Spirex Plasticating Systems & Solutions

Twinshot Co-Injection Technology


Twinshot sample part

Pioneering — Proven — Profitable

Do you want to...

· Reduce your resin costs by 35% or more?
· Save on labor and maintenance costs?

…then Twinshot may be for you!

The Twinshot patented co-injection technology is a cost-effective process that can give you a distinct competitive advantage within your marketplace by significantly reducing part cost while improving product quality. It’s a single injection unit , co-injection system that can be easily retrofit to your current screw/barrel injection molding machine.

Twinshot logo Available only from Spirex, Twinshot enables a conventional machine with a single barrel and screw to inject two materials in one operation, with one material totally enclosing the other. This new co-injection technique removes the obstacles to widespread co-injection utilization while preserving all of the traditional benefits. Simplicity and low cost differentiate this innovative technology from other co-injection processes. With this new system, virtually any custom or proprietary molder can afford co-injection equipment.
  • Single screw, single barrel, single recovery, single shot, single cycle... two materials.
  • Two independent melting sections (one for the skin material and the other for the core material) with multi-zone temperature control.
  • Single shot mold fill. The first part of the shot is skin; the second part is core.
  • Mold fill follows fountain flow principles causing skin material to fill the outer geometry of the part and cool as the inner material flows through the molten core.
  • Volume is controlled by varying primary or auger feeder screw speeds.
  • Result is a three-layer or "sandwich" construction A-B-A.