this kind of bi-injection molding machine is developed by SINO;additional injection unit making injection from the side of the mould cavity.
the mold can be installed on an ordinary injection molding machine,and  the mould core insert can be rotated 180 degrees, injection machine will inject one plastic material just as a ordinary plastic mould, and injection unit will inject another plastic material from the cavity side.
The injection unit can be connecting with any ordinary injection machine, it is easy for operation and the cost is much lower than double color injection machine.