Ultra Purge Speeds Up Black to Natural Polypropylene Color Change

A Moulds Plus International technical sales representative recently visited an injection molder in Missouri that was experiencing difficulties with a polypropylene black to natural color change (see parts below). The molder had been using natural resin to purge the barrel and hot sprue of the 550 ton press. Interested in improving the downtime and scrap the company approached Moulds Plus International for a free sample of Ultra Purge to test. The Ultra Purge representative gathered all the relevant information on the color change and determined the Ultra Purge P-O grade to be the best solution for this particular color change. The injection molder arranged to have the Ultra Purge rep visit their location and test the sample with them in person.

Typically the company would spend roughly one hour purging the black out with the natural resin before they were producing acceptable parts. The downtime cost per hour for this particular mold was $90. The scrap produced on this job was able to be used on other regrind jobs the company had in house, thus, the only cost associated with scrap is the energy consumption and labor. Below is the cost analysis comparing using natural resin to purge the machine to using Ultra Purge. Ultra Purge reduced the downtime by 70% which resulted in saving the company $43.05 for this particular color change. The molder is now using the Ultra Purge on all their dark to light color changes.

Color change: Black PP to Natural PP Units Natural PP Ultra Purge
Total Purging Material Cost USD 0.00 19.95
Time required for purging Min 60 18
Down-Time/Lost Production Hourly Cost USD/hr 90 90
Total Down-Time Cost USD 90 27
Total Cost per Purging USD 90 46.95
Total amount in USD saved per color change using Ultra Purge USD 43.05

Reduction Down Time

70%