Coating method of TPU material film

Abstract

The invention discloses a TPU (thermoplastic polyurethane) material film coating method which comprises the following steps: proportioning raw materials according to a certain proportion, grouping the raw materials according to a certain sequence for later use, kneading the raw materials by a kneading machine, plasticizing the raw materials, feeding the plasticized raw materials to a calender, and preparing the material by using a calendering manufacturing method. According to the invention, a better shearing effect is realized by controlling the rotating speed of a screw rod during cutting and coiling, and the rotating speed of the screw rod is limited in a certain range when a finished film is sheared and the conveyed screw rod is limited in a certain diameter range, so that the finished film can be sheared in a certain range. By means of the film shearing device, a film material can have a better shearing effect, unnecessary damage to a film during shearing is avoided, and unnecessary loss in the production process is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of material film coating, in particular to a coating method of a TPU material film. Background Art

[0002] TPU, short for thermoplastic polyurethane elastomer, is also called PU thermoplastic. It is a linear block copolymer composed of oligomer polyol soft segments and diisocyanate-chain extender hard segments. TPU film is a film made from TPU granules through special processes such as calendering, casting, film blowing, and coating. TPU film is an important application form of TPU material.

[0003] Cushioning packaging has become an indispensable component in the consumption and circulation of goods. High-quality packaging materials can improve the safety of goods and reduce the loss of goods during the circulation of goods. If the packaging method is inappropriate, precious electronic products such as tablets will cause damage to the products during the logistics process. It is very important to choose a packaging material suitable for the transportation of electronic products. In the past, packaging materials were mostly plastic foam, pearl cotton, waste newspapers and cushioning air bags. Among them, plastic foam and pearl cotton were the most commonly used packaging materials in the logistics and transportation of electronic products by e-commerce in the past. However, with the continuous improvement of consumers' environmental awareness, these materials have gradually faded out of people's vision. The new reinforced plastic elastomer protective film (TPU) is sliced ​​and attached to the inner surface of the carton. When used, the electronic products are placed between the protective film surface and the carton, and then the folded carton is formed to form a square box, thereby effectively protecting it. The reinforced plastic elastomer protective film (TPU) has excellent high tension, high tensile force, toughness and aging resistance. It is a mature, fashionable and environmentally friendly material.

[0004] However, based on the effect requirements, the TPU material film that forms a glossy film by itself needs to be made into a matte film. In order to make a matte film, the technology generally used is film layer composite or material coating. Therefore, the effect of a matte film can be achieved by covering the water-based polyurethane material on the TPU film, which involves the coating process of the material. It is not suitable to directly apply the existing coating process to the water-based polyurethane to the TPU material. First, there is a phenomenon of missing coating, which cannot be fully covered, resulting in quality problems; in addition, the production process requires drying treatment, which will cause curling on both sides. After winding, the two sides are thick and the middle is thin, and it cannot be wound neatly, and the loss is too high.

[0005] As disclosed in Chinese patent CN112642677A, a coating method of TPU material film is proposed. Through the setting of TPU material film, it is in surface contact with the coating roller to ensure the thick coating of waterborne polyurethane (waterborne polyurethane is applied by the coating roller) and the coating is evenly applied. Specifically, it means that the TPU material film is in contact with the coating roller over a large area. Specifically, the contact area with the coating roller can be increased by adjusting the lead-out orientation of the TPU material film. Specifically, since the lead-out of the TPU material film requires a guide roller, and the guide roller tensions the TPU material film, the TPU material film can be staggered with the coating roller to make the TPU material film have a large area of ​​contact with the coating roller. The size of the specific area is based on the degree of staggering between the two. In order to ensure that the TPU material film as the substrate film will not curl, a TPU material film with a thickness greater than 0.05 mm is used. At the same time, the composite film is cut by a cutting mechanism before winding to avoid curling.

[0006] However, during the shearing process of the TPU material film, the rotation speed of the roller or screw used for shearing and conveying also needs to be limited within a certain range. Otherwise, it is easy for the material film to break due to excessively high rotation speed or to crack due to too long residence time of the material film due to too low rotation speed during cutting.

[0007] For this reason, we urgently need to provide a coating method for a TPU material film. Summary of the invention

[0008] In view of the deficiencies in the prior art, the present invention provides a coating method for a TPU material film, which has the advantages of being able to control the rotation speed of a conveying roller or a screw during shearing to better shear the material film, without damaging the produced material film and causing unnecessary losses. The method solves the problem that during the shearing process of the TPU material film, the rotation speed of the roller or screw used for shearing and conveying also needs to be limited to a certain range, otherwise it is easy for the material film to break due to excessively high rotation speed during cutting, or the material film to crack due to excessively low rotation speed causing the material film to stay for too long and then crack.

[0009] In order to achieve the above purpose of better shearing the material film by controlling the rotation speed of the conveying roller or the screw during shearing, without damaging the produced material film and causing unnecessary losses, the present invention provides the following technical solutions: 1. A coating method of a TPU material film, comprising the following steps: S1: Ingredient preparation: Accurately weigh the resin and various additives according to the formula ratio. After weighing the raw materials in the required formula ratio, place all the raw materials in a container in order for later use.

[0010] S2: Kneading: Add the ingredients into the kneading machine in a predetermined order and mix them thoroughly to ensure that the components are evenly dispersed and infiltrated. Use the kneading machine to fully mix all the raw materials to make the mixing between all the raw materials more uniform. After mixing evenly, the mixed materials need to be dried under certain temperature conditions.

[0011] S3: Plasticization: Use an internal mixer, high-speed kneader or extruder to heat the mixture to the viscosity flow temperature. Through the strong shearing action of the plasticizing machine, the components are fully sheared, mixed, infiltrated and melted with each other to achieve uniform mixing of the raw materials, uniform temperature and air, and uniform viscosity.

[0012] S4: Feeding: A roller press or an extruder can be used to feed the plasticized material to the calender through a transfer device, and the plasticized raw material is further plasticized.

[0013] S5: Calendering: Use a calender to squeeze the plastic into a film or sheet of a predetermined size within a preset temperature range and a predetermined speed.

[0014] S6: Detachment: The film or sheet is separated from the calendering roller by the action of the detachment roller. Before the calendering roller is used, the surface of the calendering roller must be protected from adhesion to prevent the produced film from adhering to the surface of the calendering roller and becoming difficult to detach.

[0015] S7: Embossing: The embossing roller and the rubber roller work together to give the product surface a certain pattern.

[0016] S8: Cooling: After the film or sheet is formed, it passes through several groups of cooling rollers and is cooled for a certain period of time to ensure the cooling and forming of the film.

[0017] S9: Conveying: The shaped products are conveyed to the next process in a relaxed state through the conveyor belt.

[0018] S10: Winding and cutting: By controlling the rotation speed of the screw to maintain a relatively stable rate, the formed TPU material film is sheared, and then it is wound at the same rate through the coiling device, and then the finished product is stored.

[0019] Preferably, when the raw materials are mixed in S2, they must be added in accordance with the proportions and order of the ingredients prepared in advance, and after ensuring that the raw materials are mixed evenly, they are dried at a temperature between 80° C. and 100° C. for 2 to 4 hours.

[0020] Preferably, during the plasticization in S3, the mixed and dried raw materials are put into an extruder and plasticized in a temperature range of 180° C. to 210° C. After plasticization, the plasticized raw materials are extruded by the extruder and transferred to a calender for calendering by a transport transfer device.

[0021] Preferably, when the S5-S6 is taken away by a take-away roller after calendering, the surface of the take-away roller should be properly treated to prevent adhesion, and a chrome-plated screw is preferably used for the take-away.

[0022] Preferably, during cooling in S8, the film material is cooled and formed within a temperature range of 20° C. to 40° C.

[0023] Preferably, when cutting and winding the finished film, the S10 controls the rotation speed of the screw to be between 20 rpms and 60 rpms, and the diameter of the screw is selected to be between 25 and 30.

[0024] Compared with the prior art, the present invention provides a coating method of a TPU material film, which has the following beneficial effects: 1. The coating method of the TPU material film can better achieve a better shearing effect on the film material by setting the diameter of the conveying screw to be within a certain range when the finished film is sheared, and limiting the rotation speed of the screw to be within a certain range, so as to avoid unnecessary damage to the film during shearing and avoid unnecessary losses in the production process.

[0025] 2. The coating method of the TPU material film can better plasticize the raw materials by limiting the plasticizing temperature during the production and processing, and at the same time, the surface material of the calendering conveying screw is treated with anti-adhesion, so that the film will not be damaged by curling due to the adhesion of the material during production and after shearing. Implementation

[0026] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example

[0027] A coating method for a TPU material film comprises the following steps: S1: Ingredient preparation: Accurately weigh the resin and various additives according to the formula ratio. After weighing the raw materials in the required formula ratio, place all the raw materials in a container in order for later use.

[0028] S2: Kneading: Add the ingredients into the kneading machine in a predetermined order and mix them thoroughly to ensure that the ingredients are evenly dispersed and infiltrated. Use the kneading machine to fully mix all the raw materials to make the mixing between all the raw materials more uniform. After mixing evenly, the mixed material needs to be dried at a temperature of 90°C for 3 hours.

[0029] S3: Plasticization: Use an internal mixer, high-speed kneader or extruder to heat the mixture to 200°C to the viscosity flow temperature. Through the strong shearing action of the plasticizing machine, the components are fully sheared, mixed, infiltrated and melted with each other to achieve uniform mixing of the raw materials, uniform temperature and air, and uniform viscosity.

[0030] S4: Feeding: A roller press or an extruder can be used to feed the plasticized material to the calender through a transfer device, and the plasticized raw material is further plasticized.

[0031] S5: Calendering: Use a calender to squeeze the plastic into a film or sheet of a predetermined size within a preset temperature range and a predetermined speed.

[0032] S6: Detachment: The film or sheet is separated from the calendering roller by the action of the detachment roller. Before the calendering roller is used, the surface of the calendering roller must be protected from adhesion to prevent the produced film from adhering to the surface of the calendering roller and becoming difficult to detach. Use a chrome-plated screw for detachment.

[0033] S7: Embossing: The embossing roller and the rubber roller work together to give the product surface a certain pattern.

[0034] S8: Cooling: After the film or sheet is formed, it passes through several groups of cooling rollers and is cooled at a temperature of 30°C to ensure the cooling and forming of the film.

[0035] S9: Conveying: The shaped products are conveyed to the next process in a relaxed state through the conveyor belt.

[0036] S10: Winding and cutting: The formed TPU material film is sheared by controlling the rotation speed of the screw with a diameter of 27 to maintain at 40rpms, and then it is wound at the same speed through the coiling device, and then the finished product is stored. Example

[0037] A coating method for a TPU material film comprises the following steps: S1: Ingredient preparation: Accurately weigh the resin and various additives according to the formula ratio. After weighing the raw materials in the required formula ratio, place all the raw materials in a container in order for later use.

[0038] S2: Kneading: Add the ingredients to the kneading machine in a predetermined order and mix them thoroughly to ensure that the components are evenly dispersed and infiltrated. Use the kneading machine to fully mix all the raw materials to make the mixing between all the raw materials more uniform. After mixing evenly, the mixed material needs to be dried at a temperature of 60°C for 2 hours.

[0039] S3: Plasticization: Use an internal mixer, high-speed kneader or extruder to heat the mixture to 180°C to the viscosity flow temperature. Through the strong shearing action of the plasticizing machine, the components are fully sheared, mixed, infiltrated and melted with each other to achieve uniform mixing of the raw materials, uniform temperature and air, and uniform viscosity.

[0040] S4: Feeding: A roller press or an extruder can be used to feed the plasticized material to the calender through a transfer device, and the plasticized raw material is further plasticized.

[0041] S5: Calendering: Use a calender to squeeze the plastic into a film or sheet of a predetermined size within a preset temperature range and a predetermined speed.

[0042] S6: Detachment: The film or sheet is separated from the calendering roller by the action of the detachment roller. Before the calendering roller is used, the surface of the calendering roller must be protected from adhesion to prevent the produced film from adhering to the surface of the calendering roller and becoming difficult to detach. Use a chrome-plated screw for detachment.

[0043] S7: Embossing: The embossing roller and the rubber roller work together to give the product surface a certain pattern.

[0044] S8: Cooling: After the film or sheet is formed, it passes through several groups of cooling rollers and is cooled at a temperature of 20°C to ensure the cooling and forming of the film.

[0045] S9: Conveying: The shaped products are conveyed to the next process in a relaxed state through the conveyor belt.

[0046] S10: Winding and cutting: The formed TPU material film is sheared by controlling the rotation speed of the screw with a diameter of 27 to maintain at 20rpms, and then the film is wound at the same speed through the coiling device, and the finished product is stored. Example

[0047] A coating method for a TPU material film comprises the following steps: S1: Ingredient preparation: Accurately weigh the resin and various additives according to the formula ratio. After weighing the raw materials in the required formula ratio, place all the raw materials in a container in order for later use.

[0048] S2: Kneading: Add the ingredients to the kneading machine in a predetermined order and mix them thoroughly to ensure that the ingredients are evenly dispersed and infiltrated. Use the kneading machine to fully mix all the raw materials to make the mixing between all the raw materials more uniform. After mixing evenly, the mixed material needs to be dried at a temperature of 120°C for 4 hours.

[0049] S3: Plasticization: Use an internal mixer, high-speed kneader or extruder to heat the mixture to 180°C to the viscosity flow temperature. Through the strong shearing action of the plasticizing machine, the components are fully sheared, mixed, infiltrated and melted with each other to achieve uniform mixing of the raw materials, uniform temperature and air, and uniform viscosity.

[0050] S4: Feeding: A roller press or an extruder can be used to feed the plasticized material to the calender through a transfer device, and the plasticized raw material is further plasticized.

[0051] S5: Calendering: Use a calender to squeeze the plastic into a film or sheet of a predetermined size within a preset temperature range and a predetermined speed.

[0052] S6: Detachment: The film or sheet is separated from the calendering roller by the action of the detachment roller. Before the calendering roller is used, the surface of the calendering roller must be protected from adhesion to prevent the produced film from adhering to the surface of the calendering roller and becoming difficult to detach. Use a chrome-plated screw for detachment.

[0053] S7: Embossing: The embossing roller and the rubber roller work together to give the product surface a certain pattern.

[0054] S8: Cooling: After the film or sheet is formed, it passes through several groups of cooling rollers and is cooled at a temperature of 40°C to ensure the cooling and forming of the film.

[0055] S9: Conveying: The shaped products are conveyed to the next process in a relaxed state through the conveyor belt.

[0056] S10: Winding and cutting: The formed TPU material film is sheared by controlling the rotation speed of the screw with a diameter of 27 to maintain at 60rpms, and then the film is wound at the same speed through the coiling device, and the finished product is stored.

[0057] In summary: Comparing Example 1, Example 2 and Example 3, when the raw materials are dried, the drying degree of drying for 3 hours at a drying temperature of 90°C is best for subsequent work effects, and when plasticizing, the plasticizing effect is best when the temperature zone is maintained at around 200°C, and when cooling and forming, the cooling forming effect is best when the cooling temperature is 30°C, and when the material is cut and coiled, the screw speed with a diameter of 27 is adjusted to 40rpms and maintained at this speed, and the shearing effect of the film material is best when the screw is conveyed using a chrome-plated screw, so Example 1 is the best embodiment of this application.

[0058] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A coating method for a TPU material film, characterized in that: The following steps are involved: S1: Ingredient preparation: accurately weigh the resin and various additives according to the formula ratio. After weighing the raw materials of the required formula ratio, place all the raw materials in the container in groups according to the order for later use; S2: Kneading: Add the ingredients to the kneading machine in a predetermined order and mix them thoroughly to ensure that the ingredients are evenly dispersed and infiltrated. Use the kneading machine to fully mix all the raw materials to make the mixing between all the raw materials more uniform. After the mixing is uniform, the mixed materials need to be dried under certain temperature conditions; S3: Plasticization: Use internal mixer, high-speed kneader or extruder to heat the mixture to the viscosity flow temperature. Through the strong shearing action of the plasticizing machine, the components are fully sheared, mixed, infiltrated and melted to achieve uniform mixing of raw materials, uniform temperature and air, and uniform viscosity; S4: Feeding: A roller press or an extruder can be used to feed the plasticized material to the calender through a transfer device, and the plasticized raw material is further plasticized at the same time; S5: Calendering: Using a calender, the plastic is squeezed into a film or sheet of a predetermined size within a preset temperature range and a predetermined speed; S6: Detachment: The film or sheet is separated from the calendering roller by the action of the detachment roller. Before the calendering roller is used, the surface of the calendering roller must be protected from adhesion to prevent the produced film from adhering to the surface of the calendering roller and becoming difficult to detach. 2.S7: Embossing: The embossing roller and the rubber roller work together to give the product surface a certain pattern; S8: Cooling: After the film or sheet is formed, it passes through several groups of cooling rollers and is cooled for a certain period of time to ensure the cooling and forming of the film; S9: Conveying: The shaped products are conveyed to the next process in a relaxed state through the conveyor belt; S10: Winding and cutting: By controlling the rotation speed of the screw to maintain a relatively stable rate, the formed TPU material film is sheared, and then it is wound at the same rate through the coiling device, and then the finished product is stored.

3. The coating method of a TPU material film according to claim 1, characterized in that: When the raw materials are mixed in S2, they must be added according to the proportions and order of the ingredients prepared in advance, and after ensuring that the raw materials are mixed evenly, they are dried at 60° C. to 120° C. for 2 to 4 hours.

4. The coating method of a TPU material film according to claim 1, characterized in that: During the plasticization in S3, the mixed and dried raw materials are put into an extruder and plasticized in a temperature range of 180° C. to 210° C. After plasticization, the plasticized raw materials are extruded by the extruder and transferred to a calender for calendering by a transport transfer device.

5. The coating method of a TPU material film according to claim 1, characterized in that: When the S5-S6 is taken away by a take-away roller after calendering, the surface of the take-away roller should be properly protected from adhesion, and a chrome-plated screw is preferably used for the take-away.

6. The coating method of a TPU material film according to claim 1, characterized in that: During cooling in S8, the film material is cooled and formed within a temperature range of 20° C. to 40° C.

7. The coating method of a TPU material film according to claim 1, characterized in that: When the S10 is cutting and winding the finished film, the rotation speed of the screw is controlled between 20 rpms and 60 rpms, and the diameter of the screw is selected between 25 and 30.