Longer L/D for PVC

Twin-screw extruders for PVC profiles are getting longer and longer to achieve higher outputs and a wider processing range for different formulations, says Krauss-Maffei Corp., Florence, Ky.

Twin-screw extruders for PVC profiles are getting longer and longer to achieve higher outputs and a wider processing range for different formulations, says Krauss-Maffei Corp., Florence, Ky. The firm is phasing out its 26:1 L/D PVC extruders in favor of new 32:1 models, which come in 75, 90, and 114 mm diam. Maximum output rates range from 750 lb/hr to 1600 lb/hr. An even larger (133-mm) machine is being designed.