Purging compound achieves dramatic results in blown film applications

The Asaclean UF2 grade compound from Sun Plastech Inc. (Parsippany, NJ) is recommended for purging to and from polyethylene-based resins within a 170° to 320°C (340° to 608°F) processing temperature range in injection molding and extrusion applications. Literature on the compound also notes that it is suitable for blown film and cast film extrusion, but a recent development has Glenn Kornfeld, President of Sun Plastech, wondering if he shouldn’t rethink the wording.

It turns out that the UF2 grade can perform remarkably well in blown film equipment. That may even be an understatement, according to Kornfeld. “The compound can reduce the purging time from the typical eight hours to 2 1/2 hours. One of our blown film customers even achieved a cost reduction of more than 75%,” he said from the company’s booth at PLASTEC West in Anaheim, CA, earlier this month.

The UF2 grade compound is designed for color and material change, hot runner cleaning and shut-down and sealing applications. It does not work by chemical reaction—although Sun Plastech offers a full line of chemical purging compounds following its acquisition of Novachem in 2015, if you’re in the market for that—and does not require soak or hold-up time to achieve an effective purge.

Assaclean currently has a portfolio of 17 core mechanical and chemical grades of purging compounds.