Rethinking Purging: A Strategic Approach to Injection Molding Productivity

March 5th, 2024

In the world of injection molding, every second of production time and ounce of material matters. It’s a high-stakes environment where efficiency and waste reduction are not just best practices, but the lifelines that keep operations profitable and sustainable. Yet, there’s one aspect of the process that has been historically thought to be a mere expense: the purging of the barrel and injection mold. Here at Slide, we aim to dismantle this perception and argue that purging, when approached strategically, isn’t just a cost but a significant opportunity for savings and heightened productivity.

The Misunderstood Necessity

Purging, the method of cleaning injection molds and machinery of one material or color before introducing another, has long been viewed as an unavoidable overhead. Our perspective focuses on immediate outlays such as price for buying purging compounds, unwelcome equipment downtime and related labor involved. However, this view is shortsighted, overlooking the broader operational and financial benefits that effective purging strategies can bring.

It’s crucial to understand the real costs associated with inefficient purging practices. These include:

• Increased Scrap Rates: Inadequate purging can lead to contamination and defects in produced parts, increasing scrap rates and material waste.
• Extended Downtime: Without effective purging, more time is needed to achieve clean material transitions, leading to extended downtime.
• Wear and Tear on Equipment: Inefficient purging can require more aggressive mechanical cleaning methods, accelerating wear on machinery.
• Quality Control Issues: Residual materials can compromise part integrity, leading to potential failures and customer dissatisfaction.

Viewed through this lens, the question isn’t whether you can afford to invest in purging but whether you can afford not to. To better understand this idea, we interviewed Slide’s Mold Release and Purging Expert, Jeff Lewis.

“Purging shouldn’t be seen as a task; it should be viewed as a necessity. It’s a proactive step that is crucial to every molding process.” - Jeff Lewis, Slide Products Purging Expert

With many years of experience in the plastics industry, Jeff has found that purging is one of the largest misconceptions within the business. Because it is often not done routinely, the process is commonly seen as a task and therefore a cost to molders. He argues that once the benefits of constant and correct purging are understood, it changes the dynamic from an expense to a savings opportunity.

The Opportunity in Strategic Purging
Rethinking purging from a perceived chore into a proactive measure requires a strategic approach, focused on optimization and waste reduction. Here are key factors to consider:

1. Invest in Advanced Purging Compounds
Modern purging compounds are designed with efficiency and effectiveness, capable of reducing time and material waste. While there’s an upfront cost, the return on investment exists from minimized downtime and lower scrap rates.

2. Optimize Purging Processes
Customizing the purging process to your specific operations can yield significant savings. This means determining the most effective techniques and compounds for your materials, machinery, and products in addition to training staff accordingly.

3. Leverage Purging for Preventive Maintenance
Regular, proper purging can extend machinery life and reduce the need for repairs. By removing contaminants and preventing buildup, you diminish fatigue on components, translating to longer intervals between maintenance shutdowns.

4. Reduce Material Waste
Efficient purging decreases the amount of material used to clean the system, directly preventing waste. Moreover, by mitigating scrap rates through improved part quality, you further lessen waste and associated costs.

In conclusion, we believe it’s vital for injection molders to reevaluate the role of purging within their operations. By shifting the perspective from seeing it as a mere expense to recognizing it as an advantageous opportunity for efficiency and cost savings, companies can unlock significant operational and financial benefits. The key lies in adopting a holistic and optimized approach to purging, leveraging advanced compounds and techniques, and integrating purging into the broader operational tactics. In doing so, this process becomes not just a part of the process but a driver of competitive advantage.

Slide Products offers a valuable resource with our Purging Cost Calculator. This tool affords processors the opportunity to realize their true cost of purging under their existing methodology, and how there could be huge time and monetary savings by making a change.

Here at Slide, we not only offer high quality purging compounds, but also the expertise to customize the process to your individual business needs. Learn more about our Top Tier Service program – it starts here!