Husky, Sacmi, KraussMaffei, Netstal, SIPA and many others: Every machine type represents its own special challenges for the injection mold and the post mold cooling (PMC) unit. To achieve the fastest cycle times, the preforms are removed while the plastic liner, i.e. the material between the solidified exterior walls, is still flowable. This is done either by the PMC unit itself, but sometimes also through the use of a transfer plate that transfers the preforms to the PMC section. This is where the preforms are made dimensionally stable and then ejected. The PMC units are built in multiple stages, so that production steps can run in parallel, thus saving time. Only with an optimally coordinated PMC section can modern high-speed machines make full use of their capacity and produce preforms in perfect quality.
As one of just a few independent providers, MHT produces PMC solutions with three or more stages for all machine types – and with some, even significantly shorter cycle times are possible than with the original equipment, thanks to the patented MHTcoolMAX technology. With MHTcoolMAX, the cooling not only takes place through the outer shell, but also on the inside, with a cooling mandrel. The air flow is conducted to the thread and the preform body, where the temperature then drops significantly faster. This is especially important for wall thicknesses >2 mm or challenging thread geometries. For high preform weights, there is a wear-free extraction mandrel and an optional spring mechanism. Thanks to its many years of experience with all PET systems, MHT is also an expert in the area of post mold cooling, and customers can benefit from this knowledge.