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Injection molding with an insert

Forming process where a core is placed in a mold and in which a molten polymer mass is injected around the core so that after solidification a non-homogeneous solid body is created.

Illustration of Injection molding with an insert

The process

Plastic pellets [1] are supplied via a hopper into a rotating screw [2] whose spiral shape moves the pellet forward through a heated chamber [3].The pellets are heated gradually and turns into a homogeneous plastic melt as it approaches the end of the helical screw.

The molten mass is pressed in a mold [4] as the entire screw is pushed forward by an applied pressing force.

Before casting begins the piece to be cast [5] is assembled. When the mold is then filled so that the part is surrounded and form a cohesive part of the end product. To ensure adherence, the molded part is often designed so that it is not the adhesion between the detail and polymer that attaches it to the detail but rather the shape of the part that locks it into the polymer.

Advantages and disadvantages
In comparison with alternative methods
Increased reliability: Reduced installation costs
Reduced labor costs
reduced weight, increased design flexibility
Expensive tools
Restrictions on the die size