Plastics Injection Molder Eliminates Unnecessary Screw Pulls

I visited an Injection Molder located in the Southeast, United States. They had experienced some turn over in their molding department and were having some issues and needed training. As a Technical Sales Representative of Asaclean, I believe Customer Service and Support are one of our greatest assets. I quickly scheduled a trip to their facility. As I visited with each individual on their production floor it seemed that they had veered away from the proper Asaclean purging procedures. This didn’t surprise me. The Process Engineer stated that their 1500 ton injection molding machine was in bad shape; they believed that the check ring was either cracked or leaking. While they were running the machine they would get short shots and flash on their parts. This machine was running a nylon resin and had been running for many months.

Although they had been cleaning with the Asaclean, they had not been purging correctly. They had eliminated steps from our instructions.

So I let them clean the machine with the Asaclean using their method. We ran a natural behind the Asaclean to displace it and the machine looked clean. We then purged again using the proper Asaclean purging procedures. They were very shocked to see the amount of black nylon that was still in the machine. By following the correct Asaclean purging procedures we were able to remove the built up nylon that had been degraded and stuck to the trailing edges of the flights and on the check ring. We then displaced the Asaclean using the proper procedures and started the machine back for production.

The machine started up with only a couple of normal start-up short shots, and went straight into good production. The machine held a consistent cushion and we had eliminated the short shot and flash issues. This saved them about 12 hours of down time and labor since they were going to pull the screw, and it normally takes 12 hours to pull the screw, clean it, and reassemble. Not to mention the savings from not having lost production hours running short shots and flash prior to getting the screw cleaned.

That’s 12 hours of production they could never get back!

During my 34 years of working in the injection molding industry, one thing I always seem to hear from processors that they “just don’t have time”. Often it seems they get so caught up in the time constraints of manufacturing that they start to cut corners, they eliminate steps in the process and procedures and so on.

Cutting corners in purging procedures is no exception, in fact, it seems even more prevalent. This always results in higher scrap, excessive wasted resin, more downtime and even causing screw- pulls that are likely not necessary. DON’T GET CAUGHT CUTTING CORNERS! Follow the purge instructions.