Solution for Carbon Build Up On Screw

Black specks showing up in parts can be a costly issue for many thermoplastic processors. Scrapping part after part that is contaminated with carbon specks results in excessive downtime and wasted resin. In extreme situations, companies using resin/regrind as their current purging may have to pull the screw and manually clean it when the carbon persists. Depending on the size of the screw this job could take anywhere from a few hours to all day.

Moulds Plus International was contacted by an injection molder who had been struggling with black specks for 48 hours. For years they had basically ran virgin resin through the machine to flush out the carbon and when the carbon issue would escalate they would pull the screw and clean it manually. A screw pull and manual cleaning would take one employee roughly eight hours.

An Ultra Purge representative evaluated the issue this company was experiencing and decided that the Ultra Purge 8416 was the appropriate grade for them. The Ultra Purge representative attended the trial with the company and after purging the machine multiple times was able to successfully remove all the of carbon. As a result, using the Ultra Purge kept the injection molder from having to pull the screw and manually clean it. The injection molder now has instituted a preventative maintenance program to keep carbon from forming on the screw and now they always use Ultra Purge when shutting down a machine.

In situations where heavy carbon build up has occurred on the screw it may require multiple purgings with the Ultra Purge. After the screw is clean and a preventative maintenance program is determined only one half to one full barrel capacity of Ultra Purge will be required to keep the screw clean. Additionally, shutting the machines down with Ultra Purge is also a good way to keep the screw free from carbon and in return will make the startup much faster.

Before Using Ultra Purge

Problems with Purging Black Specks

After Using Ultra Purge

Purging Black Specks with Ultra Purge