DÜSSELDORF, GERMANY (Dec. 18, 12:25 a.m. EST) — The developer of the Twinshot coinjection molding process has authorized Spirex Corp., a screw and barrel maker, to supply Twinshot technology to the retrofit market.
Youngstown-based Spirex manufactured the original Twinshot system, which features one screw inside another, hollowed-out screw, for Community Products LLC of Rifton, N.Y.
Community Products, which makes children's play equipment and products for handicapped children, developed Twinshot for its internal molding operation. The company claims Twinshot can be retrofitted to any existing injection press, after slight modifications.
Traditionally, coinjection molding has used a special press with two barrels. Twinshot uses a single barrel, but two separate melts, thanks to the screw-within-a-screw configuration. When both screws turn together, only the resin outside of the outer screw is moved forward. When the outside screw stops but the inside screw keeps turning, the second material on the inside chamber is pushed forward.
The melt accumulates in two layers as the screws are pushed back. A single, conventional injection cycle drives the combined melts into the mold.
Community Products has set up a marketing arm, called Twinshot Technologies. The firm exhibited at K 2001 in Düsseldorf.
Twinshot Technologies also wants to license the process to manufacturers of injection molding machines.