When a medical injection molder in New England encountered persistent contamination issues, their production process was disrupted by excessive startup scrap. Running both rigid PVC and HDPE, they faced significant challenges in switching materials without carrying over contamination. This issue resulted in 100 scrapped parts at startup and 30 minutes of costly downtime.
They needed an effective purging solution to thoroughly clean their screw and barrel—and fast.
Both rigid PVC and HDPE (high-density polyethylene) are high-flow materials commonly used in injection molding. However, their high flow properties also make them prone to contamination during material changeovers. Contamination can impact part quality and dimensional accuracy, leading to startup scrap and downtime. Maintaining stringent quality control while minimizing production delays was critical for this molder's success.
We recommended the Asaclean U Grade Purging Compound to tackle these challenges, specifically designed for difficult material transitions like those between rigid PVC and HDPE. The U Grade effectively removes residual materials from the screw and barrel, preventing contamination between runs. It is also non-toxic and non-flammable, making it safe for medical applications.
The molder conducted initial tests with the U-grade and achieved impressive results. During their weekend shutdowns, they used approximately 13 lbs of the purging compound—about 4.5 lbs per purge—on three different injection molding presses. Two of these presses ran rigid PVC, and one ran HDPE.
These tests quickly showed the effectiveness of the solution. The molder reduced their startup scrap from 100 parts to just 3. Additionally, downtime dropped dramatically from 30 minutes to just 5 minutes. This marked a revolutionary improvement in their production efficiency, reducing waste and speeding up restarts.
This medical molder's success story illustrates the right purging compound's impact on injection molding efficiency. By significantly reducing startup scrap and downtime, they were able to streamline operations, increase productivity, and improve overall part quality.