Agr International beta testing crystallinity in bottles
The company, which works with Suntory, Coke, Pepsi, Kirin, P&G and Nestle, hopes to commercialise the technology in Q4 2014.
“We are currently working in the area of crystallinity management,” David Dineff, director of marketing, Agr International, told FoodProductionDaily.com
Blowmolder Control system
“This capability will make it possible to fine tune and control the process to maintain crystallinity and material distribution at optimal levels for every bottle in a production run.”
Agr International recently installed its Process Pilot Automated Blowmolder Control system at Graham Packaging which is co-located with a food processing plant in the US.
The containers Graham makes for the food processor have different finish diameters: a 43mm finish for the bottles, and from 63mm to 83mm for jars.
It needed to produce both types on a single Sidel blowmolder with a spindle diameter of 43mm and the Process Pilot uses software and sensors to manage material distribution throughout the container.
“The software, in conjunction with a bank of thickness measurement sensors, monitors the wall thickness at multiple points over the sidewall of a PET bottle during the production in the blowmolder,” said Dineff.
Bottle wall thickness
“In addition to monitoring changes in bottle thickness throughout the production run, the Process Pilot software interacts with the blowmolder and continually adjusts the blowmolders parameters to maintain material thickness at optimum levels.
"This is very significant since changes in the blowmolders operation, plant environmental conditions and material attributes as seen in different batches of preforms all contribute to process variability and affect the bottle wall thickness and performance.”
He added the software reduces bottle variations by adjusting the blowmolder for on-going process variations allowing it to run in a “closed-loop” fashion with minimal operator interaction.
“This is significant when producing very light bottles or, in this case, a very special type of bottle that relies on precise material thickness distribution for proper performance,” he said.
Sidel, Krones, KHS
The Process Pilot system is compatible with Sidel, Krones and KHS systems and Agr International has cooperated with all of these blowmolder suppliers on compatibility issues and interfaces with their equipment.
The operation has seen a big improvement in Cpks and PPKs since the Process Pilot and OptiCheck were installed on the blow-trim line and a 52.7% improvement in waste reduction.
David Piccioli, director, Global PET Technology Development, Graham Packaging said the blow-trim process is more challenging than traditional reheat stretch blowmolding.
He added the difficulty is getting the right material distribution in the body and thickness in the thread region.
“Its thickness gauge sensors precisely measure 16 different points on the side wall, around the perimeter of the bottle. Sophisticated algorithms analyze minute changes in material distribution,” said Piccioli.
“If there are any deviations from specifications, the Process Pilot automatically corrects the corresponding area of the blowmolder. Working in conjunction with the blowmolder controls, the system can simultaneously adjust multiple settings, lamps, blow pressure, and timing, for example, to maintain tight process control parameters with minimal operator intervention.”
