By: Jim Johnson
November 19, 2013
DÜSSELDORF, GERMANY — Agr International Inc. wants to turn the way the PET bottle industry measures, manages and deals with crystallinity on its ear.
The Butler, Pa.-based company is nearing commercialization of new technology that will provide real-time crystallinity management for finished bottles created by the reheat stretch blow molding process.
"I believe it's a huge deal because it changes the industry paradigm from a responsive quality check to a proactive quality control," said Agr's Georg Wolfe during an Oct. 17 interview at K 2013 in Düsseldorf.
As chief technical officer for the company, Wolfe has spent the past year examining the crystallinity issue with an eye on creating a solution.
Crystallinity, in and of itself, is a good thing in the reheat stretch blow molding process. But you know what they say about too much of a good thing.
Bottle makers want a certain amount of crystallinity — essentially how molecules line up as a PET bottle is created to help with issues such as shelf life and bottle integrity.
But too much crystallinity will lead to bottle performance and appearance issues.
Bottles can become hazy and experience pearlescence, a whiting of the PET at the bottle's base.
Wolfe has spent the last year or so creating a real-time crystallinity management system that bottlers will be able to use as containers are being made.
Machine operators, historically, have taken a reactive approach to the crystallinity issue, tweaking the system as problems become apparent. But that way can create plenty of rejected bottles during the time it takes to manually resolve the problem by adjusting temperatures.
Agr's impending approach will use software to monitor the temperature of both the preforms used to make bottles, as well as the oven used to heat those units before they are turned into containers. This automation will allow for fine-tuning of the process to control crystallinity as well as material distribution in the molds.
"Right now, this is all done manually. So the guys are looking and they are tweaking things. They are tweaking the oven. What happens is the preform energy also governs the material distribution. If they are tweaking the ovens to get the crystallinity up, they are affecting their material distribution. So it's going haywire," said David Dineff, global product marketing director for Agr.
So Agr's idea is to create software to monitor and control that process. Testing will take place in the upcoming months with plans to have the system available next year.
"We haven't released the product yet, but we're working on trials over the next three to six months. But, essentially, what we've found is a relationship between preform energy and the crystallinity," Dineff said.
The new offering will be made through the company's Process Pilot family of products that already provides material distribution, defect detection and automated blow molder control services.
"Simultaneous real-time management of the process is huge," Wolfe said.
"The bottle is a very sophisticated item. People take that for granted, but there's a lot of sophistication that goes into a bottle," Dineff said.