Published On: Thu, Nov 25th, 2010

W. Amsler’s new preform cooling system improves bottle productivity

W. Amsler Equipment Inc., a Canadian manufacturer of all-electric, reheat stretch-blow molding machines based in Richmond Hill, Ontario, has developed a unique preform cooling system which delivers major productivity improvements for manufacturers of PET containers.


W. Amsler has bought the first system and has achieved higher output for production of thick-walled PET liquor containers.

Amsler’s new preform cooling system uses increased air flow in the oven to reduce the surface temperature of the preform. This results in minimal temperature differential throughout the preform, thus inducing less stress and creating faster molding cycles. In addition, the increase in air flow improves production of colored bottles, reducing the chance of burning the colored preforms.

The system uses the same heating element (infrared short-wave emitters) but replaces the standard reflectors with a plenum (chamber). The air flow through the plenum slots cools each preform directly and more precisely. Instead of compressed air, Amsler relies on its standard integrated filtered air supply at no additional cost in power consumption.

Westbridge Inc., a Calgary, Alberta-based blow molder of PET containers for carbonated soft drinks, water, and liquor, installed the new preform cooling system on their Amsler two-cavity reheat stretch-blow machine and realized a 13.3% improvement in productivity for its thick-walled (0.210-in) 1.75-L PET liquor bottles, according to Harry Logan, Westbridge’s director of operations. The processor shaved a second off its cycle time, producing 1,107 bottles/hour compared to the previous 960 bottles/hour.

“We were able to heat the preforms at a higher temperature while still keeping the outer surface cool,” said Mr Logan. “By the time the preforms reached the blowing station they maintained a uniform heat profile throughout the preform’s wall thickness, resulting in a significantly reduced cycle time.”

Westbridge was able to install the conversion kit in less than four hours with minimal downtime. The company estimated a payback of less than four months. Amsler offers the preform cooling system as a retrofit on its full range of all-electric reheat stretch-blow machines.


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