Material changes take place when transitioning from one resin to another. In many situations a commercial purging compound is recommended for this type of change over in order to reduce downtime and scrap. A commercial purge compound eliminates the remnants of the previous resin faster in comparison using to natural resin. Also, a commercial purge compound will assist in the difficult task of transitioning between resins with a large difference in operating temperature. Note, it is important to use a low residue purging compound that does not linger in production.