Plastic material identification Judging thermoplastics and thermosets: All thermosets have no softening process when heated or burned, only become brittle and coked; All thermoplastics, which are heated or burned, undergo a soft melting process, but different plastics burn. The phenomenon is different. PP burns slowly, the upper end of the flame is yellow, the middle …
Gas-assisted injection molding is an innovative technology developed on the basis of traditional injection molding. . GIM (Gas-assisted injection molding) was adopted in production since 1980s. It is currently widely used in Europe and North America, Japan and South Korea, and many manufacturers in China have also adopted this new technology. The principle of gas-assisted …
There are many classification for plastic injection molds. According to the basic injection mold gating system, it can be divided into three types: Two-plate mold; Three-plate mold; Hot runner mold, also called runnerless mold. Other molds, such as side core pulling mechanism, core-unscrewing de-molding mechanism, are evolved from these three types of molds. Two-plate …
Hot runner system can be seen as an extension of injection molding machinery. The function of the hot runner system is to thermally insulated to send the thermoplastic melt to the plastic mold. The hot runner can be heated independently while it is thermally insulated in the injection mold, which can compensate for heat loss …
The Difference between insert molding and Double Color molding The so-called two-color injection molding refers to the molding method of injecting two kinds of plastics with different colors into the same mold. It can make the plastic parts with two different colors, and it can make the plastic parts show regular patterns or irregular patterns, …
Acrylic is also called polymethyl methacrylate (PMMA). Due to the defects , such as low surface hardness, easy scratching, low impact resistance and poor molding fluidity, the modification of PMMA appears alot. Such as copolymerization of methyl methacrylate with styrene and butadiene, mixing of PMMA with PC, etc. The flow of PMMA is worse than …
The problem of shrinkage of plastic injection parts (surface shrinkage and internal shrinkage) is due to the insufficient melt replenishment when the thick part is cooled. We often encounter these sink problems, no matter how to increase the pressure, increase the water lines numbers,and extend the time of the injection, the shrinkage problem is unsolvable. …
The plastic mold can be viewed as an exchanger that carries the heat of the hot melt away from the plastic mold by the circulating refrigerant. The role of the cooling system 1. Improve productivity 2. Ensure the effective of a mold In the whole cycle of thermoplastic injection molding, the mold cooling time accounts …
If the plastic parts are unevenly shrink-ed, the internal stress distribution will be uneven. If the stress exceeds the rigidity of the plastic part, the warpage and deformation of the plastic part will be found, which will affect the dimensional stability of the plastic part. But what is warpage? When internal stress (due to uneven …
The temperature of the injection mold has a great influence on the filling, solidification , production efficiency, and the shape and dimensional accuracy of the plastic parts. Each kind of plastic material has a reasonable mold temperature arrange, which makes the melt flow easily fill the cavity. If the mold temperature is reasonable, the shrinkage …