Device and method for modular production of TPU authigenic texture membrane

Abstract

The invention relates to the technical field of thermoplastic polyurethane (TPU) processing, in particular to a device and a method for modularly producing a TPU authigenic texture membrane, which are characterized in that a complex texture generation process is linked with a plurality of modules with independent functions, and accurate digital control on key process parameters is realized in each module, so that the production efficiency of the TPU authigenic texture membrane is improved. Therefore, the seemingly random'authigenic 'process is converted into a highly controllable and programmable technological process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of thermoplastic polyurethane (TPU) processing, in particular to a device and method for modular production of TPU self-generated textured film. BACKGROUND

[0002] Thermoplastic polyurethane (TPU) is widely used in shoe materials, clothing, luggage, electronic products and automobiles due to its excellent elasticity, wear resistance, low temperature resistance and high strength. Aliphatic TPU is favored in high-end appearance parts due to its excellent anti-yellowing performance and weather resistance. In order to improve the added value of products, the market has higher requirements for the appearance of TPU film, expecting it to have unique texture similar to marble or fritillary, and at the same time have the elasticity and touch of natural leather.

[0003] In the prior art, the texture of TPU film is usually obtained by physical methods such as mold etching or surface embossing. These methods have limitations, especially the texture lacks randomness and uniqueness, and the durability of the texture is poor. In view of these problems, the present application proposes a new modular production device and method, which can accurately control the formation of texture during production and ensure that the texture of each batch of products has uniqueness and controllability. SUMMARY

[0004] The first object of the present application is to provide a device for modular production of TPU self-generated textured film, which links multiple functionally independent modules to the complex texture generation process, and realizes accurate digital control of key process parameters in each module, thereby transforming the seemingly random "self-generated" process into a highly controllable and programmable process flow.

[0005] To achieve the above object, the present application adopts the following technical scheme: A device for modular production of TPU self-generated textured film, comprising a plurality of functionally independent modules arranged and connected in sequence along the production process flow, wherein the modules include: A raw material pretreatment and accurate color matching module for drying and surface activation of aliphatic TPU base material at 80-100℃ for 4 hours, and realizing accurate metering and premixing with functional masterbatch, wherein the proportion of color masterbatch is accurately controlled between 1-5%; A structured blending and texture induction module including a co-rotating twin-screw extruder configured with at least four temperature control sections and provided with at least one side feeder, the temperature control sections are controlled at 160-200℃, and TPU and color masterbatch are melt blended at a shear rate of 300-500 rpm, and a texture module is formed by mold channel induced extrusion, and the formation path of the texture is controlled by the compatibility design of TPU; Dynamic casting and speed and temperature control module: including a controllable temperature casting roller group, the casting roller temperature is controlled in the range of 40-70℃, and a speed adjusting device is arranged for accurately controlling the stretching rate of the film, and a cooling device is provided to blow and cool the film to ensure the stability of the texture; Programmed solidification and texture shaping module: including a cooling device with gradient cooling function, at least three temperature intervals are set, and the cooling rate is controlled in the range of 3-10℃ / min, for the film to complete the final crystallization and texture shaping under the set tension and temperature curve.

[0006] The advantage of the present application is that by linking the complex texture generation process to multiple functionally independent modules and implementing precise digital control of key process parameters in each module, the seemingly random "self-generating" process is transformed into a highly controllable, programmable process flow.

[0007] The second object of the present application is to provide a method for modular production of TPU self-generating texture film by linking the complex texture generation process to multiple functionally independent modules and implementing precise digital control of key process parameters in each module, thereby transforming the seemingly random "self-generating" process into a highly controllable, programmable process flow.

[0008] To achieve the above object, the present application adopts the following technical scheme: A method for modular production of TPU self-generating texture film using the above-mentioned device, comprising the following steps: Raw material pretreatment and color matching: dry the selected aliphatic TPU base material at 80-100℃ for 4 hours, then mix it with color masterbatch in a high-speed mixer according to the set proportion (1-5%) to ensure uniform distribution of the color masterbatch and TPU base material and maintain the accuracy of color matching; S2: structured blending and texture induction: feed the premixed material into the co-rotating twin-screw extruder through the main feeder, control the temperature of each section of the extruder between 160-200℃, and set the screw speed at 300 rpm to provide the required high shear rate; during the extrusion process, different mold channels are used to induce extrusion to form the set texture structure, and after cooling, the components are not adhered to facilitate subsequent stretching and molding; S3: dynamic casting and speed and temperature control: cast the extruded melt through a T-shaped die to a cooling roller, control the cooling roller temperature between 40-70℃; at the same time, start the cooling device to blow dry air at room temperature (25℃) to the surface of the film through the blowing device, with a wind speed of 2 m / s, to ensure the stable formation of the texture on the film surface; S4: Programmed Curing and Texture Shaping: After casting, the film enters the programmed curing module and is pulled under a set gradient cooling path and constant tension. Specifically, it includes three cooling zones: the first stage is 80℃ (30 seconds), the second stage is 50℃ (30 seconds), and the third stage is room temperature (air cooling). During this process, the film is modularly shaped to complete the final crystallization and solidify the texture structure.

[0009] The advantage of this invention lies in linking the complex texture generation process with multiple functionally independent modules and implementing precise digital control of key process parameters in each module, thereby transforming the seemingly random "self-generated" process into a highly controllable and programmable process flow. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the overall structure of the TPU modular production system in an embodiment of the present invention; Figure 2 This is a schematic diagram of the texture shaping module in an embodiment of the present invention; Figure 3 and Figure 4 This is a physical image of an aliphatic TPU self-textured film produced using the method of this invention. Detailed Implementation

[0011] As attached Figure 1 As shown, a modular apparatus for producing TPU self-textured films includes components sequentially arranged and connected along the production process flow: Raw material pretreatment and precise color matching module 101: used to dry and surface activate aliphatic TPU base material at 80-100℃ for 4 hours, and to achieve precise metering and premixing with functional masterbatch, wherein the proportion of color masterbatch is precisely controlled between 1-5%. The structured blending and texture-inducing module 102 includes a co-rotating twin-screw extruder with at least four temperature-controlled zones and at least one side feeder. The temperature in each temperature-controlled zone is maintained between 160-200°C. TPU and color masterbatch are melt-blended at a shear rate of 300-500 rpm, and extruded through a die channel to form a texture module. The texture formation path is controlled by the TPU's compatibility design. The texture-inducing module uses different TPU materials and die designs to create controllable texture morphology features, with the die design determining the texture morphology. The twin-screw extruder in the structured blending and texture-inducing module, under high shear rate and specific temperature control, uniformly disperses color masterbatch in the TPU base material to form a specified texture structure.

[0012] The dynamic casting and speed and temperature control module 103 includes a temperature-controlled casting roller group, with the casting roller temperature controlled within the range of 40-70℃, and a speed adjustment device for precisely controlling the stretching rate of the film. It is also equipped with a cooling device to perform air cooling treatment on the film to ensure the stability of the texture. The dynamic casting and speed and temperature control module controls the final texture shape and specifications of the film by adjusting the casting speed of 0.5-5 m / min, the casting roller temperature of 40-70℃, and the cooling rate of the film surface.

[0013] The programmed curing and texture setting module 104 includes a cooling device with a gradient cooling function, setting at least three temperature ranges, and controlling the cooling rate within the range of 3-10℃ / minute. This allows the film to complete final crystallization and texture setting under a set tension and temperature curve. The gradient cooling function of the programmed curing and texture setting module includes setting at least three temperature ranges: 80℃ (30 seconds), 50℃ (30 seconds), and room temperature (air cooling), to ensure that the texture is stably "frozen" inside the film. The texture setting module is attached. Figure 2 As shown, the components are arranged in a pre-designed module according to a programmed solidification process. In this process, the first layer of mold is on the left, the second layer of mold is on the right, the third layer of mold is on the left, and so on, so that the molds of adjacent layers are arranged in an alternating manner to achieve the shaping of the texture.

[0014] After the membrane completes its final crystallization and texture shaping under the set tension and temperature curves, it undergoes the processes of conventional cavity pressing 105, shaving 106, and leveling 107 in sequence to finally form the product.

[0015] A method for producing a TPU self-textured film using the above-described device includes the following steps: S1: Raw material pretreatment and color matching: Dry the selected aliphatic TPU base material at 80-100℃ for 4 hours, and then put it into a high-speed mixer for premixing with the color masterbatch at a set ratio (1-5%) to ensure the uniform distribution of the color masterbatch and TPU base material and maintain the accuracy of color matching. S2: Structured blending and texture induction: The premixed material is fed into a co-rotating twin-screw extruder through the main feeder. The temperature of each section of the extruder is controlled between 160-200℃, and the screw speed is set to 300 rpm to provide the required high shear rate. During the extrusion process, different die channels are used to induce extrusion and form the set texture structure. After cooling, the components do not stick together, which facilitates subsequent stretching and molding. S3: Dynamic casting and speed and temperature control: The extruded melt is cast to the cooling roller through the T-die, and the temperature of the cooling roller is controlled between 40-70℃; at the same time, the cooling device is activated, and dry air at room temperature (25℃) is blown onto the film surface by the blowing device at a wind speed of 2 m / s to ensure the stable formation of texture on the film surface. S4: Programmed Curing and Texture Shaping: After casting, the film enters the programmed curing module and is pulled under a set gradient cooling path and constant tension. Specifically, it includes three cooling zones: the first stage is 80℃ (30 seconds), the second stage is 50℃ (30 seconds), and the third stage is room temperature (air cooling). During this process, the film is modularly shaped to complete the final crystallization and solidify the texture structure.

[0016] In step S2, different feeders inject different set color combinations, wherein the proportion of each color is controlled between 1-5% to ensure the diversity of the final texture and the uniformity of the color.

[0017] In step S2, the temperature of each section of the extruder is controlled between 160-200℃, and the screw speed is set to 300 rpm to provide the required high shear rate. During this process, different set color combinations are injected through multiple feeders, with the proportion of color masterbatch in each feeder controlled between 1-5%, ensuring that each color is evenly distributed in the TPU base material. Extrusion is induced through different die channels to form the set texture structure, and cooling prevents the components from sticking together, facilitating subsequent stretching and molding. The final product is shown in the attached image. Figure 3 and Figure 4 As shown.

[0018] First example: Raw material pretreatment and precise color matching module: Aliphatic TPU is dried in a vacuum oven (90℃, 4h), and then added to a mixer along with 1.5% of No. 1 gold masterbatch, and mixed at low speed for 5 minutes. This process is repeated to prepare No. 2 light green and No. 3 transparent colors.

[0019] Structured blending and texture induction module: Employs a co-rotating twin-screw extruder (L / D ratio 40:1). Temperature profile settings: Zone 1 165℃, Zone 2 175℃, Zone 3 185℃, Zone 4 190℃, Zone 5 185℃, Zone 6 180℃. Add the premixed material through feeder 1, the light green material (No. 2) through feeder 2, and the transparent material (No. 3) through feeder 3. Set the screw speed to 300 rpm to provide high shear.

[0020] Dynamic casting with speed and temperature control module: After the melt is extruded from the T-die, it is cast onto the first cooling roller and the second cooling roller. At the same time, the cooling device is activated, blowing dry air onto the film surface at a speed of 2 m / s.

[0021] Programmed curing and texture setting module: The membrane then enters a three-stage gradient cooling chamber: the first stage at 80°C (30 seconds), the second stage at 50°C (30 seconds), and the third stage at room temperature (air cooling). Modular secondary shaping is used to enable the texture component to complete the final crystallization and texture setting under the set tension and temperature curves.

[0022] Using the aforementioned apparatus and process, the resulting membrane components exhibit an orderly distribution of different shades of golden-green base material. These components are then melted and formed into a cake-like shape using a mold cavity under high temperature and pressure. Finally, the cake is sliced ​​using a machine tool to obtain membranes with a surface exhibiting random, flowing golden textures resembling ocean waves. The surface is smooth to the touch, and the texture is integrated with the membrane, making it impossible to scrape off. While all membranes in this batch exhibit a consistent macroscopic texture, each microscopic detail is unique, achieving "family uniqueness."

[0023] Second example: To achieve a more refined, three-dimensional texture effect, some steps were adjusted based on the first example as follows: In the raw material pretreatment and precise color matching, the masterbatch was replaced with Mother-of-Pearl White No. 1, Mother-of-Pearl White No. 2, and Iridescent Mother-of-Pearl Gold No. 3.

[0024] In the texture induction module, the screw speed is reduced to 250 rpm to reduce the degree of texture deformation.

[0025] Maintain the temperature of the first cooling roller to avoid overcooling and ensure stable component texture formation.

[0026] Turn off the heating function of the temperature control device and switch to blowing room temperature air at 25°C.

[0027] Modular secondary modeling is used to enable texture components to complete final crystallization and texture melting followed by cooling and crystallization under set tension and temperature curves.

[0028] The resulting membrane has a more refined surface texture and a stronger three-dimensional feel, successfully simulating the texture of natural fritillary bulb.

[0029] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A modular apparatus for producing a TPU self-textured film, comprising: The process comprises the following modules arranged in sequence along the production process: A raw material pretreatment and precise color matching module: used for drying and surface activation of aliphatic TPU base material in an environment of 80-100℃ for 4 hours, and realizing accurate metering and premixing with functional masterbatch, wherein the proportion of color masterbatch is accurately controlled between 1-5%; A structured blending and texture induction module: comprising a co-rotating twin-screw extruder, configured with at least four temperature control sections, and provided with at least one side feeder, the temperature control section is controlled between 160-200℃, the TPU and color masterbatch are melt blended at a shear rate of 300-500 rpm, and the texture module is formed by mold channel induced extrusion, and the formation path of the texture is controlled by the compatibility design of TPU; A dynamic casting and speed and temperature regulation module: comprising a controllable temperature casting roller group, the casting roller temperature is controlled in the range of 40-70℃, and a speed adjusting device is arranged for accurately controlling the stretching rate of the film, and a cooling device is provided to blow dry air to the film surface to ensure the stability of the texture; A programmed curing and texture setting module: comprising a cooling device with gradient cooling function, at least three temperature intervals are set, and the cooling rate is controlled in the range of 3-10℃ / min, which is used to make the film complete the final crystallization and texture setting under the set tension and temperature curve.

2. A modular apparatus for producing a self-textured TPU film according to claim 1, wherein, The texture induction module forms controllable texture morphological characteristics by selecting different TPU materials and mold designs.

3. The apparatus of claim 1, wherein, The double screw extruder of the structured blending and texture induction module uniformly disperses the color masterbatch in the TPU base material under high shear rate and specific temperature control to form the specified texture structure.

4. The apparatus of claim 1, wherein, The dynamic casting and speed and temperature regulation module regulates the final texture form and specification of the film by casting speed of 0.5-5 m / min, casting roller temperature of 40-70℃, and cooling rate of the film surface.

5. The apparatus of claim 1, wherein, The gradient cooling function of the programmed curing and texture setting module includes setting at least three temperature intervals, which are 80℃, 50℃ and room temperature respectively.

6. A method of producing a TPU self-textured film by using the device module according to any one of claims 1-5, characterized in that, The process comprises the following steps: S1: raw material pretreatment and color matching: dry the selected aliphatic TPU base material at 80-100℃ for 4 hours, then put it into a high-speed mixer with color masterbatch according to the set proportion for premixing, to ensure uniform distribution of color masterbatch and TPU base material and maintain the accuracy of color matching; S2: structured blending and texture induction: put the premix into the co-rotating twin-screw extruder through the main feeder, control the temperature of each section of the extruder between 160-200℃, and set the screw speed to 300 rpm to provide the required high shear rate; during the extrusion process, different mold channels are used for induced extrusion to form the specified texture structure, and the assembly is not adhered after cooling, which is convenient for subsequent stretching and molding; S3: dynamic casting and speed and temperature regulation: cast the extruded melt onto the cooling roller, control the cooling roller temperature between 40-70℃; at the same time, start the cooling device, blow dry air at room temperature to the film surface through the blowing device, the wind speed is 2 m / s, to ensure the stable formation of the texture on the film surface; S4: programmed solidification and texture setting: the film after casting enters the programmed solidification module, is pulled under a set gradient temperature reduction path and constant tension, specifically includes three temperature reduction zones: the first stage is 80 DEG C, the second stage is 50 DEG C, and the third stage is room temperature, in the process, the film passes through the modular secondary shaping, so that it completes the final crystallization and solidifies the texture structure.

7. The method of claim 6, wherein, In step S2, the different feeders inject different set color combinations, wherein the proportion of each color is controlled between 1-5% to ensure the diversity and color uniformity of the final texture.

8. The method of claim 6, wherein the method further comprises, In step S2, the temperature of each section of the extruder is controlled between 160-200 DEG C, and the screw rotation speed is set to 300 rpm, in the process, different set color combinations are injected through multiple feeders, the proportion of color master batches in each feeder is controlled between 1-5%, and different mold flow channels are induced to form the set texture structure, and after cooling, the components are not adhered, facilitating subsequent stretching and molding.

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