Two-Color Molding vs. Insert (Two-Step) Molding

Two-color molding is done on a two-color machine. The first material is molded, then the mold rotates the part to the cavity served by the second barrel, where it acts as an insert and the second material is molded over it to form one integrated part. The machine has two barrels and two cavities; both shots run at the same time, with the part from one cavity becoming the insert for the next.

Two-step (insert) molding molds the first-material part on one machine, then places it as an insert into another mold where the second material is injected.

In short: with two-color molding, raw material goes into the machine and the finished two-material part comes out. With insert molding, the part to be combined is placed into the mold first and then overmolded.