As an expert in purging compounds at Asaclean, I often visit injection molding and extrusion facilities nationwide. A common question I encounter is, "How can we improve our start-ups?" The solution often begins not at the start-up but with refining your shutdown procedures.
During the shutdown, processors frequently encounter several issues: failing to purge, leaving non-thermally stable resins, colorants, or additives in the barrel under heat, or leaving the barrels empty while banking the heat. These practices can lead to material degradation and the formation of black specs. For example, a non-stable white colorant might degrade under prolonged heat exposure, even if you use thermally stable polyethylene. We can tailor a purging program that minimizes these start-up challenges by identifying and addressing such issues. On average, a well-designed purge program can cut start-up scrap by 40-60%.
Success Story: Major Appliance Manufacturer
Consider a recent case with a major appliance manufacturer that produced white High-Impact Polystyrene (HIPS) sheets used to thermoform refrigerator liners. Their typical Monday start-up took up to four hours to eliminate black specs and meet quality standards for white sheets. Previously, they would end the week by leaving white HIPS in the extruder at a banked heat of 350°F, increasing to 420°F at start-up, without flushing the old resin.
This approach was costly, with each Monday start-up averaging losses of $3,800 due to downtime and scrapped parts. However, with a new purging procedure using Asaclean U Grade, they changed their approach:
- Friday at 5 PM: Purge out all white HIPS and black specs at production temperature with Asaclean U Grade.
- Shutdown: Fill the screw and barrel system with Asaclean U Grade and turn off the heaters.
- Monday Start-Up: Set temperatures to 420°F, use half a barrel of U Grade to purge the system, then flush with one barrel of HIPS before starting production.
The impact was dramatic. Start-up time reduced to just 30 minutes with zero rejects. The cost for each Monday start-up dropped to $1,300—a 65% cost reduction, saving $2,500 weekly. Annually, this amounts to $120,000 in savings.
Beyond Financial Savings
Adopting a structured purging program with Asaclean saves money and reduces wear on your equipment. It also alleviates workforce stress, elevates product quality, and enhances overall production efficiency.
Don't let start-up scrap erode your profits. Contact Asaclean today for a customized purge program evaluation. Together, we can achieve significant savings and boost your profitability through optimized purging processes.
Remember, effective purging leads to smoother start-ups and greater profitability.
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