TPE raw material is an environmentally friendly, non-toxic and safe product, with a wide range of hardness (0-95A), excellent colorability, soft touch, weather resistance, fatigue resistance and heat resistance, excellent processing performance, no need Vulcanized, and can be recycled to reduce costs, therefore, TPE raw materials are widely used in injection molding, extrusion, blow molding, molding and other processing. So do you know what the requirements for the injection molding process of TPE raw materials are? Let’s see the follows.
TPE raw material injection molding process requirements:
1. Dry the TPE raw material.
In general, if there are strict requirements on the surface of TPE products, the TPE raw materials must be dried before injection molding. Because in injection molding production, TPE raw materials generally contain varying degrees of moisture and many other volatile low-molecular-weight polymers. Therefore, the water content of TPE raw materials must be measured first, and those with too high water content must be dried. The general drying method is to use a drying dish to dry at 60℃ ~ 80℃ for 2 hours. Another method is to use a drying chamber hopper, which can continuously supply dry hot material to the injection molding machine, which is beneficial to simplifying the operation, maintaining cleanliness, improving quality, and increasing injection rate.
2. Try to avoid high temperature injection molding.
Under the premise of ensuring the quality of plasticization, the extrusion temperature should be reduced as much as possible, and the injection pressure and screw speed should be increased to reduce the viscosity of the melt and improve the fluidity.
3. Set the appropriate TPE injection temperature.
In the process of injection molding TPE raw materials, the general temperature setting range of each area is: barrel 160℃ to 210℃, nozzle 180℃ to 230℃. The temperature of the mold should be higher than the condensation temperature of the injection molding area, so as to avoid the stripes on the surface of the product and the defects of the injection molding cold glue, so the mold temperature should be designed to be between 30℃ and 40℃.
4. The injection speed should be from slow to fast.
If it is several levels of injection, the speed is from slow to fast. Therefore, the gas in the mold is easily discharged. If the inside of the product is wrapped in gas (expanding inside), or if there are dents, the trick is ineffective, this method can be adjusted. Moderate injection speeds should be used in SBS systems. In SEBS system, a higher injection speed should be used. If the mold has a sufficient exhaust system, even high-speed injection does not have to worry about trapped air.
5. Pay attention to control the processing temperature.
The processing temperature of TPE raw materials is about 200 degrees, and TPE will not absorb moisture in the air during storage, and generally no drying process is required. Bake at high temperature for 2 to 4 hours. TPE encapsulated ABS, AS, PS, PC, PP, PA and other materials need to be pre-baked and baked at 80 degrees for 2 to 4 hours.
In summary, it is the TPE raw material injection molding process requirements. TPE raw material is a widely used thermoplastic elastomer material, which can be injection molded alone or thermally bonded with PP, PE, ABS, PC, PMMA, PBT and other materials for secondary injection molding, and the material can be recycled. Safe and environmentally friendly, it has already become a new generation of popular rubber and plastic materials.
Post time: Jun-15-2022