December 26, 2007 - January 2, 2008 - This week's search of the week is Purging Compounds. Using purging compounds offer several benefits including minimized downtime, reduced scrap, it's easy to use, and it's economical. Purging is involves cleaning one color or type of plastic material from the cylinder of an injection molding machine or extruder by forcing it out with the new color or material to be used in subsequent production.