Novel S-Shaped Die Is Key to Flexibility.

An unusual S-shaped die adapter allowed a maker of PVC and polyethylene pipe to produce fiber-optic conduit without making a costly switch to crosshead dies. Such dies are used to insert tape that helps pull the fiber-optic cable through the conduit. For this processor, that would have meant redoing its plant layout and repositioning extruders at right angles to the production line. Instead, Blue Diamond Plastics in Middlesboro, Ky., developed S-shaped dies to thread tape into the conduit without moving any extruders.

When Moore Diversified Products bought Blue Diamond three years ago, it liked the S-dies so much that it incorporated them on nine new lines for a conduit plant in El Reno, Okla., that started up last August. The lines use Trident Series 3500 extruders from PTi-Processing Technologies Inc., St. Charles, Ill.

S-dies come in especially handy because fiber-optic manufacturing has moved away from tape insertion toward blowing cable through the conduit instead. "We only put tape in 30-40% of conduit now," says Moore Blue Diamond general manager Ken Flammang. The S-die offers the flexibility to make conduit with or without tape--and other products as well.