BLOW MOLDING: New Software Optimizes PET Bottle Crystallinity

Sensors determine the lowest possible blowing temperature without inducing pearlescence.

At the recent K 2016 show in Germany, Agr International Inc., Butler, Pa., introduced PET bottle optimization software that maximizes crystallinity without sacrificing clarity. The concept is to find the lowest preform blowing temperature possible—to induce maximum crystallinity and performance properties—without causing pearlescence that clouds the bottle. Newly commercial, Agr’s CrystalView software (previewed in developmental form at NPE2015) uses a set of vision components mounted inside a reheat SBM unit.

As bottles exit the mold, CrystalView scans every bottle for the onset of pearlescence, which it can detect well before the human eye can perceive it. It’s an automated, hands-free means of optimizing PET bottle properties without overstretching. According to Agr, bottle makers often run a little warmer than necessary to prevent pearlescence. With CrystalView, the system automatically reduces preform processing temperature by as much as 10° C (18° F), with these benefits:

• Topload increased by up to 17%;
• Volume expansion (creep) reduced by up to 38%;
• Shelf-life increased by up to 10%;
• Burst pressure increased by up to 17%;
• Oxygen transmittance reduced by up to 7%;
• Squeeze resistance increased by up to 7%;
• Energy consumption reduced by 7-10%.

CrystalView is available as an add-on option to Agr’s Process Pilot automated SBM machine management system, including retrofits to existing systems.