Do you know how to do the coated sand gloss is not enough

Coated sand mainly adopts high quality selection of natural quartz sand as the original sand. Thermoplastic phenolic resin, urotropine and reinforcing agent as raw materials. According to the different technical requirements of users, the ratio is appropriately adjusted in terms of curing speed, film release, fluidity, collapsibility, casting surface finish, storage, etc. The following is about the reasons and solutions for the insufficient gloss of coated sand:

1. The surface of the mold (core) is loose: the core injection pressure is too high or too low; The mold does not exhaust smoothly; The mold runs sand due to the large gap between the box surfaces. Coated sand has poor fluidity or poor air permeability. Choose reasonable sand injection pressure to improve the exhaust system and prevent suffocation; use materials with small deformation as core boxes; choose coated sand with good fluidity and air permeability.

2. Coated sand has poor high temperature resistance, and some high temperature resistant additives can be added. This additive can be sintered at high temperature to make the casting smooth.

3. Shelling mold design is unreasonable, the core box temperature is not uniform, so that the low temperature part strength is low and shelling; coated sand melting point is low, curing speed is slow, thermal strength is low. Improve the mold structure, so that the temperature distribution is uniform; choose high melting point, fast curing speed, high thermal strength of the resin.

In fact, China's coated sand technology began in the mid-1950s and was once discontinued in the 1960 s. In the 1980 s, due to the rapid development of the automobile industry and the export of mechanical products, higher requirements were put forward for the quality of castings, thus promoting the rapid development of coated sand production and application technology. By the 21st century, the annual production and sales volume of China's coated sand industry has reached more than 900000 tons, which is widely used in the production of automobile cylinder blocks, cylinder heads, intake manifolds, various pipe fittings, pump bodies and other complex castings.

This article is finished by coated sand, the point of view of this article does not represent the point of view of this site.