Plastic mold is a plastic processing mold. It is made of 45 steel, P20, 718 and other plastic mold steel. If it can analyze the failure mode and cause of plastic mold, it can better guide the development of mold steel, and improve plastic mold. the quality of.
There are many ways of plastic mold failure. One is the wear and corrosion of the cavity surface. When the plastic melt moves in the cavity under a certain pressure and the solidified plastic part comes out of the mold, it will mold the appearance of the mold. Forms friction and causes wear.
Secondly, reinforcing the resin filler in plastic guessing will also cause scouring, abrasion and corrosion to the appearance of the mold cavity. In a plastic processing, components containing chlorine, fluorine and other components are thermally decomposed to produce corrosive gases HCl and HF. These cross effects will cause damage to the coating or protective layer on the surface of the cavity, causing wear and corrosion.
The other is the failure of plastic deformation of plastic molds, which may be due to plastic deformation failure caused by compression and heat on the surface of the cavity of the plastic model, especially when small molds are operated on large-tonnage equipment, it is more prone to overload plastic deformation; Or the material used for the plastic mold lacks the strength and toughness of the material, and the deformation resistance is low; or there may be too thin a hardened layer on the surface of the cavity of the plastic mold, the lack of deformation resistance, or the softening of the phase change when the working temperature is higher than the tempering temperature Will cause damage to the appearance of the mold, such as depression, wrinkles, pits, corners and piles.
There is also a failure mode of plastic molds, which is cracking, especially the shape of plastic molds is chaotic, and there are many edges and corners, thin walls and other parts. The stress concentration in these parts will cause cracking. Structural stress, thermal stress caused by temperature difference, or lack of tempering, the remaining austenite is transformed into martensite at the application temperature, which causes part of the volume to expand and cause stress to occur inside the mold.
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