Marbleizing Units
Although most injection molding processes require optimum mixing of the melt when color additives are involved, some applications require that colors not be mixed. Instead, a marble-like appearance is desired to produce an artistic effect, frequently used in cosmetics, toys, sporting goods and housewares.
A marbleized effect can be produced using a plunger machine and some have used a specially designed screw and valve in their existing molding machines. We believe the most reliable method of marbleizing involves a special screw, a “torpedo†device and a specially designed valve and end cap. These essential components are:
- Short L/D Screw which feeds and conveys the resin downstream without fully melting.
- “Lawson” type valve which allows the free flow of the partially melted resin through it without any mixing effect.
- A “torpedo” devise that achieves a final shearing and melting of the resin without any mixing. The torpedo is held in place by a specially designed end-cap.
- An end-cap that is designed to accommodate the torpedo and hold it in place.
Marbleizing units using the described components have been used to successfully mold products made from SAN, PS, PP, K resin and cellulosics.