Two-color prototype injection molding

We often seen two color on a plastic prototype.Take the bottom on the phone for example,buttons is black but the number 5 is transparent. So how does that work?

1,Injection mold two times:

Two sets of molds are needed, and the processing process is as follows:

First ,use common injection molding machine to make transparent prototype number” 5”,then put the transparent prototype” 5” into another mold to injection the black material.in this way ,the prototype will be two color after out of mold.

2,Two – color mold injection molding by two – color injection machine.
There are two back molds and two front molds. (The structure of the two front molds is basically the same.) Two rear molds are installed in parallel at the rear mold installation part of the injection molding machine, and two front molds are installed at the front mold installation part. Two-color injection molding machine has 2 nozzles (2 barrels), supporting 2 dryers, and 2 injection materials.

Injection molding process

After first mold closed production ,the number “5”of transparent material appear in the back mold.When mold open ,the back mold rotates 180 degrees. (That is, the positions of the 2 rear modules are reversed).

After the second mold closed production ,the black material inject cavity ,surround the number 5.After open the mold ,we can see two color buttons.