Blow molding—whether extrusion or injection blow molding—poses unique cleaning challenges. Contamination in low-flow areas like accumulator heads can stretch changeovers from 8 to 24 hours and lead to scrap, product defects, and reduced uptime. But, with the right purging approach, you can drastically cut cleanup costs and cycle time.
Why Traditional Cleaning Falls Short
Many blow molders still rely on regrind resin or manual efforts to purge their machines. Although this looks like a shortcut, it often leaves residue behind, especially in accumulation heads or long flow lines. Contaminants may remain hidden until they cause streaks, delamination, or outright scrapped runs.
A Smarter Approach with Asaclean®
Asaclean® has evolved purging offerings tailored for blow molding's toughest areas. For most extrusion blow molding, chemical purging compounds and purging concentrates are recommended because they expand and clean through low-flow zones where mechanical compounds struggle.
Using Asaclean, many blow molders have halved their changeover times. One report even shows a reduction from over four hours to less than two hours when switching from virgin resin purging to Asaclean®—saving labor, downtime, and costs.
How It Works in Practice
Begin by raising die temperatures 20–30 °C and purging out residual resin. For highly contaminated systems, removing screen packs or even dies helps, especially before using filled grades. Load Asaclean® into the hopper, begin at low screw speed, and slowly increase to max safe RPM. Periodically pausing screw rotation ensures dwell time and deeper cleaning. When the purge comes clean, switch back to normal resin and restore machine settings.
In systems with accumulator heads, using low-flow–optimized purges lets you fill and purge multiple cycles—25 %, then 50 %, up to full volume—to ensure the head and manifold are clear.
Long-Term Gains You Can Count On
Adopting a proactive purging schedule—before color changes, during extended runs, or ahead of shutdowns—prevents the buildup of carbon, black specks, and contaminant layers. This maintenance mindset means fewer emergencies and more predictable operations.
With the right grade and timing, blow molders reduce scrap, accelerate changeovers, and avoid costly screw pulls. Many report consistent savings of over 60 % in downtime and scrap material.
In Summary
Blow molding doesn’t have to be the bottleneck in your operation. With chemical or concentrate purging compounds designed for low-flow environments, you can reduce maintenance hours, defects, and downtime. The result: cleaner accumulator heads, smoother startups, and a more reliable production schedule.
If you’re dealing with slow changeovers or frequent defects, it’s worth speaking to a purge expert. Request a sample, try a purge protocol, and see the difference firsthand.
Ready to see the difference Asaclean® can make in your production? Request a free sample today and experience how our purging compounds can enhance your color change efficiency, reduce waste, and improve your manufacturing process. Our team of experts is here to guide you through the process and help you achieve the best results. Contact us now to get started!
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