A new screw runs 15 to 20° F cooler than typical CPVC screws, significantly increasing uptime in CPVC extrusion, according to American Maplan Corp., McPherson, Ks. Maplan built the first version two years ago and has steadily improved it since. CPVC has higher heat and chemical resistance than standard rigid PVC, but the melt is also more viscous and subject to degrading. Maplan’s new screw design is available for any counter-rotating conical or parallel twin-screw extruders and uses a combination of a proprietary balanced flight depth, surface area, and flight pitch. There are a half dozen in the field, Maplan says. CPVC pressure pipe is used for gas, hot water, chemicals, and fire suppression. (620) 241-6843 • www.maplan.com
823 South 81 Bypass McPherson, KS 67460
Phone (620) 241-6843 Fax (620) 241-2142
Editor PickSizing the Barrier Gap
Here’s a less complex way to properly size the barrier gap for barrier screws.