Cool profiles from the inside out.

Crane Plastics Co. in Columbus, Ohio, has patented a cryogenic method of cooling the inside of a hollow PVC profile. The patent (U.S. #6,708,504 B2) describes pumping a liquid coolant at below 80 degrees F inside a hollow profile to cool it. The coolant, which may be liquid or gaseous oxygen, nitrogen, neon, hydrogen, or helium, is piped inside the part via a crosshead die, according to the patent. Crane Plastics Manufacturing, the custom profile division of Crane, has developed technology to put nitrogen gas inside a flat hollow PVC panel with thin (0.010 in.) walls and supporting ribs. Freezing the part from the inside prevents warpage and increases throughput, Crane says. The technology was developed at Crane's CPC Tooling division. The patent covers using the inside-out cooling technique in other processes besides extrusion, such as injection or compression molding. Tel: [phone] * www.craneplasticsmfg.com