A tpu film and non-woven fabric composite for a lumbar support and a method of manufacturing the same

Abstract

The present application relates to the technical field of composite materials, in particular to a TPU film and non-woven fabric composite material for a waist support and a preparation method thereof, at least comprising a non-woven fabric and a TPU film, the non-woven fabric and the TPU film are prepared into a composite material through online compounding or glue bonding, and the preparation raw material of the TPU film is TPU particles, the composite material has low cost, excellent comprehensive performance, and meets the application requirements of the waist support air bag better in the production process of composite environmental protection sustainability.

Description

Technical Field

[0001] This invention relates to the field of composite material technology, specifically to a composite material of TPU film and nonwoven fabric for lumbar support and its preparation method. Background Technology

[0002] As a crucial interior system in automobiles, car seat systems are constantly evolving with advancements in automotive technology, leading to continuous upgrades in seat comfort technology. Lumbar support and massage airbags, which significantly reduce driver fatigue and thus enhance driving comfort and safety, are gradually becoming standard features in car seats, widely used not only in high-end models but also in mid-to-low-end vehicles. However, existing lumbar support airbags are generally made of PVC film (polyvinyl chloride), a choice that presents several problems: First, the production process is not environmentally friendly and may release toxic gases at high temperatures, posing a potential threat to passengers and the environment; second, PVC material is relatively hard, causing the airbag to easily rub against surrounding leather and parts during use, generating noise that affects both ride comfort and the overall quality of the vehicle—a problem that urgently needs to be addressed; third, PVC has low strength and cannot withstand high air pressure, and repeated inflation and deflation can cause the PVC to change size, resulting in the lumbar support airbag losing its shape and proper support during use. For example, Chinese patent (publication number CN106939071A) discloses a TPU composite material for car massage and its preparation method. It mainly optimizes the TPU formulation, uses polyether polyol and polyester polyol as raw materials and a specific combination of diisocyanate to prepare TPU film, and then combines it with nylon cloth to prepare a composite material with excellent air permeability, moisture permeability and wear resistance. However, further improvements are needed in noise reduction and cost control. Summary of the Invention

[0003] To address the aforementioned issues, this invention provides a composite material of TPU film and nonwoven fabric for lumbar support. This composite material is low in cost, has excellent overall performance, and its production process meets the requirements of environmental protection and sustainability, thus better meeting the application needs of lumbar support airbags.

[0004] The present invention provides a composite material of TPU film and nonwoven fabric for lumbar support, comprising at least nonwoven fabric and TPU film, wherein the nonwoven fabric and TPU film are prepared by online lamination or adhesive bonding, and the raw materials for preparing TPU film include at least TPU particles.

[0005] As a preferred technical solution, the thickness of the composite material of TPU film and nonwoven fabric used for lumbar support is 0.50-1.00mm, preferably 0.50-0.75mm.

[0006] As a preferred technical solution, the TPU film has 1-10 layers, preferably 1 layer.

[0007] As a preferred technical solution, the thickness of the TPU film is 0.20-0.30 mm, preferably 0.20-0.25 mm.

[0008] As a preferred technical solution, the TPU particles are polyether-type TPU particles.

[0009] Preferably, the hardness of the polyether-type TPU particles is 75-97A, and more preferably 85-95A.

[0010] Preferably, the polyether-type TPU particles are selected from Lubrizol 58315, Lubrizol 58887, Lubrizol 58219, Lubrizol R195A, Huafeng HF-4385A, Huafeng HF-4390A, and Huafeng HF-4395A.

[0011] As a preferred technical solution, the nonwoven fabric has a thickness of 0.35-0.5 mm and a weight per square meter of 100-120 g / m². 2 .

[0012] This invention addresses the problems of existing lumbar support airbag materials using PVC, which suffer from environmentally unfriendly production processes, noise generation, and dimensional deformation after repeated inflation and deflation leading to decreased lumbar support strength and shortened material quality and lifespan. Initially, replacing PVC with TPU addressed these shortcomings, including environmental issues, insufficient strength, and VOC non-compliance. However, this still failed to effectively solve the noise problem caused by friction with surrounding leather and parts during use. During the research process, the inventors unexpectedly discovered that by controlling the hardness of polyether-type TPU particles to 85-95A and further laminating them with a certain thickness and weight of nonwoven fabric, the noise problem was effectively solved, while simultaneously improving the overall quality and stability of the lumbar support airbag, extending its lifespan, and significantly reducing costs. This provides a promising direction for future technology development in automotive seat lumbar support airbag materials. The inventors believe the reason for this is that the TPU + nonwoven fabric composite structure effectively reduces friction between the lumbar support airbag and surrounding components, significantly reducing noise and thus improving overall comfort and the driving experience. Simultaneously, it provides stable support performance for the lumbar support airbag product, ensuring that the airbag achieves the required support effect without excessive expansion when inflated. This reduces the airbag's volume expansion rate and effectively suppresses dimensional deformation after multiple inflations and deflations, maintaining stable lumbar support force and ensuring continuous comfort and safety. Furthermore, since a single layer of TPU requires a relatively thick layer (0.35-0.40mm) to achieve an inflation effect, combining the TPU film with non-woven fabric reduces the thickness of the TPU film in the composite material to 0.20-0.25mm. This significantly reduces the cost of TPU raw materials while achieving the same inflation effect, and also helps improve production efficiency, further reducing overall manufacturing costs.

[0013] The TPU film and non-woven fabric composite material provided by this invention combines the wear resistance, good elasticity, stable performance at different temperatures, environmental protection and non-toxicity, and will not cause harm to the human body with the characteristics of TPU. It also combines the advantages of non-woven fabric, such as good strength, breathability and waterproofness, environmental protection, flexibility, non-toxicity and odorlessness, and low price, which can realize large-scale application and promotion.

[0014] Another aspect of the present invention provides a method for preparing a composite material of TPU film and nonwoven fabric for lumbar support, comprising at least the following steps: feeding TPU particles into a dehumidifying dryer for dehumidification and drying to obtain pretreated TPU particles; feeding the pretreated TPU particles into a screw extruder; melting the pretreated TPU particles and extruding them into a film through a die; casting the film onto the nonwoven fabric to form a TPU film; then pressing the film with pressure rollers; cooling and shaping the film; and finally winding it up to obtain the composite material.

[0015] As a preferred technical solution, the dehumidification and drying temperature is 95-100℃, and the time is ≥4h.

[0016] As a preferred technical solution, the moisture content of the pretreated TPU particles is <0.02wt%.

[0017] As a preferred technical solution, the screw temperature of the screw extruder is 180-210℃, and the die temperature is 200-220℃.

[0018] As a preferred technical solution, the pressure of the pressure roller is 2-3 kg / cm². 2 The temperature of the pressure roller is 50-70℃. Preferably, the pressure of the pressure roller is 2.5-2.8 kg / cm². 2 The temperature of the pressure roller is 60-70℃.

[0019] This invention achieves efficient one-step molding by directly casting TPU onto nonwoven fabric. Compared with the traditional adhesive bonding method, it simplifies the production process, greatly improves production efficiency, and further controls the TPU film thickness and pressure roller conditions to ensure that the bonding strength between the TPU film and the nonwoven fabric meets the requirements of subsequent high-frequency welding for the production of lumbar support airbag products. It also avoids the delamination of the TPU film and nonwoven fabric due to insufficient bonding strength.

[0020] Beneficial effects

[0021] 1. This invention provides a composite material of TPU film and non-woven fabric for lumbar support. This composite material has low cost, excellent comprehensive performance, and the production process meets the requirements of environmental protection and sustainability, which can better meet the application needs of lumbar support airbags.

[0022] 2. This invention, by controlling the hardness of polyether-type TPU particles to 85-95A and further compounding them with nonwoven fabric of a certain thickness and square gram weight, effectively solves the noise problem while improving the overall quality and stability of the lumbar support airbag product, extending its service life, and significantly reducing costs, thus providing a certain development direction for the future technology of automotive seat lumbar support airbag materials.

[0023] 3. This invention achieves efficient one-step molding by directly casting TPU onto nonwoven fabric. Compared with the traditional adhesive bonding method, it simplifies the production process, greatly improves production efficiency, and further controls the TPU film thickness and pressure roller conditions to ensure the strong bonding between the TPU film and the nonwoven fabric, meeting the requirements of subsequent high-frequency welding for the production of lumbar support airbag products. Attached Figure Description

[0024] Figure 1This is a schematic diagram of the composite material structure of TPU film and nonwoven fabric for lumbar support provided by the present invention. In the figure, 1 is TPU film and 2 is nonwoven fabric.

[0025] Figure 2 The figures shown are actual product images of the composite material of TPU film and nonwoven fabric for lumbar support provided in Embodiments 1 and 2 of the present invention. In the figures, a represents Embodiment 1 and b represents Embodiment 2.

[0026] Figure 3 A schematic diagram of the shape of the lumbar support provided by the present invention, which is a composite material of TPU film and non-woven fabric welded using high-frequency welding technology.

[0027] Figure 4 This is a picture of a standard lumbar support airbag product. Detailed Implementation

[0028] Example 1

[0029] See Figure 1 , Figure 2 In one aspect, Embodiment 1 of the present invention provides a composite material of TPU film and non-woven fabric for lumbar support, which is prepared by online composite of non-woven fabric 2 and TPU film 1, and the raw material for preparing TPU film is TPU particles.

[0030] The thickness of the composite material of the TPU film and nonwoven fabric used for the lumbar support is 0.70 mm.

[0031] The TPU film has one layer and a thickness of 0.20 mm.

[0032] The TPU particles are polyether-type TPU particles with a hardness of 85A and a model number of Lubrizol 58315.

[0033] The nonwoven fabric has a thickness of 0.5 mm and a weight of 120 g / m². 2 .

[0034] In another aspect, Embodiment 1 of the present invention provides a method for preparing a composite material of TPU film and nonwoven fabric for lumbar support, comprising the following steps: feeding TPU particles into a dehumidifying dryer for dehumidification and drying to obtain pretreated TPU particles; feeding the pretreated TPU particles into a screw extruder; melting the pretreated TPU particles and extruding them into a film through a die; casting the film on the nonwoven fabric to form a TPU film; then pressing the film with pressure rollers; cooling and shaping the film; and finally winding it up to obtain the composite material.

[0035] The dehumidification and drying process is carried out at a temperature of 100°C for 4 hours.

[0036] The moisture content of the pretreated TPU particles is <0.02wt%.

[0037] The screw temperature of the screw extruder is 200℃, and the die temperature is 210℃.

[0038] The pressure of the pressure roller is 2.8 kg / cm. 2 The temperature of the pressure roller is 60℃.

[0039] Example 2

[0040] See Figure 1 , Figure 2 In one aspect, Embodiment 2 of the present invention provides a composite material of TPU film and non-woven fabric for lumbar support, which is prepared by online composite of non-woven fabric 2 and TPU film 1, and the raw material for preparing TPU film is TPU particles.

[0041] The thickness of the composite material of the TPU film and nonwoven fabric used for the lumbar support is 0.55 mm.

[0042] The TPU film has one layer and a thickness of 0.20 mm.

[0043] The TPU particles are polyether-type TPU particles with a hardness of 95A and a model number of Lubrizol R195A.

[0044] The nonwoven fabric has a thickness of 0.35 mm and a weight per square meter of 100 g / m². 2 .

[0045] Another aspect of the present invention, embodiment 2, provides a method for preparing a composite material of TPU film and nonwoven fabric for lumbar support, comprising the following steps: feeding TPU particles into a dehumidifying dryer for dehumidification and drying to obtain pretreated TPU particles; feeding the pretreated TPU particles into a screw extruder; melting the pretreated TPU particles and extruding them into a film through a die; casting the film onto the nonwoven fabric to form a TPU film; then pressing the film with pressure rollers; cooling and shaping the film; and finally winding it up to obtain the composite material.

[0046] The dehumidification and drying process is carried out at a temperature of 100°C for 4 hours.

[0047] The moisture content of the pretreated TPU particles is <0.02wt%.

[0048] The screw temperature of the screw extruder is 210°C, and the die temperature is 220°C.

[0049] The pressure of the pressure roller is 2.5 kg / cm. 2 The temperature of the pressure roller is 70℃.

[0050] Comparative Example 1

[0051] Comparative Example 1 of the present invention provides a composite material of TPU film and nylon cloth, which is prepared by online composite of nylon cloth and TPU film, and the raw material for preparing TPU film is TPU particles.

[0052] The thickness of the composite material of the TPU film and nylon cloth is 0.55 mm.

[0053] The TPU film has one layer and a thickness of 0.20 mm.

[0054] The TPU particles are polyether-type TPU particles with a hardness of 95A and a model number of Lubrizol R195A.

[0055] The nylon fabric is 70D nylon fabric.

[0056] The method for preparing the composite material of TPU film and nylon cloth includes the following steps: feeding TPU particles into a dehumidifying dryer to dehumidify and dry them to obtain pretreated TPU particles; feeding the pretreated TPU particles into a screw extruder; melting the pretreated TPU particles and extruding them into a film through a die; casting the film onto the nylon cloth to form a TPU film; pressing the film with pressure rollers; cooling and shaping the film; and then winding it up to obtain the composite material.

[0057] The dehumidification and drying process is carried out at a temperature of 100°C for 4 hours.

[0058] The moisture content of the pretreated TPU particles is <0.02wt%.

[0059] The screw temperature of the screw extruder is 210°C, and the die temperature is 220°C.

[0060] The pressure of the pressure roller is 2.5 kg / cm. 2 The temperature of the pressure roller is 70℃.

[0061] Comparative Example 2

[0062] Comparative Example 2 of the present invention provides a composite material of TPU film and nonwoven fabric and its preparation method. The specific implementation method is the same as that of Example 2, except that the polyether-type TPU particles are replaced with R198A with a hardness of 98A.

[0063] Comparative Example 3

[0064] Comparative Example 3 of the present invention provides a composite material of TPU film and nonwoven fabric and its preparation method. The specific implementation method is the same as in Example 2, except that the thickness of the composite material of TPU film and nonwoven fabric is 0.45 mm, the thickness of the TPU film is 0.10 mm, and the pressure of the pressure roller is 1.5 kg / cm². 2 After winding, it was observed that the TPU film delaminated directly from the nonwoven fabric, and no further performance tests were conducted.

[0065] Comparative Example 4

[0066] Comparative Example 4 of the present invention provides a composite material of TPU film and nonwoven fabric and its preparation method. The specific implementation method is the same as that of Example 2, except that the thickness of the composite material of TPU film and nonwoven fabric is 0.45 mm and the thickness of TPU film is 0.10 mm. When the high-frequency welding strength test is performed, the peeling point is the peeling of TPU film and nonwoven fabric. The strength is insufficient, so no other tests are performed.

[0067] Performance testing methods

[0068] The products provided in Examples 1 and 2, Comparative Examples 1 and 2, and the PVC film (1.0 mm thick) and TPU film (0.60 mm thick) used as controls were subjected to tensile strength, 100% modulus, elongation at break, 45 kPa inflation test, VOC test, noise test, and high-frequency welding strength test (the products were welded into a waist support shape using high-frequency welding technology, see [reference]). Figure 3 , Figure 4 The price and cost assessment, test reference standards and related results are shown in Table 1.

[0069] Table 1

[0070]

[0071] (Note: "+" indicates the noise level and price; more "+" signs mean greater noise and higher price.)

[0072] The test results show that:

[0073] To address the environmental issues, insufficient strength, and VOC non-compliance of PVC and its lumbar support products, we attempted to use single-layer TPU film as a substitute, effectively solving these problems. However, single-layer TPU still faces issues of thickness and deformation during repeated inflation and deflation in inflatable applications. Therefore, we introduced a composite structure of TPU film and non-woven fabric. Through a series of experiments, this composite material not only significantly reduced noise levels but also achieved a reduction in TPU thickness through the non-woven fabric composite, while maintaining dimensional stability after inflation. With the increase in non-woven fabric thickness and basis weight, the tensile strength and high-frequency welding strength of the composite material also increased accordingly, further improving the support effect of the lumbar support airbag. In contrast, although existing TPU and nylon fabric composite structures perform well in terms of wear resistance and breathability, their high noise and cost limit their market adoption.

[0074] In conclusion, TPU film and nonwoven fabric composites have become a more cost-effective and preferred solution in the field of lumbar support materials due to their environmental friendliness, noise reduction performance, dimensional stability and cost advantages.

Claims

1. A composite material of TPU film and nonwoven fabric for lumbar support, characterized in that, The composite material comprises at least a nonwoven fabric and a TPU film, which are prepared by online lamination. The TPU film is prepared from at least TPU particles, has one layer, a thickness of 0.20-0.30 mm, and the TPU particles are polyether-type TPU particles with a hardness of 75-97A. The nonwoven fabric has a thickness of 0.35-0.5 mm and a basis weight of 100-120 g / m². g / m²; the thickness of the TPU film and nonwoven fabric composite material for the lumbar support is 0.50-1.00 mm; the preparation method of the TPU film and nonwoven fabric composite material for the lumbar support includes at least the following steps: feeding TPU particles into a dehumidifying dryer for dehumidification and drying to obtain pretreated TPU particles; feeding the pretreated TPU particles into a screw extruder; after the pretreated TPU particles melt, extruding the film through a die; casting the film on the nonwoven fabric; then pressing the film through a pressure roller; cooling and shaping the film; and finally winding it up to obtain the composite material; the screw temperature of the screw extruder is 180-210℃, and the die temperature is 200-220℃; the pressure of the pressure roller is 2-3 kg / cm², and the pressure roller temperature is 50-70℃.

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