Signs Your Production Line Needs a Better Purging Process

As we all know, the current manufacturing environment emphasizes the importance of efficiency and quality, but the root of all the problems associated with the manufacturing process can be attributed to a single factor: the purging process. 

Are you tired of facing defects, contamination, color streaks, and other issues? It might be the right time for you to think about the purging process.

What exactly is the purging process, and why does it have such a huge impact? In short, the purging process refers to the process of removing the remaining materials from the machine, especially during the change of materials, colors, or shutdowns. 

It has a huge impact because a proper plastic purging process will guarantee a better production process, while a wrong purging process can cost you thousands of dollars.

Let’s discuss the clear signs of the need for a better purging process and the impact of a better purging process on the quality, waste, and efficiency of the process.

What Is a Purging Process in Manufacturing?

Before discussing the signs, it is essential to know what the purging process means.

The purging process refers to the process of eliminating any remaining raw materials, deteriorated polymers, color, and impurities from the equipment, such as the extruder, injection molders, and blow molders.

In the plastic industry, the plastic purging process is of critical importance. In the plastic industry, the purging process is critical, especially when changing from one material to another, such as changing the color of the plastic material.

What the Machine Purging Process Achieves

When the machine purging process is conducted correctly, the following benefits can be achieved:

• Clean material flow
• Less contamination
• Less scrap
• Faster color change
• Product consistency

When the machine purging process is not conducted correctly, the results will appear on the final product and on the bottom line.

1. Frequent Color Contamination

One of the most noticeable signs that you need to improve the purging process on your production line is the presence of color streaks.

If you and your team are having trouble getting clean color transitions, that’s a surefire indication that the material purging process you are using is not effectively cleaning out the previous material, whether that’s resin, color, etc., from the barrel, screw, and hot runners.

Why This Happens:

• Not properly cleaning the equipment when changing the material
• Using the wrong material for the purging process
• Not following the proper equipment purging process
• Buildup of residue in the dead zones

1. Increasing Scrap Rates

If the amount of scrap is increasing without a clear reason, then the problem might be related to the purging of the machine. 

The residuals that are left inside the system can break down and degrade due to temperature and pressure. This can result in:

• Black specks
• Burn marks
• Flow lines
• Poor structural integrity

A suboptimal plastic purging process can result in degraded plastics remaining inside the system. This, in turn, can contaminate new production batches. This can, over time, result in more waste and decreased profitability. 

If the amount of scrap is increasing significantly after changeovers or after a stop, then the purging of the production line might be suboptimal. 

1. Longer Downtime During Changeovers

Changeovers are a vital part of production. If the changeovers are taking a long time, then this might be a sign that the purging of the machines is suboptimal. 

A good purging process should, above all, reduce the amount of manual cleaning, reduce the amount of disassembling of the barrels, and reduce the amount of time to change resins and restart the machines. 

When the material purging process is not standardized, this often means that people are using guesswork. This can result in more changeover times.

Also Read: PET Preforms: The Importance of a Good Purging Compound

1. Persistent Black Specks or Burn Marks

Black specks are a common problem experienced in the manufacture of plastics. However, they come with a cost. Black specks normally occur because the degraded material is not properly purged during the purging process.

Sometimes the temperature inside the machines is too high. This causes the material to degrade. Without a proper purging process for the machines, the degraded material sticks inside the machines. Later on, the degraded material ends up in the final products.

If black specks continue to occur after cleaning the machines, this is a sure indication that the current industrial purging process is not effective in accessing all the hidden areas where the buildup occurs.

1. Inconsistent Product Quality

When the quality is not consistent despite the use of the same material and the same settings on the machines, it is a sure indication that the purging process is not effective.

When the material is not properly purged during the material purging process, the final product is normally contaminated. Such contamination affects:

• Mechanical strength
• Surface finish
• Dimensional accuracy
• Transparency

When the quality control department is finding it difficult to ensure consistency in the final product, the need for a better purging process is a top

Also Read: 5 Ways Purging Compounds Can Help You Achieve Consistent Product Quality

1. Excessive Material Waste During Purging

Ironically, some organizations are guilty of overpurging, not underpurging. If you are using a lot of resin for machine cleaning, yet not getting clean results quickly, your machine purging process may not be effective.

What are the signs of wasteful purging?

• Long purge times
• Large amounts of resin usage
• Trial and error
• No standardized equipment purging process

Optimizing the plastic purging process can save you a lot of wasted resin.

1. Operator Inconsistency

Are different operators using different techniques for the production line equipment purging process? If yes, then the results will not be consistent.

If the material purging process is not documented, the results will not be consistent. Inconsistency will cause inefficiency.

Also Read: Efficiency in the purging process for thin wall packaging manufacturing

What should a standardized equipment purging process include?

• Temperature settings
• Purging compound usage
• Steps to follow
• Duration and pressure settings

If the material purging process is left to the operators, then the process needs to be optimized.

1. Frequent Equipment Maintenance Issues

The consequences of ineffective purging not only impact product quality but also have a lasting effect on equipment reliability.

Barrels and screws are prone to increased wear and tear due to residual buildup. An ineffective purging process on machines causes material to carbonize. This may lead to:

• Damage to screws
• Nozzle blockages
• Hot runner blockages
• Increased maintenance costs

The purging process helps protect machine components from buildup.

If maintenance frequency is reducing or components are often replaced, it could be a purging process issue on your production line.

How to Improve Your Purging Process

If you have noticed any of the above signs, then it is the right time to enhance your industrial purging process.

Here is how you can do it:

1. Standardize the equipment purging procedure

Develop a procedure for the equipment purging process that is followed by everyone who uses the equipment.

1. Use the right purging compounds

Different equipment requires different purging compounds. It is recommended to use the right compounds for the equipment during the plastic purging process.

Also Read: Why Choose Purging Compounds Instead of Resins?

1. Train the operators well

Everyone working on the equipment must be aware of the equipment purging process and its importance.

1. Monitor the purging metrics

Monitor the equipment usage statistics before and after the improvement of the equipment purging process.

1. Schedule preventive maintenance

Proper equipment maintenance is required for a proper equipment purging process.

Final Thoughts

The purging process, although not always receiving the attention that it deserves, is of great importance to the maintenance of production quality and efficiency. 

In a production plant, if there is a problem of color contamination, too much scrap, long changeovers, and/or black specks, then there is a need to improve the plastic purging process. Knowing what is a purging process and a standardized equipment purging procedure can change the face of a production plant. 

Optimizing the purging process of equipment and the production line’s purging strategy is a way to reduce waste, protect equipment, and maintain product quality. 

In a highly competitive production plant, small improvements in processes can translate to big gains. And sometimes, this begins with something as simple yet powerful as a better purging system.