Views: 0 Author: Site Editor Publish Time: 2023-07-17 Origin: Site
Transparent plastic injection molding process is an advanced manufacturing method, widely used in various fields. Through mold making, plastic heating, filling pressure and other steps, high quality transparent plastic products can be efficiently produced.
1, PMMA process characteristics
PMMA viscosity is large, the fluidity is slightly poor, so it must be high material temperature, high injection pressure injection molding, in which the injection temperature influence is greater than the injection pressure, but the injection pressure increase, is conducive to improving the shrinkage of the product. The injection temperature range is wide, the melting temperature is 160℃, and the decomposition temperature is 270℃, so the material temperature adjustment range is wide, and the process is good. Therefore, the fluidity can be improved from the injection temperature. The impact is poor, the wear resistance is not good, the scratching is easy, and the cracking is easy, so the mold temperature should be increased and the condensation process improved to overcome these defects.
2, PC process characteristics
PC viscosity, high melt temperature, poor fluidity, so it must be injected at a higher temperature (270-320 ° C), relatively speaking, the material temperature adjustment range is narrow, the process is not as good as PMMA. The injection pressure has little effect on the fluidity, but because of the large viscosity, the injection pressure is still larger, and the corresponding pressure holding time should be as short as possible in order to prevent the internal stress.
The shrinkage rate is large and the size is stable, but the internal stress of the product is large and easy to crack, so it is appropriate to increase the temperature rather than pressure to improve the fluidity, and to reduce the possibility of cracking by increasing the mold temperature, improving the mold structure and post-processing. When the injection speed is low, the gate is prone to corrugation and other defects, the nozzle temperature should be controlled separately, the mold temperature should be high, and the flow path and gate resistance should be small.
3, PET process characteristics
PET molding temperature is high, and the material temperature adjustment range is narrow (260-300℃), but after melting, the flow is good, so the process is poor, and often in the nozzle to add anti-casting device. The mechanical strength and properties are not high after injection, and must be improved by stretching process and modification. Accurate control of mold temperature is to prevent warping. Deformation is an important factor, so it is recommended to use hot runner mold. Mold temperature should be high, otherwise it will cause poor surface luster and demoulding difficulties.
Transparent plastic products are widely used in various fields, including medical devices, electronic products, tableware, optical instruments and so on. In the future, with the continuous progress of science and technology and the constant change of market demand, transparent plastic injection molding process will continue to develop and innovate, intelligent and automated production, green environmental protection and sustainable development will be the focus of future development.