous step is fed into a cold press and cold-pressed for 5 to 10 minutes at 30 to 40°C and 0.1 to 0.2 MPa to eliminate the internal stress generated during the hot processing, further improve the dimensional stability of the composite material, and avoid warping and deformation. A controllable tension winding machine is used to wind up the cold-pressed composite material, and the winding tension is controlled at 50 to 100 N to ensure that the composite material has good flatness, no wrinkles, and no tensile deformation. After winding, it is slit to obtain the finished composite material.

[0022] The present invention also provides a composite material obtained by the preparation method described above.

[0023] The present invention also provides the application of the composite material in the manufacture of high-end trolley cases, backpacks, outdoor bags or briefcases.

[0024] The advantages of this invention are as follows: It uses a 20D ultra-fine denier high-strength nylon filament warp-knitted mesh base fabric as the reinforcing layer and a microporous, low-density thermoplastic polyurethane (TPU) film as the functional layer, resulting in significant lightweight advantages. This effectively reduces the weight of the bag itself, improves portability, and completely solves the problem of insufficient lightweighting in existing technologies. It also boasts excellent abrasion resistance, significantly extending the lifespan of the bag and meeting the abrasion resistance requirements of long-term, high-frequency use. Furthermore, it balances softness and interfacial strength, offering a soft feel and easy shaping, adapting to the needs of the bag's main body and various accessories, overcoming the limitations of existing technologies that "abrasion resistance and lightweight softness cannot be simultaneously achieved." The invention overcomes the technical bottlenecks by using a low-solids water-based environmentally friendly polyurethane adhesive, which has no harmful solvent volatilization, meets the requirements of green production, has high production stability, and is simple, easy to operate, and requires no complex equipment modification, making it convenient for large-scale industrial application. The resulting composite material has multiple advantages such as ultra-lightweight, high wear resistance, softness, strong interface, breathability, and environmental friendliness. It can be widely used in the fabric preparation of various bag products such as high-end trolley cases, backpacks, outdoor bags, and briefcases, and can also be extended to outdoor products, protective equipment, and other fields, with significant industrial application value and market prospects. Detailed Implementation

[0025] The present invention will be described in detail below with reference to specific embodiments. The illustrative embodiments and descriptions of the present invention are used to explain the present invention, but are not intended to limit the present invention.

[0026] Example 1

[0027] This embodiment provides a method for preparing an ultralightweight, highly abrasion-resistant TPU / textile composite material for bags and luggage. The specific steps are as follows:

[0028] Step 1: Selection of raw materials and substrates

[0029] 1.1 Reinforcing base fabric raw material: 20D ultra-fine denier high-strength nylon filaments are selected, with a breaking strength of 7.8 cN / dtex and a fineness variation coefficient of 2.5%;

[0030] 1.2 Functional film: A low-density TPU film with micron-sized pores was selected, with a density of 0.4 g / cm³, a thickness of 15 μm, and a porosity of 20%;

[0031] 1.3 Interface bonding system: Low-solids water-based environmentally friendly polyurethane adhesive is used, with a solids content of 12% and a viscosity of 200 mPa·s (25℃).

[0032] Step 2: Preparation of 20D ultra-fine denier high-strength nylon warp-knitted mesh base fabric

[0033] 2.1 Weaving: A Jacquard-type Raschel warp knitting machine is used to weave 20D ultra-fine denier high-strength nylon filaments into a base fabric with a mesh structure. The mesh size is 0.2 mm and the warp knitting density is 25 threads / inch.

[0034] 2.2 Low-temperature pre-setting: The woven base fabric is placed in a heat setting machine and heat-set at 110℃ and 0.15 MPa for 4 min;

[0035] 2.3 Inspection and control: After shaping, the surface density of the base fabric is 38 g / m², the thickness is 0.15 mm, and the elongation at break is 25%.

[0036] Step 3: Surface pretreatment of TPU film

[0037] The TPU film was subjected to corona activation treatment with a corona power of 4 kW and a treatment speed of 8 m / min. After treatment, the dyn value of the film surface was 40 dyn / cm.

[0038] Step 4: Precision Coating Process

[0039] 4.1 Coating preparation: Pour water-based polyurethane adhesive into the material trough of the gravure coating machine. When the gravure roller rotates, the concave texture on its surface absorbs a certain amount of adhesive; the doctor blade scrapes off the excess adhesive from the surface of the gravure roller.

[0040] 4.2 Coating operation: The TPU film to be coated (after pretreatment) is passed through a gravure roller and a traction mechanism. The adhesive in the concave groove is precisely transferred to the activated surface of the TPU film to achieve uniform coating. The dry coating amount is 8 g / m².

[0041] 4.3 Segmented gradient drying: pre-drying at 80℃ for 1.5 min, intermediate drying at 100℃ for 1.5 min, and final drying at 120℃ for 2.5 min. After drying, the film surface is free of bubbles and wrinkles.

[0042] Step 5: Multi-point controllable hot-press interface fusion

[0043] The coated TPU film is precisely aligned with the base fabric and fed into a multi-point hot press. The hot pressing temperature is 160℃, the hot pressing pressure is 0.3 MPa, the point density is 8 points / cm², the point diameter is 0.45 mm, and the hot pressing time is 5 s.

[0044] Step 6: Finishing and Shaping

[0045] 6.1 Cold pressing and setting: Cold pressing and setting for 8 min at 35℃ and 0.15 MPa;

[0046] 6.2 Tension control and winding: The winding tension is 75 N. After winding, the product is slit to obtain the finished composite material.

[0047] Example 2

[0048] This embodiment provides a method for preparing an ultralightweight, highly abrasion-resistant TPU / textile composite material for bags and luggage. The specific steps are as follows:

[0049] Step 1: Selection of raw materials and substrates

[0050] 1.1 Reinforcing base fabric raw material: 20D ultra-fine denier high-strength nylon filaments are selected, with a breaking strength of 7.5 cN / dtex and a fineness variation coefficient of 3%;

[0051] 1.2 Functional film: A high-density TPU film with micron-level pores was selected, with a density of 0.3 g / cm³, a thickness of 10 μm, and a porosity of 15%;

[0052] 1.3 Interface bonding system: Low-solids water-based polyurethane environmentally friendly adhesive is used, with a solids content of 10% and a viscosity of 100 mPa·s (25℃).

[0053] Step 2: Preparation of 20D ultra-fine denier high-strength nylon warp-knitted mesh base fabric

[0054] 2.1 Weaving: A Jacquard-type Raschel warp knitting machine is used to weave 20D ultra-fine denier high-strength nylon filaments into a base fabric with a mesh structure. The mesh size is 0.1 mm and the warp knitting density is 20 threads / inch.

[0055] 2.2 Low-temperature pre-setting: The woven base fabric is placed in a heat setting machine and heat-set for 3 min at 100℃ and 0.1 MPa;

[0056] 2.3 Inspection and control: After shaping, the surface density of the base fabric is 30 g / m², the thickness is 0.1 mm, and the elongation at break is 20%.

[0057] Step 3: Surface pretreatment of TPU film

[0058] The TPU film was subjected to corona activation treatment with a corona power of 3 kW and a treatment speed of 5 m / min. After treatment, the dyn value of the film surface was 38 dyn / cm.

[0059] Step 4: Precision Coating Process

[0060] The dry coating amount was 5 g / m², and the segmented gradient drying parameters were: pre-drying at 80°C for 1 min, intermediate drying at 100°C for 1 min, and final drying at 120°C for 2 min, with the rest being the same as in Example 1.

[0061] Step 5: Multi-point controllable hot-press interface fusion

[0062] The hot pressing temperature was 150℃, the hot pressing pressure was 0.2 MPa, the spot density was 5 spots / cm², the spot diameter was 0.3 mm, the hot pressing time was 3 s, and the rest was the same as in Example 1.

[0063] Step 6: Finishing and Shaping

[0064] The cold pressing and shaping temperature was 30℃, the pressure was 0.1 MPa, the time was 5 min, the winding tension was 50 N, and the rest was the same as in Example 1, to obtain the finished composite material.

[0065] Example 3

[0066] This embodiment provides a method for preparing an ultralightweight, highly abrasion-resistant TPU / textile composite material for bags and luggage. The specific steps are as follows:

[0067] Step 1: Selection of raw materials and substrates

[0068] 1.1 Reinforcing base fabric raw material: 20D ultra-fine denier high-strength nylon filaments are selected, with a breaking strength of 8.0 cN / dtex and a fineness variation coefficient of 2%;

[0069] 1.2 Functional film: A low-density TPU film with micron-level pores was selected, with a density of 0.6 g / cm³, a thickness of 20 μm, and a porosity of 25%;

[0070] 1.3 Interface bonding system: Low-solids water-based environmentally friendly polyurethane adhesive is used, with a solids content of 15% and a viscosity of 300 mPa·s (25℃).

[0071] Step 2: Preparation of 20D ultra-fine denier high-strength nylon warp-knitted mesh base fabric

[0072] 2.1 Weaving: A Jacquard-type Raschel warp knitting machine is used to weave 20D ultra-fine denier high-strength nylon filaments into a base fabric with a mesh structure. The mesh size is 0.3 mm and the warp knitting density is 30 threads / inch.

[0073] 2.2 Low-temperature pre-setting: The woven base fabric is placed in a heat setting machine with the following parameters: 120℃, 0.2 MPa, 5 min;

[0074] 2.3 Inspection and control: After shaping, the surface density of the base fabric is 45 g / m², the thickness is 0.2 mm, and the elongation at break is 30%.

[0075] Step 3: Surface pretreatment of TPU film

[0076] TPU film was subjected to corona activation treatment with a corona power of 5 kW and a treatment speed of 10 m / min. The surface dyn value of the film after treatment was 42 dyn / cm.

[0077] Step 4: Precision Coating Process

[0078] The dry coating amount was 12 g / m², and the drying was carried out in stages: pre-drying at 80°C for 2 min, intermediate drying at 100°C for 2 min, and final drying at 120°C for 3 min. The rest was the same as in Example 1.

[0079] Step 5: Multi-point controllable hot-press interface fusion

[0080] The hot pressing temperature was 170℃, the hot pressing pressure was 0.4 MPa, the spot density was 12 spots / cm², the spot diameter was 0.6 mm, the hot pressing time was 8 s, and the rest was the same as in Example 1.

[0081] Step 6: Finishing and Shaping

[0082] The cold pressing and shaping temperature was 40℃, the pressure was 0.2 MPa, the time was 10 min, the winding tension was 100 N, and the rest was the same as in Example 1, to obtain the finished composite material.

[0083] Example 4

[0084] This embodiment provides a method for preparing an ultralightweight, highly abrasion-resistant TPU / textile composite material for bags and luggage. The specific steps are as follows:

[0085] Step 1: Selection of raw materials and substrates

[0086] 1.1 Reinforcing base fabric raw material: 20D ultra-fine denier high-strength nylon filaments are selected, with a breaking strength of 7.6 cN / dtex and a fineness variation coefficient of 2.8%;

[0087] 1.2 Functional film: A low-density TPU film with micron-sized pores was selected, with a density of 0.5 g / cm³, a thickness of 18 μm, and a porosity of 22%;

[0088] 1.3 Interface bonding system: Low-solids water-based polyurethane environmentally friendly adhesive is used, with a solids content of 13% and a viscosity of 250 mPa·s (25℃).

[0089] Step 2: Preparation of 20D ultra-fine denier high-strength nylon warp-knitted mesh base fabric

[0090] 2.1 Weaving: A Jacquard-type Raschel warp knitting machine is used to weave 20D ultra-fine denier high-strength nylon filaments into a base fabric with a mesh structure. The mesh size is 0.25 mm and the warp knitting density is 28 threads / inch.

[0091] 2.2 Low-temperature pre-setting: The woven base fabric is placed in a heat setting machine with the following parameters: 115℃, 0.18 MPa, and 4.5 min.

[0092] 2.3 Inspection and control: After shaping, the surface density of the base fabric is 42 g / m², the thickness is 0.18 mm, and the elongation at break is 28%.

[0093] Step 3: Surface pretreatment of TPU film

[0094] The TPU film was subjected to corona activation treatment with a corona power of 4.5 kW and a treatment speed of 9 m / min. The surface dyn value after treatment was 41 dyn / cm.

[0095] Step 4: Precision Coating Process

[0096] The dry coating amount was 10 g / m², and the drying was carried out in stages: pre-drying at 80°C for 1.8 min, intermediate drying at 100°C for 1.8 min, and final drying at 120°C for 2.8 min. The rest was the same as in Example 1.

[0097] Step 5: Multi-point controllable hot-press interface fusion

[0098] The hot pressing temperature was 165℃, the hot pressing pressure was 0.35 MPa, the spot density was 10 spots / cm², the spot diameter was 0.5 mm, the hot pressing time was 6 s, and the rest was the same as in Example 1.

[0099] Step 6: Finishing and Shaping

[0100] The cold pressing and shaping temperature was 38℃, the pressure was 0.18 MPa, the time was 9 min, the winding tension was 90 N, and the rest was the same as in Example 1, to obtain the finished composite material.

[0101] Effect verification experiment

[0102] 1. Experimental Objective

[0103] The core properties (areal density, T-peel strength, Martindale abrasion resistance, and flexural stiffness) of the ultra-lightweight and highly abrasion-resistant TPU / textile composite materials for bags prepared in Examples 1-4 of this invention are verified and compared with those of TPU / textile composite materials for bags prepared by conventional processes (comparative examples) to clarify the technical advantages of this invention.

[0104] 2. Experimental Samples

[0105] Experimental group: Finished composite materials prepared in Examples 1-4 of this invention;

[0106] Comparative example: TPU / textile composite material for bags prepared using conventional processes (base fabric is 50D nylon weft-knitted fabric, TPU film is dense with a density of 1.2 g / cm³, full-area hot-pressing composite process is used, and the adhesive is a high-solids solvent-based adhesive).

[0107] Sample specifications: All samples were cut into standard specimens of 30 cm × 30 cm, with 3 samples in each group, and the average value was taken as the test result.

[0108] 3. Testing

[0109] The relevant performance tests were conducted on the products of Examples 1-4 and the comparative examples, and the results are shown in the table below:

[0110] The test results above show that the composite materials prepared in Examples 1-4 of this invention all have a surface density of <110 g / m², which is much lower than that of the comparative example, demonstrating significant lightweight advantages; their T-peel strength is ≥8 N / 5 cm, which is higher than that of the comparative example, indicating strong interfacial bonding; their Martindale abrasion resistance exceeds 60,000 revolutions, far exceeding that of the comparative example (35,000 revolutions), demonstrating excellent abrasion resistance; and their flexural stiffness is ≤50 mN·cm, lower than that of the comparative example (65 mN·cm), indicating better flexibility. In summary, the preparation method of this invention can effectively achieve a synergistic balance of ultra-lightweight, high abrasion resistance, flexibility, and interfacial strength in composite materials, with performance far exceeding existing conventional process products and industry standards, fully meeting the usage requirements of high-end bags.

[0111] The technical solutions provided by the embodiments of the present invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the embodiments of the present invention. The descriptions of the embodiments above are only for helping to understand the principles of the embodiments of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the embodiments of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for preparing an ultralightweight, highly wear-resistant TPU / textile composite material for bags and luggage, characterized in that, Includes the following steps: (1) Warp-knitted mesh base fabric; (2) Activation pretreatment of TPU film surface; (3) Apply the adhesive to the activated surface of the TPU film obtained in the previous step and dry it; (4) Multi-point hot pressing of mesh base fabric and TPU film to obtain TPU / textile composite material; (5) Finish and shape the TPU / textile composite material obtained in the previous step.

2. The preparation method of the ultralightweight and highly wear-resistant TPU / textile composite material for bags according to claim 1, characterized in that, In step (1), 20D ultra-fine denier high-strength nylon filament is selected as raw material and a mesh base fabric is woven by a warp knitting machine. The breaking strength of the 20D ultra-fine denier high-strength nylon filament is ≥7.5 cN / dtex and the fineness variation coefficient is ≤3%.

3. The method for preparing an ultralightweight, highly wear-resistant TPU / textile composite material for bags according to claim 1 or 2, characterized in that, In step (1), the warp knitting machine weaves a base fabric with a regular, permeable mesh structure by interlacing and laterally connecting warp loops. The base fabric is then heat-set at 100-120℃ and 0.1-0.2 MPa for 3-5 minutes. The base fabric has a mesh size of 0.1~0.3 mm, a warp knitting density of 20~30 yarns / inch, no weft yarns, an areal density of 30~45 g / m², a thickness of 0.1~0.2 mm, and a breaking elongation of 20%~30%.

4. The method for preparing an ultralightweight, highly wear-resistant TPU / textile composite material for bags according to claim 1, characterized in that, In step (2), the TPU film is a low-density thermoplastic TPU film with a large number of micron-sized pores, a density of 0.3~0.6 g / cm³, a thickness of 10~20 μm, and a porosity of 15%~25%. The TPU film is subjected to corona activation treatment with a corona power of 3~5 kW and a treatment speed of 5~10 m / min. After treatment, the dyn value of the film surface is increased to 38~42 dyn / cm.

5. The method for preparing an ultralightweight, highly wear-resistant TPU / textile composite material for bags according to claim 1, characterized in that, In step (3), the adhesive is poured into the material trough of the gravure coating machine, and the parameters of the coating machine are adjusted to ensure that the concave texture of the gravure coating machine adsorbs a certain amount of adhesive. The scraper removes the excess adhesive from the surface of the gravure roller. The TPU film to be coated passes through the gravure roller and the traction mechanism, and the adhesive in the concave texture is accurately transferred to the activated surface of the TPU film to achieve uniform coating. The dry coating amount is 5~12 g / m². The coated TPU film is sent into the drying oven and a segmented gradient drying method is adopted. The pre-drying temperature is 80℃ and the time is 1~2 min, the intermediate drying temperature is 100℃ and the time is 1~2 min, and the final drying temperature is 120℃ and the time is 2~3 min.

6. The method for preparing an ultralightweight, highly abrasion-resistant TPU / textile composite material for bags according to claim 1 or 5, characterized in that, The adhesive is a low-solids water-based environmentally friendly polyurethane adhesive with a solids content of 10% to 15% and a viscosity of 100 to 300 mPa·s at 25°C.

7. The method for preparing an ultralightweight, highly wear-resistant TPU / textile composite material for bags according to claim 1, characterized in that, In step (4), the mesh base fabric obtained in step (2) and the TPU film obtained in step (3) are precisely aligned, and the coated surface of the TPU film is tightly bonded to the mesh base fabric. Then, the TPU film is fed into a multi-point hot press and a non-global, multi-point controllable hot pressing process is used to achieve a firm fusion of the two interfaces. The hot pressing temperature is 150~170℃, the hot pressing pressure is 0.2~0.4 MPa, the hot pressing point density is 5~12 points / cm², the point diameter is 0.3~0.6 mm, and the point shape is circular. The hot pressing time is 3~8 s.

8. The method for preparing an ultralightweight, highly wear-resistant TPU / textile composite material for bags according to claim 1, characterized in that, In step (5), the TPU / textile composite material obtained in the previous step is fed into a cold press and cold-pressed for 5 to 10 minutes at 30 to 40°C and 0.1 to 0.2 MPa. A controllable tension winding machine is used to wind up the cold-pressed composite material, with the winding tension controlled at 50 to 100 N. After winding, the composite material is cut to obtain the finished composite material.

9. The composite material obtained by any one of the preparation methods described in claims 1-8.

10. The application of the composite material as described in claim 9 in the manufacture of high-end trolley cases, backpacks, outdoor bags, or briefcases.

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