Injection molding is a process in which a molten plastic is injected into a closed mold having a relatively low temperature through a nozzle under high pressure. Both thermoplastics and thermosets can be injection molded. It can be used to make various box-type packaging containers, such as various turnover boxes and small boxes.
In order to facilitate the demolding of the molded part, a suitable draft angle must be considered when designing the container. The draft is too small, the demoulding is difficult, and the surface of the container is damaged; if it is too large, the dimensional accuracy is affected.
The draft angle varies depending on the shape of the plastic part, the type of plastic, the mold structure, the surface roughness, the molding method, and the like. Generally speaking, the commonly used slope of the plastic part along the demolding direction is 1 degree to 1.5 degrees, and the minimum is not less than 0.5 degree.