What is said to be the first “hybrid” purging compound, specifically engineered for PP color changes, has been launched by the Dyna-Purge division of Shuman Plastics, Depew, N.Y. Dyna-Purge A reportedly combines key features of both mechanical and chemical purging products, with advanced non-hazardous ingredients that reach all stagnation areas and break down the color contamination.
Commissioned by the company, an extensive independent study on Dyna-Purge A by Penn State Erie, The Behrend College, Erie, Penn., compared commercial mechanical (abrasive), chemical purging compounds, and in-house resins for purging during PP color changes. In both purging and post-purge results, only Dyna-Purge A left the injection molding machine clean and free of contamination. Results showed that the purging process successfully transitioned from black to natural PP in only seven shots using the new hybrid purging compound.
Engineered to exit the machine with the next production resin, leaving behind no residual purging compound, Dyna-Purge A is designed for a variety of applications including hot runners, profile, sheet and cast film, with no minimum clearances. Unlike most chemical purging compounds, it requires no soaking or temperature alterations, has no noxious fumes and odors, and no residuals.