A TPU composite film production device and use method thereof

Abstract

The invention relates to a TPU composite film production device, comprising a plurality of TPU extrusion production lines arranged in parallel, each TPU extrusion production line comprising a TPU extruder, an automatic screen changer, a high-precision metering pump, a secondary filter and a distributor which are sequentially connected through a flow channel pipeline, the distributor of each TPU extrusion production line is commonly connected to a die head, and a casting or calendering device is arranged after the die head; the invention filters TPU slurry twice, which is not only beneficial to the removal of impurities of the TPU slurry, but also beneficial to the further mixing of the TPU slurry, and at the same time, the TPU slurry is finally sheared, dispersed and mixed before entering the die head through a shear filter, so that the TPU slurry is more stable, and the surface flatness and smoothness of the composite film after final film formation are higher, the surface pattern and local granularity are not easy to appear, and the product quality is higher.

Description

Technical Field

[0001] The invention belongs to the technical field of mechanical equipment, and specifically relates to a TPU composite film production device and a use method thereof. Background Art

[0002] Thermoplastic polyurethane elastomer (TPU) is a non-toxic, harmless, environmentally friendly material that can be recycled and reused repeatedly, can be naturally degraded, and can partially replace non-environmentally friendly materials such as PVC. Therefore, it has become a popular material at present and is widely used in various aspects of people's lives. At present, it is widely used in daily necessities, sporting goods, toys, decorative materials and other fields. TPU film also meets the environmental protection requirements of more and more fields. However, the existing single-layer TPU film has a relatively single performance. Its elasticity, toughness, wear resistance, weather resistance and other properties are difficult to meet the requirements of some customers. It is also prone to yellowing, hydrolysis and other series of problems. Therefore, composite TPU film materials are more popular in the market with their good comprehensive performance. In addition, the current composite TPU film products generally have problems such as uneven surface (sometimes it appears to be actually flat, but the surface looks grainy or uneven), and local granularity (some small particles are not filtered).

[0003] The invention patent with the patent number of 201310061293X and the name of "Synchronous Double-sided High-peel TPU Composite Cloth Extrusion Coating Device" discloses a synchronous double-sided high-peel TPU composite cloth extrusion coating device, including a symmetrical double-layer composite die head and a TPU extrusion mechanism, the symmetrical double-layer composite die head includes two sub-molds symmetrical to each other, each sub-mold is provided with a feed channel connected to the composite channel, the TPU extrusion mechanism includes two sets, and each set of TPU extrusion mechanism includes a TPU extruder and a melt pump connected to the discharge end of the TPU extruder, and the discharge ends of the melt pumps of the two sets of TPU extrusion mechanisms are respectively connected to the feed channels of the above two sub-molds. The invention uses a dual system to coat the TPU melt on both sides of the base cloth, which is also a common method for preparing TPU composite films. There is also a great market demand for TPU composite films without base fabrics. TPU composite films without base fabrics have good anti-peel properties, but they are relatively more prone to problems such as uneven surface and local granularity.

[0004] In view of this, it is necessary to propose a TPU composite film production equipment with better surface treatment. Summary of the invention

[0005] The purpose of the present invention is to provide a TPU composite film production device with better product surface effect and more stable performance and a use method thereof.

[0006] In order to solve the above technical problems, the present invention discloses a TPU composite film production equipment, comprising a plurality of TPU extrusion production lines arranged in parallel, each TPU extrusion production line comprises a TPU extruder, an automatic screen changer, a high-precision metering pump, a secondary filter and a distributor which are sequentially connected through a flow channel pipeline, and the distributor of each TPU extrusion production line is commonly connected to a die head, and a casting or calendering device is arranged behind the die head;

[0007] The TPU extruder includes a screw barrel for melting TPU pellets and extruding slurry and a motor for driving the screw barrel, and a feed port is provided on the screw barrel; the automatic screen changer is used to perform a primary filtration on the slurry sent out by the TPU extruder to remove most of the impurities, and filter the slurry again through a secondary filter; the metering pump is used to control the slurry supply to achieve control of the casting thickness of the TPU single-layer film, and the distributor is used to evenly distribute the slurry on the die head.

[0008] Preferably, there are two TPU extrusion production lines.

[0009] Preferably, the die is a T-die.

[0010] Preferably, the filter screen used in the automatic screen changer is 50-100 mesh, and the filter screen used in the secondary filter is 100-300 mesh.

[0011] Preferably, a main flow channel and a plurality of branch flow channels are provided in the distributor, and a shear filter is provided at the slurry outlet of each branch flow channel.

[0012] Preferably, the shear filter comprises a fixed frame and a first filter and a second filter fixed in parallel in the fixed frame.

[0013] Preferably, the first filter disc is uniformly processed with multiple rows of short slits, and the second filter disc is uniformly processed with multiple long slits, and the arrangement direction of the long slits is parallel to the discharge direction of the die head.

[0014] Preferably, the short slits and the long slits are arranged vertically and staggered, the projection of the long slits on the first filter plate falls between two adjacent rows of short slits, and the length of the short slit is not greater than the distance between two adjacent long slits.

[0015] Preferably, the short slits have a width of 0.06-0.12 mm, the long slits have a width of 0.04-0.10 mm, and the total area of ​​the long slits is not greater than the total area of ​​the short slits.

[0016] A method for manufacturing a TPU composite film using a TPU composite film production device, characterized in that it comprises the following steps:

[0017] S1. Different TPU pellets are put into two screw barrels respectively, and the TPU pellets are heated and melted into slurry in the screw barrel;

[0018] S2. After the slurry is initially filtered by the automatic screen changer, it is mixed by the metering pump and then filtered again by the filter. Then it enters the distributor. After being distributed by the distributor, the slurry enters the die head and is co-extruded;

[0019] S3. The slurry extruded from the die is cast by a casting roller to form a double-layer TPU film;

[0020] S4. The double-layer TPU film is cooled and formed and then rolled up.

[0021] The TPU composite film production equipment of the present invention has the following beneficial effects:

[0022] Filtering the TPU slurry twice is not only beneficial to the removal of impurities in the TPU slurry, but also to the further mixing of the TPU slurry. At the same time, the shear filter is used to perform the final shearing, dispersion and mixing of the TPU slurry before entering the die head, making the TPU slurry more stable. After the composite film is finally formed, the surface flatness is higher and the smoothness is better. It is not easy to have surface patterns and local granularity, and the product quality is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the structure of a TPU composite film production equipment.

[0024] Figure 2 for Figure 1 Schematic diagram of the structure of the TPU extrusion production line (TPU extruder is not shown).

[0025] Figure 3 for Figure 2 Schematic diagram of the side view of the structure of a single TPU extrusion production line.

[0026] Figure 4 A schematic diagram of the structure of a shear filter.

[0027] Figure 5 It is a schematic diagram of the structure of a first filter and a second filter.

[0028] The numbers in the figure are: 1-motor, 2-gearbox, 3-feed port, 4-screw barrel, 5-automatic screen changer, 6-high-precision metering pump, 7-flow channel pipeline, 8-secondary filter, 9-distributor, 10-die head, 11-shear filter, 12-first filter, 13-second filter, 14-long slit, 15-short slit. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below through examples so that those skilled in the art can implement the invention with reference to the description.

[0030] It should be understood that the terms such as “having”, “including” and “comprising” used herein do not exclude the existence or addition of one or more other elements or combinations thereof.

[0031] like Figure 1-3 As shown, a TPU composite film production equipment includes two TPU extrusion production lines arranged in parallel on a bracket, each TPU extrusion production line includes a TPU extruder, an automatic screen changer 5, a high-precision metering pump 6, a secondary filter 8 and a distributor 9 which are sequentially connected through a flow channel pipeline 7, and the distributor 9 of each TPU extrusion production line is commonly connected to a T-shaped die head 10, and a casting or calendering device and a subsequent cooling and winding device are arranged behind the die head 10;

[0032] The TPU extruder includes a screw barrel 4 for melting TPU pellets and extruding slurry and a motor 1 for driving the screw barrel 4. In this embodiment, a gearbox 2 is further provided between the motor 1 and the screw barrel 4 to cooperate with a high-precision metering pump 6 to accurately control the feeding speed;

[0033] The screw barrel 4 is provided with a feed port 3; the automatic screen changer 5 is used for primary filtering of the slurry sent out by the TPU extruder to remove most of the impurities, and the slurry is filtered again through the secondary filter 8. The double filtration is not only beneficial to the removal of impurities in the TPU slurry, but also beneficial to further mixing the TPU slurry. The automatic screen changer 5 can remove most of the impurities in the TPU slurry, and the high-precision metering pump can further remove or break up the impurities and uneven areas of the TPU slurry; the metering pump is used to control the slurry supply to achieve the control of the casting thickness of the TPU single-layer film, and the distributor 9 is used to evenly distribute the slurry on the die head 10.

[0034] The filter screen used in the automatic screen changer 5 is 50-100 mesh, and the filter screen used in the secondary filter 8 is 100-300 mesh. The smaller the mesh size of the filter screen, the better the filtering effect, but at the same time the greater the filtering resistance. In this embodiment, the filter screen used in the secondary filter 8 is a steel filter screen, which needs to be cleaned regularly.

[0035] like Figure 4-5 As shown, the distributor 9 is provided with a main channel and a plurality of branch channels, and a shear filter 11 is provided at the slurry outlet of each branch channel. The shape of the shear filter 11 is adapted to the shape of the slurry outlet of the branch channel.

[0036] The shear filter 11 includes a fixed frame and a first filter 12 and a second filter 13 fixed in parallel in the fixed frame. The first filter 12 is evenly processed with multiple rows of short slits 15, and the second filter 13 is evenly processed with multiple long slits 14, and the arrangement direction of the long slits 14 is parallel to the discharge direction of the die 10. The shear filter 11 further shears, disperses and mixes the TPU slurry before entering the die 10, so that the TPU, masterbatch, additives, fillers, etc. in the TPU slurry are mixed more evenly and in a more stable state, which is conducive to improving product quality.

[0037] The short slits 15 and the long slits 14 are arranged vertically and staggered, and the projection of the long slits 14 on the first filter plate 12 falls between two adjacent rows of short slits 15 (the long slits 14 are not directly opposite to the short slits 15, which can make the path of the slurry flowing out of the shear filter plate 11 longer, thereby improving the shear dispersion efficiency), and the length of the short slits 15 is not greater than the distance between the two adjacent long slits 14. Under this layout, when the slurry exits the short slits 15, it is sheared and dispersed by the short slits 15. After the slurry exits the short slits 15, it flows vertically toward the long slits 14 in the form of multiple flat slurries. The multiple flat slurries converge at the long slits 14 and are sheared and dispersed by the long slits 14 again. Since the arrangement direction of the long slits 14 is parallel to the discharge direction of the die head 10, the slurry enters the die head 10 in the form of multiple flat strands after exiting the long slits 14, which can pre-treat the arrangement of the slurry before entering the die head 10, and is conducive to uniform film formation.

[0038] The short slit 15 has a width of 0.06-0.12 mm, the long slit 14 has a width of 0.04-0.10 mm, and the total area of ​​the long slit 14 is smaller than the total area of ​​the short slit 15. The short slit 15 and the long slit 14 can further filter the slurry, and can also disperse and shear the slurry to make the slurry more uniform and stable. Even if there are still a small amount of impurities, the short slit 15 and the long slit 14 can sort out the orientation of the flaky or strip-shaped impurities, so that the flaky or strip-shaped impurities are more parallel to the surface of the TPU composite film, so that the surface of the TPU composite film is less likely to have a granular feel.

[0039] A method for manufacturing a TPU composite film using a TPU composite film production device, characterized in that it comprises the following steps:

[0040] S1. Different TPU pellets are put into two screw barrels 4, and the TPU pellets are heated and melted into slurry in the screw barrel 4;

[0041] S2. After the slurry is initially filtered by the automatic screen changer 5, it is mixed by the metering pump and then filtered again by the filter, and then enters the distributor 9. After the slurry is distributed by the distributor 9, it enters the die head 10 and is co-extruded;

[0042] S3. The slurry extruded from the die 10 is cast by a casting roller to form a double-layer TPU film;

[0043] S4. The double-layer TPU film is cooled and formed and then rolled up.

[0044] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the embodiments shown and described herein.

Claims

1. A TPU composite film production equipment, characterized in that: It includes multiple TPU extrusion production lines arranged in parallel, each TPU extrusion production line includes a TPU extruder, an automatic screen changer, a high-precision metering pump, a secondary filter and a distributor which are sequentially connected through a flow channel pipeline. The distributor of each TPU extrusion production line is commonly connected to a die head, and a casting or calendering device is arranged behind the die head; The TPU extruder includes a screw barrel for melting TPU pellets and extruding slurry and a motor for driving the screw barrel, and a feed port is provided on the screw barrel; the automatic screen changer is used to perform a primary filter on the slurry sent out by the TPU extruder to remove most of the impurities, and filter the slurry again through a secondary filter; the metering pump is used to control the slurry supply to achieve the control of the casting thickness of the TPU single-layer film, and the distributor is used to evenly distribute the slurry on the die head; A main channel and multiple branch channels are provided in the distributor, and a shear filter is provided at the slurry outlet of each branch channel; the shear filter comprises a fixed frame and a first filter plate and a second filter plate fixed in parallel in the fixed frame; the first filter plate is evenly processed with multiple rows of short slits, and the second filter plate is evenly processed with multiple long slits, and the arrangement direction of the long slits is parallel to the discharge direction of the die head; the short slits and the long slits are arranged vertically and staggered, and the projection of the long slits on the first filter plate falls between two adjacent rows of short slits, and the length of the short slit is not greater than the spacing between two adjacent long slits.

2. The TPU composite film production equipment according to claim 1, characterized in that: The number of the TPU extrusion production lines is two.

3. The TPU composite film production equipment according to claim 2, characterized in that: The die is a T-die.

4. The TPU composite film production equipment according to claim 1, characterized in that: The filter screen used in the automatic screen changer is 50-100 mesh, and the filter screen used in the secondary filter is 100-300 mesh.

5. The TPU composite film production equipment according to claim 1, characterized in that: The short slits have a width of 0.06-0.12 mm, the long slits have a width of 0.04-0.10 mm, and the total area of ​​the long slits is not greater than the total area of ​​the short slits.

6. A method for using the TPU composite film production equipment according to claim 2, characterized in that: The steps include: S1. Different TPU pellets are put into two screw barrels respectively, and the TPU pellets are heated and melted into slurry in the screw barrel; S2. After the slurry is initially filtered by the automatic screen changer, it is mixed by the metering pump and then filtered again by the filter. Then it enters the distributor. After being distributed by the distributor, the slurry enters the die head and is co-extruded; S3. The slurry extruded from the die is cast by a casting roller to form a double-layer TPU film; S4. The double-layer TPU film is cooled and formed and then rolled up.

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