Purging compounds for thermoplastic injection molding are available for use in high-detergency, high- and low-temperature, and enhanced general purpose applications. Reportedly, the compounds provide excellent cleaning ability and very low residue characteristics in cleaning hot runners in open or closed molds.

The newest compound, Asaclean UP Grade, is designed specifically for improved cleaning of polypropylene to facilitate color and resin changes. With an operating temperature range from 340 to 570F, it can be used to purge to and from PP-based resins, or as a shutdown sealant prior to polyolefin processing to help remove contamination. According to the company, in production-scale testing of the UP Grade compound with a 650-ton molding machine changing from black PP resin to white resin, results have shown as much as a 50% cost savings vs. purging with virgin resin.

Asaclean-Sun Plastech Inc., Parsippany, NJ
(973) 257-1999; www.asaclean.com