The rigid plastics division of Australian manufacturer Amcor (Abbotsford; www.amcor.com) and compression moulding equipment manufacturer Sacmi Group (Imola / Italy; www.sacmi.com) have jointly commercialised what they claim to be the industry’s first compression blow forming (CBF) machine for the production of rigid HDPE pharmaceutical bottles. The companies said the process, which combines compression moulding and blow moulding, has significant advantages over conventional processes, providing improved quality and productivity, sustainability benefits, and the potential for lightweighting.

Amcor collaborated with Sacmi – the original developer of the process – in a 14-month project to adapt the technology for pharmaceutical packaging. The two companies focused primarily on optimisation and enhancement of process control to meet the requirements of pharmaceutical manufacturers. Amcor has an exclusive arrangement with Sacmi to utilise the technology in select market segments and global regions. The company has already commissioned a 12-cavity platform (CBF-12) and is producing HDPE over-the-counter and prescription bottles at its Youngsville, North Carolina / USA facility. Three additional machines are on order and will be in production by the end of the year.

Bob Israni, Amcor’s technical manager for the pharmaceutical market, said: “Compression blow forming is the most advanced processing system for the production of pharmaceutical containers, delivering high-quality, reliable, and defect-free parts.” The CBF process expands Amcor’s pharmaceutical bottle manufacturing platform and represents a major improvement over conventional technologies, the companies said.

In compression blow forming, material is extruded, cut, and transferred into the compression cavity. A preform is produced and a pre-blow and full-blow process is completed in the same mould station with no transfer of the preform. Compression blow forming has no manifold for melt distribution to individual separate cavities, resulting in better quality parts as there are no temperature differences and less chance of resin burn and degradation, the companies said. Weight distribution is also better controlled with the weight of the resin shot controlled for all cavities with a servo-controlled melt pump, resulting in more accurate part weight distribution across all mould cavities. The process also operates at lower temperatures, which results in lower residual stress in the end product and reduced cycle times.

“The company sees a ‘range of applicability’ for CBF and will selectively invest with customers in high-volume, long-term projects,” according to Tod Eberle, Amcor Rigid Plastics’ vice president for quality and engineering. In addition to the 12-cavity unit already in production, Amcor has committed to additional CBF systems, including a 20 cavity unit that will be in production by the end of 2012 with the capability for production of HDPE, PP, and PET pharmaceutical containers.

Along with pharmaceutical packaging, Amcor and Sacmi envision strong potential for CBF in other markets, including single-serve dairy packaging made of HDPE for applications such as liquid yogurt and probiotics.