Cost Saving Solutions

Purging Compounds for Carbon Contamination & Black Specks

Every processor has dealt with carbon contamination and black specks. Gels, black spots, specks, and other contamination form when processing resins start to degrade within your machine. Once you notice defects in your parts, you need to address the issue immediately or your scrap will start piling up.

Whether you’re experiencing black specks at start-up or during your production run, Asaclean® helps you remove carbon contamination and get back to running good parts in no time.

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Conquering Carbon Contamination

Plastics manufacturers know the frustration well.

You’re running great parts with no issues, then suddenly see black specks/carbon in your product. Maybe you’re starting up after a holiday shutdown. Your first shift begins production and immediately sees bad parts. This is not how you want to start your week.

Carbon may appear and disappear at irregular intervals during your production run seemingly without cause, leading to concerning scrap.

If you’re experiencing black specks/carbon during your production run or at start-up, there is some level of contamination present within your system.

Carbon contamination adds critical hours to otherwise simple production runs and results in lots of scrap, reduced profits, and jeopardizing deadlines along with it.

The good news is, Asaclean®’s world-class Purging Compounds quickly and completely eliminate carbon contamination whether you’re dealing with issues at start-up or during a production run.


On average, Asaclean® customers save 64% on carbon contamination and black specks.

Before explaining Asaclean®’s solutions, let’s look at some likely causes of black specks and the areas where contamination could be accumulating in your machine.

  1. Overheating processing resins lead to degradation.
  2. Additives, color concentrates, and fillers degrade under heat.
  3. Heat-sensitive resins degrade during changeovers.
  4. Too much residence time in the barrel results in oxidation/degradation.
  5. Excessive shearing of the resin is caused by back-pressure and incorrect screw surface speeds.
  6. Low-quality production resins or regrind.
With Injection Molding, contamination is most likely to accumulate on:
  • The check ring
  • Hot runner manifold
  • The trailing edge of screw flights
  • The screw
  • Nozzle
  • Valve gates
With Extrusion, carbon contamination issues are generally found on:
    • Vent areas
    • The trailing edge of screw flights
    • Breaker plate/screen pack
    • The die
    • The screw
    • Melt pumps

Asaclean® Purging Compounds are Best Your Solution for Carbon Contamination

Solving Carbon During a Production Run

1. Once you notice carbon contamination, a strong cleaner like Asaclean® EX Grade Purging Compound will be necessary to clean out your machine in-between production runs

Asaclean® Purging Compounds eliminate contamination and no product on the planet is better than our EX Grade. It will get you running good parts again in no time.

For carbon issues with super-engineering resins, we recommend our PX2 Grade. PX2 has the highest processing temperature range of any purging compound on the market and has incredible cleaning power.

“Asaclean® has always been great with removing carbon. It completely cleaned out the degraded material. We were able to go right into production on one of our clear styrene parts with no issues.”
Dave S. , Production Manager, Custom Molder, Georgia

Avoiding Black Specks at Start-Up

4. Seal your screw and barrel with Asaclean® Purge before extended shutdowns

Sealing with an unfilled purging compound like U Grade or NCR Grade during shutdowns will keep you from dealing with defects when you start back up.

Sealing with Asaclean® has kept our machines in great shape and startups from an extended shutdown are a breeze.
Ray D. , Plant Manager, Custom Molder, Southeast

Protect two of your most important assets: time and money.

Contamination doesn’t have to derail your operation. We can help you get the job done better and faster, using far fewer pounds of purging products.

We always recommend working with an Asaclean® Purging Expert to develop your own, customized Purge Program that will help you avoid all contamination in the first place. An effective purge and preventive maintenance program will help extend the integrity and life cycle of your equipment and improve the quality of the parts you produce.

Your dedicated Asaclean® Purging Expert will meet with your team onsite to answer questions and train all shifts on how to achieve the best possible results using Asaclean®.


Struggling with Carbon? Request Your Free 10-Minute Expert Purging Consultation

With over 200 years of processing experience and over 20 industry-leading Purging Compounds designed for your specific process, Asaclean® offers you the best possible combination of performance and service to get the most out of your process.

Contact an Asaclean® Purging Expert right now to get started

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