Strictly-Extrusion

A new grade of white mineral oil is said to be a cost-effective alternative to paraffin wax as a lubricant in rigid PVC. Hydrobrite PVC oil is a highly refined, free-flowing liquid paraffin that will not agglomerate like wax in storage or handling. It is said to be an excellent external lubricant for PVC pipe, siding, window profiles, fences, and doors.
This food-grade lubricant (as per 21 CFR 172.878 and 21 CFR 178.3620a) is said to be chemically inert, colorless, odorless, and tasteless. It also boasts excellent uv and color stability. It has been approved by the Plastic Pipe Institute and National Sanitary Foundation as a functional equivalent to paraffin wax for use at levels of 1to 2 phr in high-pressure PVC water pipe.

High-output foamed PVC sheet lines are now able to cool and control extrudate up to 1.25-in. thick, vs. a maximum of 0.8 in. before, says Krauss-Maffei Corp., Florence, Ky. The process combines the German company’s KMD164-26 (6.6-in. diam.) counter-rotating twin-screw extruder with a pair of special pre-cooling rolls to skin the hot foam before it reaches the chill rolls. Krauss-Maffei has delivered several of the new lines, including four to the U.S.