New Screw Flutes Mix Better Lab Batches.

A vertical, single-screw lab extruder with extraordinarily long 50:1 L/D and a new fluted mixing element shows marked improvement in compounding performance, says Randcastle Extrusion Systems Inc., Cedar Grove, N.J. Its new BT Compounder uses a fluted mixing element called a BT Mixer. The mixer is similar to a Union Carbide fluted mixer but with open, untapered inlet channels. Two such mixers are located in the screw's melting zone, upstream of the usual position for mixing elements.

Randcastle presented data on the mixing performance of the BT Compounder for the first time at PLASTICS TECHNOLOGY'S Continuous Compounding Conference last month in Cleveland. The company has developed a second-generation unit that reportedly gives even better mixing results.