As part of our technical service to support trials of new purge options, one important step is the pre-trial preparation. This prep can be a discussion at the plant (during live trials) or via video conference (eg TEAMS) that gets the process engineers ready to run a trial with the purge product’s specific recommended procedure. A trial run with any variant to what’s “officially” recommended runs the risk of getting results that might need to be discarded, as the question would remain on “how would the product have worked had it been run correctly?”
This being said, sometimes our recommended adjustments to different machine parameters simply cannot be achieved, as some machines won’t be able to perform the request, or sometimes the operator will have restrictions to what is allowed to be adjusted. Some examples: maximum back pressure won’t keep a screw forward in the zero position due to a leaky check valve, inputting maximum injection speed for high-velocity shots won’t net the actual result in shot speed (machine issue), recommended temperature increase not permitted due to limitations placed by machine manufacturer to avoid thermal expansion, minimum RPMS can’t be achieved on high-speed extruders that don’t offer a slow enough option during chemical purge soak periods, these amongst countless others.
Fortunately, these instances don’t have to be deal-breakers. The first purpose of the pre-trial discussion is to educate the end-user on how and why the purge product works, arming the user with the knowledge to use the product to the best of its abilities using their own knowledge of the machines they use every day to help get the most performance come trial time. In place of just sending official written procedure that often tends to be more general than specific, the pre-trial chat lends to a more cooperative effort that allows for more custom fit and machine/application-specific procedure recommendations. Need more performance from a chemical grade but higher temperatures are not an option? We’d look at an increase to the soak period, a grade that can achieve more reaction at lower temps or increase mix ratio if trialing our concentrate grade. Can’t keep screw forward with maximum safe back pressure? We’d look at manual control of the screw to keep it forward as best we can during that step of the procedure. Can’t bring down RPMs to allow a chemical purge grade to soak for recommended times? We can come up with a starting and stopping of the screw sequence that could net nearly the same effect.
If you’d like more info on how you can benefit from a customized purge program that addresses both cleaning needs and machine limitations or variances, contact us. I’d like to get to know more about your operation before making product and procedure recommendations.
Learn more about how to reduce production downtime and protect your profits with a purging compound.
Lenny Gutierrez is a Purging Expert & Technical Sales Representative with over 20 years of experience in the plastics industry. He was responsible for the growth of the Mexican & South American Asaclean markets before sharing his expertise and friendly disposition with molders, extruders, and blow molders in the midwest.