TECHNICAL WINDOW
01/2014

SIPA brings the X factor to preform lightweighting with XMOULD

SIPA has just launched a highly innovative preform mold technology that enables processors to fill wall sections that are thinner than ever before. XMOULD gives designers the power to create preforms that are longer or wider, for the creation of containers with more suitable stretch ratios. It is now possible, for example, to design a 500-mL bottle preform weighing as little as 7.2 g that presents no production issues, either during injection molding of the preform itself or when it is stretch-blow molded—and which can be processed on existing equipment.

Low weight, high performance

Even though the preforms made on molds incorporating XMOULD technology are extremely light, the high mechanical performance required in the finished bottle is not compromised. The new preform designs save on energy as well as material, so carbon footprints along the production and supply chain are smaller than ever.
XMOULD technology now makes it possible to produce preforms with ratios of length to wall thickness (L/t) close to 60, while applying injection pressure similar to that normally used for preforms with 45 L/t ratios. This means that the stretch ratio in the final 7.2 g bottle is between 10.5 and 13.6, depending on its design—highly manageable for modern stretch-blow moulding equipment. Plus, the performance of the bottle, on the filling line and in use, meets all relevant requirements.

Pushing back the boundaries

"With XMOULD technology, we are pushing back the boundaries in PET preform injection moulding," says Laurent Sigler, SIPA’s Innovation Director. "When it comes to L/t limits, 50 has been the magic number for more than 20 years, so taking it up to close to 60 in one step is a major achievement. XMOULD is making new preform design opportunities available, and our customers can lightweight their preforms even more and/or further improve their bottle performance.
“I know that a lot of people are going to be asking what XMOULD technology is. Right now, all I can say publicly is that it has to do with making surfaces smoother—and that it works!”

Technology is available to all

The advantages of XMOULD technology are being made available across the market. Injection moulding of the new preform designs can be carried out, not only on SIPA’s XFORM new generation of processing equipment, but also on most existing preform injection moulding machines, regardless of their brand. Similarly, the preforms can be blown not only on SIPA linear and rotary stretch-blow lines, but also on lines from other suppliers.