Injection molding in the medical industry is also a branch of the whole injection molding field. After years of development, injection molding in the traditional Chinese medicine industry also has its unique processes and requirements. In the process of plastic injection molding, how to solve the problem of crazing and bubbles in injection molded products? How to improve the process if the product is not filled enough?

How to solve the craze and bubble of injection molded products?

Plastic is disturbed by gas in the filling process, and silver stripes or tiny bubbles often appear on the surface of products or bubbles form in the thick wall of products. The main source of these gases is that the raw materials contain too much water or volatile substances or lubricants, or the material temperature is too high, the plastic is heated for a long time, and degradation occurs, resulting in decomposition gas.

1. Equipment

The nozzle hole is too small, the materials salivate or wire drawing at the nozzle, the machine barrel or nozzle has obstacles or burrs, and the friction heat is generated when the high-speed material flow passes, causing the material to decompose.

2. Mold

(1) Due to design defects, such as poor gate position, too small gate, asymmetric gate layout of multi gate parts, small runner, unreasonable mold cooling system, too large mold temperature difference, etc., the flow of molten material in the mold cavity is discontinuous, blocking the air channel.

(2) The mold parting surface is lack of necessary exhaust channels, or the exhaust channels are insufficient, blocked, and in a poor position. There is no processing gap such as inserts and thimbles to exhaust, resulting in the air in the cavity cannot leave at the same time when the plastic enters.

(3) The surface roughness of the mold is poor, and the friction resistance is large, causing local hot spots and decomposing the passing plastic.