Along with the molding machine and robotics, a very key piece to making a plastic part is the mold itself. Now the mold or die (as it is sometimes called) consists of the mirror image of the part. There are a front or cavity side and the rear or core side. These are cut and formed on a CNC milling machine that can be so precise it can cut steel to within .001". After the part design has been finalized the mold is made to match the part. During the mold making process there are a number of components that make up the mold. I'm will not go into great detail, but I will point out a few key components.

Guide pins of the mold eliminate the mold halves from becoming out of position with each other. Just as the name states guide pins help guide the back half to the front half or the front half to the back half. This will ensure the cavity and core fit back together without any damage each cycle.

We have channels (which make a circuit in and out) cut into the steel plates that will run either water or oil through the mold to help cool the part. These channels can be just a couple all the way to 20 or more different circuits.

Vents are cut running from the mold features outward. Vents exist so air can escape the mold as the plastic is being injected into the mold.

Ejector pins are made to run from the back of the mold to the front of the core side. These assist in the removal of the molded part. Ejector pins can also be vented to help air escape the mold as the plastic is being injected.






Molding basics.....