Amcor Rigid Plastics has expanded its compression blow forming (CBF) platform with a new 20-cavity CBF machine for production of high density polyethylene (HDPE) pharmaceutical bottles at its Youngsville, North Carolina, the US facility.
The CBF20 machine, supplied by Italy's Sacmi Imola S.C, provides the same processing and performance benefits as the CBF12 (12-cavity) while meeting the high-production requirements of pharmaceutical customers, according to Amcor.
With the same footprint as the CBF12, the new CBF20 provides annual production output of 80-90 million containers per year.
"This is an unprecedented accomplishment in terms of the level of production on one mold," said Greg Rosati, Amcor's Marketing Director for Healthcare. "This further reinforces compression blow forming's position as a breakthrough process for the production of pharmaceutical containers, delivering high quality, reliable, and defect-free parts now at an even higher production level."
The CBF20 offers several enhancements in terms of processing efficiency and improved mold life, according to Rosati. The 20-station CBF unit went from a vacuum-fed material handling system to a gravity system for faster processing and reduced scrap.
Mold life was improved through extensive mold design engineering enhancements. Downstream operations such as vision inspection, leak detection, and plasma coating were also enhanced to match the increased production.
CBF is a breakthrough process which combines compression molding and blow molding. The material is extruded, cut, and precisely transferred into the compression cavity. A preform is produced and a pre-blow and full-blow process is completed in the same mold station with no transfer of the preform.
In addition, CBF has no manifold for melt distribution to individual separate cavities, which results in better quality parts because there are no temperature differences and less chance of resin burn and degradation. The process delivers less particulate contamination and due to the continuous extrusion process with simple melt channel, resin and color changes are also quicker.
The pre-blow process allows for effective separation of plastic from the compression core. This reduces the chance of plastic sticking to the metal core rod, resulting in more uniform wall thickness distribution.
Weight distribution is also better controlled with compression blow forming, said Amcor. The weight of the resin shot is controlled for all cavities with a servo-controlled melt pump, resulting in more accurate part weight distribution across all mold cavities. The process also operates at lower temperatures, which results in lower residual stress in the end product and cycle times which are reduced.
Energy consumption is reduced through lower process temperatures and application of updated machine process improvements. The process achieves thermodynamic stability quicker and makes production bottles within 10 minutes from machine start-up.