What is the cost of purging? What is the cost of not purging?
There is a considerable difference in price among the various commercial types of purging compounds — all are a higher price per lb. than resins. The factors that need to be included in the cost issue to determine the “cost to purge” (an analysis developed by the Dyna-Purge Division of Shuman Plastics, Inc. — see “Cost To Purge”) are to calculate the: • cost of purge compound • cost of machine downtime (includes machine adjustment, soak and manual mixing) • cost of carrier resin • post purge cost of resin • cost of post purge downtime More importantly to consider is the cost of not purging. The processor will generate an inordinate amount of scrap, have reduced productivity, and will incur substantial opportunity cost. We encourage all plastic processors to use an effective commercial purging compound that is formulated for the process/resin /temperature needed to purge. Dyna-Purge offers 10 different grades to fill injection molding and extrusion applications.
