what is the difference between two-color injection molding and second-shot injection molding?

 Do you know how the plastic products in many colors are made we always see in our daily life. In plastic injection molding process , both processes two-color injection molding and second-shot injection molding can get this effect .

 

1，Two-color shot injection molding aslo known as two-color mold injection, it is that make two plastic materials molded in twice in the same injection molding machine, but the products only to be ejected out in once, which process completed only need one set of mold, a special two-color injection molding machine required. A real two-color mold is that one material molded completely, then rotated 180° for another material molded, means the same front mold,the different back mold. Two-color injection molding have the advantage of high efficiency, low cost if order quantity is large .

 

 

 

2，Second-shot injection molding is also called overmolding injection molding. Two plastic materials are not necessarily molded in the same injection machine, but are molded in twice, after the product is taken out from one set of mold, then put into another set of mold for the second injection molding(overmolding). Therefore, in general, this molding process is usually completed by two sets of molds, and no a special two-color injection molding machine required .

 

Second-shot injection molding is to first make a color plastic part in the first single-color injection molding machine, and then manually put the product into the second mold for molding again. Because it is difficult to place it exactly by manual, it will cause the product to have a sharp edge after it ejected out , strain, mismatch and other surface quality problems.

 

 Second-shot injection molding is to take out a part of the product after injection molding, and then put it into another injection molding machine for injection molding again. The efficiency will be slower and the cost will be higher, but the cost will be lower if the order quantity is small.