What are the setting principles of the mold temperature control system in the injection mold processing plant?

The mold of the injection mold processing plant should be equipped with a mold temperature control system of the mold cooling or heating device according to the different plastic varieties to be molded.
①Injection mold processing plants are used for plastics with low viscosity and good flow, such as polystyrene (PS), polyvinyl chloride (PVC), polyethylene (PE), polyamide (also known as nylon PA) and polypropylene (PP), etc. For plastics with low viscosity, it is necessary to install a cooling device on the mold. Generally, warm water is used for cooling; in order to shorten the time of cold hardening, cold (room temperature) water cooling can also be used.
②For plastics with high viscosity and poor flow, such as polycarbonate (PC), polysulfone (PSF), polyoxymethylene (POM), polyphenylene ether (PPO) and fluoroplastics, in order to improve the fluidity, The mold needs to be heated. For plastics with good thermal performance and fluidity, but when molding thick-walled injection parts (wall thickness above 20mm), a heating device must also be added.
③For thermosetting plastics, the working temperature of the mold should be 150~200℃, so the mold must be heated.
④Crystalline and amorphous plastics. Since crystalline plastics have the characteristics of more heat during cooling, fast cooling rate, low crystallinity, small shrinkage and high transparency, they need to be fully cooled during molding. The crystallinity is related to the wall thickness of the injection molded parts. When the wall thickness of the injection molded parts is small, the cooling is fast, the crystallinity is low, the shrinkage is small and the transparency is high; on the contrary, when the wall thickness of the injection molded parts is large, the cooling is slow, the crystallinity is high, the shrinkage is large, and the physical properties and mechanical properties. Well, crystalline plastics must control the mold temperature as required. Generally, crystalline plastics are opaque or translucent, such as polyamide (PA). Amorphous plastics are transparent, such as plexiglass. But there are exceptions, such as crystalline plastic poly. Methylpentene is highly transparent, while the non-crystalline plastic ABS is opaque.
⑤ The injection mold processing factory needs to use a deepened sprue sleeve and a hot runner to increase the temperature of the melt filling to improve the fluidity of the plastic melt for a mold with a long main runner.
⑥ For injection molded parts with long processes and thick walls or large molding area, in order to ensure sufficient filling of the plastic melt, a heating device should be considered. For thin-walled injection molded parts, the cooling device can be relied on the heat dissipation of the mold itself without the need for a cooling device.

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