First, the mold rusty reasons
1-1, Forming material decomposition products,such as chloride ions- decomposition from the PVC production process .
1-2, mold resurgence.
1-3, sweat on hand.
1-4, other foreign matters such as circulating water, steam and so on.
Second, the associated knowledge
2-1, The decomposition of the molding material products (gas, residue) is the most common corrosion of the mold. In order to prevent rust of the mold, the most widely used is to make chrome-plated treatment of mold cavity. However, chrome treatment can not tatally solve the problem, because the decomposition of the pin hole deep part of the corrosion. Where these places can not be plated.
2-2, when the mold is cooled below the rewet point, the moisture in the air resurfaces on the surface of the mold to produce water droplets, and rusting occurs.
Third, solve the problem
3-1, Short-term countermeasures; Fully dry the molding material and lower the barrel temperature to prevent material breakdown.
3-2, Long-term; the product material into decomposition products which have no corrosion on the mold material.
Fourth, due to differences in plastic materials
4-1, Easily decomposed materials, such as PVC, POM, EVA, PC and foam materials. Because decomposition products have a corrosive effect on the mold, the mold should be chrome-plated.
Five, reference matters
5-1, When the temporary stop molding, the mold cavity spray rust inhibitor, and then close the mold.
5-2, Mold long-term no use, the mold outside and activities should be coated by the butter .