What are the design principles of injection molds?

Injection mold is an important method for plastic molding processing, and thermoplastic injection molding occupies a dominant position in the injection molding process. Now all kinds of disorganized injection molding structural parts, functional parts and precision parts for special purposes have been widely used in transportation, packaging, storage and transportation, communications, construction, home appliances, automobiles, electronics and aerospace. Indispensable important product.

Due to the chain-like structure, the direction of plastic shortening during processing is also related to the orientation and cooling shortening of polymer molecular chains under stress. The shortening in the direction of motion is greater than the shortening in the direction of the straight line. Plastic mold opening

Product shortening is also related to factors such as product shape, gate, thermal expansion and contraction, temperature, holding time and internal stress.

In general, the reduction rates provided in the book are in a wide range. In actual use, the thickness and structure of the product, as well as the size and direction of the temperature and pressure during injection molding, should be considered. If the general product does not have a core support, the shortening is correspondingly larger.

Injection molds are basically divided into static molds and movable molds. Guangdong Plastic Mould

The static mold is the one with the sprue sleeve on the side of the injection head of the injection molding machine. A static mold generally consists of a sprue sleeve, a backing plate and a template.

Simple molds (especially those without a core in a static mold) also cannot use a backing plate. , just use a thicker template. The sprue bushing is generally a standard part, and it is not recommended to cancel it unless there are special reasons.

The use of the sprue sleeve is conducive to the convenient installation and replacement of the mold without self-polishing. Some special mold sprue bushings can be drilled or cut with a tapered wire. When part of the mold must be demolded from the static mold, a static demolding mechanism must be added.

The structure of the moving mold is generally a moving template, a moving mold pad, a demolding mechanism, a mold foot for installation and a fixed plate.