TPU extrusion casting film testing machine

Guangzhou POTOP Co., Ltd. customized a small single screw casting film machine for Thermoplastic Polyurethane (TPU) materials. The thin film products produced by this equipment have uniform thickness, no black spots, crystal dots, or wrinkles. The purpose of a small single screw extrusion casting film machine is to make casting film samples, thereby adjusting material formulas, process research, parameter optimization, etc.

POTOP customizes the required casting machine based on TPU material properties, product requirements (width, accuracy, etc.), and product processing and forming requirements.

Equipment features:

Pu Tong not only achieves precise and controllable screw speed in the single screw extruder host, but also multi zone temperature control in the barrel, high precision and controllability, and is designed on the casting auxiliary machine

Has unique design advantages.

1. Power rollers such as casting roller, back pressure roller, traction roller, and winding roller are all driven by servo motors, with precise roller speed control and good synchronization performance.

2. Using a slider device to improve the balance of the equipment and facilitate left and right movement.

3. The casting roller and back pressure roller are precisely adjusted by the motor and screw for lifting, and the appropriate casting forming process can be adjusted according to the melt strength of different formula materials.

4. According to the material process, roller temperature control instruments (mold temperature machine, water machine, or integrated cold and hot machine) can be selected to achieve high precision of roller temperature control, ± 1 ℃

Technical parameter

Precautions for TPU material extrusion processing:

1. TPU belongs to the category of hygroscopic materials, which quickly absorb moisture when placed in the air. Especially polyethers are more hygroscopic than polyester, so good sealing must be ensured

Sealing status. Materials are more prone to moisture absorption in hot conditions, so the remaining materials should be quickly sealed after packaging. Control the moisture content below 0.02% during processing. Therefore, drying is necessary before application, and it is recommended to use a circulating air dryer or dehumidification dryer to dry TPU. According to the material hardness, the drying temperature is 80-110 ℃ and the drying time is about 3 hours. If color powder or masterbatch is used for dyeing, it must be thoroughly mixed with TPU natural color particles and dried together.

Note： that if the ratio of added colorants and additives is not appropriate, it can lead to unsatisfactory TPU homogenization effect and irregular shape during the extrusion process.

2. TPU is sensitive to shear, so it is necessary to control the screw speed well. If the speed is too high, it can easily lead to decomposition, but if it is too low, it can easily lead to cracking due to long residence time, usually at a speed of 20-60rpms. The length to diameter ratio of the screw is around 25-30, and the compression ratio is 2-3.

3. Different types and models of TPU materials have different melting points and usage temperatures, and it is best to use more sections for controlling the barrel temperature (such as 4)

Temperature control in sections 1-5 requires precise temperature adjustment. The rationality of mechanical design is closely related to whether the TPU material extrusion process will produce adverse phenomena such as surface stripes, roughness, and fisheye formation.