Not necessarily in the same injection molding machine, twice molding; After the product is taken out of one set of molds, it is put into another set of molds for the second injection molding.

It can be processed by ordinary injection molding machine with relatively small equipment investment.

Not suitable for precision injection molding of dual-material and multi-material injection products; The molding cycle is longer, and the production efficiency is lower than that of two-color mold.