What Are Purging Compounds?
Purging Compounds (also known as commercial purging compounds or CPC’s) are products formulated to clean injection molding machines, extruders, and blow molding machines. They typically contain a base resin and other additives optimized to clean your screw, barrel, hot runner, and extruder die thoroughly and quickly. Purging Compounds are used by processors across industries including automotive, packaging, medical, consumer products, and many more
Difference between purging and flushing compound
| Feature | Purging Compound | Flushing with Virgin or Regrind Resin |
|---|---|---|
| Cleaning mechanism | Active cleaning. A purging compound is specifically engineered with active ingredients that use chemical, mechanical, or hybrid action to scrub and remove contamination. Some grades use heat-activated foaming agents to reach stagnant areas, while others use high viscosity to push out residue. | Passive dilution. Flushing relies on the new material to dilute and push out the old material. It does not actively clean away carbon buildup or baked-on color from the screw, barrel, or hot runner system. |
| Effectiveness | Highly effective. Purging compounds are designed to remove stubborn contaminants like carbonized deposits, degraded material, and leftover color, even from hard-to-reach areas of the machinery. | Ineffective. Flushing is slow and ineffective at cleaning anything other than the most basic residue. It can cause a “layering” effect, where new material simply coats the old contamination, leading to future defects. |
| Color and material changes | Faster and cleaner. Purging compounds dramatically shorten the time and reduce the material needed for a complete color or material changeover. | Slow and problematic. A flush can be a long and time-consuming process that often fails to remove all color and material, leading to streaks, black specks, and high rates of scrap. |
| Scrap and waste | Minimizes waste. While a purging compound is more expensive per pound, far less material is needed to achieve a complete clean. This significantly reduces overall material waste and lost production. | Wasteful. Flushing requires running large amounts of new resin, generating a high volume of scrap material that is either unusable or of low quality. |
| Machine maintenance | Improves preventative maintenance. Regular use of a purging compound keeps equipment clean and can often eliminate the need for costly, time-consuming screw pulls and manual cleaning. | Increases manual intervention. Because it is so ineffective, flushing often necessitates manual teardowns and cleaning, leading to more machine downtime and labor costs. |
| Cost over time | Cost-effective. The higher per-pound cost is offset by the huge savings from less material waste, reduced downtime, and improved product quality. The return on investment (ROI) is significant. | Ultimately more expensive. The low cost of virgin resin is an illusion. The high costs of wasted material, long downtime, labor, and high scrap rates make it a more expensive method in the long run. |
How to Use Purging Compounds Correctly?
Bajaj Plast’s R&D departments have been working for almost 38 years to engineer Purging Compounds that are perfect for your needs.
These are two important parts of this process:
1. Create a world-class product that delivers results
2. Develop procedures to repeat and optimize those results
The tricky part here is that neither the product nor the procedures will achieve the results on their own. You need to follow the correct instructions for your needs in to see your best possible cost savings. It sounds obvious, but you’d be surprised how often people choose to “wing it.”
Here are a few ways to avoid common purging mistakes:
1. Understand All Purging Compounds Are Different and Have Different Instructions for Different Situations
There is no one-size-fits-all purging compound. As processors gain experience, they may begin to treat all purging compounds the same way and run them using the same instructions. Maybe they used to purge at a previous job. Maybe they used to use a competitor and assume it’s the same thing. This is hurting your performance. Read the instructions and follow them. We spent years developing best practices to get the most out of each grade of Bajaj Plast. We didn’t write the instructions without making sure they are the best way to see the strongest results.
2. Different Purging Compounds Are the Best at Different Things
When most people think about Bajaj Plast, they usually think about EX Grade. It’s the best cleaner on the market and it makes screw pulls a breeze. But just because it’s the best grade for contamination and screw pulls, doesn’t mean it’s the best grade for everything. Work with an Bajaj Plast Purging Expert and we’ll be sure to get you “the best purging compound” for you. Keep in mind that it might not be the one that you think you need. We will figure that out together.
3. Establish a Baseline Before Starting Using Bajaj Plast
You need baseline processing data to know whether your purging compound is working for you.
How many good parts do you usually make? What is your scrap rate? How much material are you using now? What are your total costs (including labor)?
Understand these factors before you start your Purge Program.
Work with an Bajaj Plast Purging Expert to Develop Your Purge Program
Here's how the Purge Program process works
Introduction
- Have a short conversation about your processing challenges including resins, application, temperatures, etc.
- Diagnosis
- They will help you diagnose the cause of the problem and will consider potential solutions.
- Free Sample
- Our Purging Expert will send you a free sample of Bajaj Plast.
- Cost Savings Analysis
- Our Bajaj Plast Purging Expert will work with you to set up expectations on potential savings using Bajaj Plast®.
- Trial
We recommend having your Bajaj Plast Purging Expert on-site for trials because it’s important for you to have an expert standing by to offer best practices and help troubleshoot. We’ve seen hundreds of situations just like yours and are an asset when you’re deciding. If on-site trials are not possible, virtual options are also available.
Introduction of Purge Program
Once the trial is complete, your Purging Expert will build a Purge Program to help get the best results based on your situation. Your expert will train all shifts on Bajaj Plast best practices to make sure they see the best possible product performance. Purge Programs can include best practices for changeovers, sealing during shutdowns, changeovers, screw pulls, holding a bubble in blown-film extrusion, etc. A Purge Program looks very different based on your situation.
More Purge Doesn't Mean Better Cleaning
When it comes to Purging Compounds, less is more,Seriously.You may be surprised to hear that from a company that sells Bajaj Plast, but it really shouldn’t be all that surprising.We sell solutions. We want to sell you cost savings.If you need more Bajaj Plast to do a certain job, you will see lower cost savings.
We understand that If you aren’t happy with the performance of Bajaj Plast, you will probably start looking elsewhere.
We recommend the correct amount of product to get the job done. If you use too much product, your benefits will decrease. Follow our recommendations to get the most out of your investment.
About Bajaj Plast Pvt. Ltd.
Bajaj Plast Pvt. Ltd. is a leading manufacturer of high-quality masterbatch solutions, dedicated to innovation, sustainability, and excellence. With a strong focus on customer satisfaction and cutting-edge technology, we are committed to delivering superior products that meet the evolving needs of the polymer industry.
