PETpla.net Insider 09 / 2011

PREFORM PRODUCTION 20 PET planet insider Vol. 12 No. 09/11 www.petpla.net MHT’s upgrade sets offer outputs one-third higher – on existing machines More bang for your buck* Productivity, sustainability and conservation of resources are key issues in the production of PET bottles, so who would say no to the equivalent of getting 33% more mileage from a tank of petrol in their current car? MHT Mold & Hotrunner Technology AG (Germany) says that its upgrade sets enable preform manufacturers using Husky HyPET 300 or 400 injec- tion moulding machines to produce one-third more preforms from their existing equipment. turer in South America. The (approxi- mately) 85mm long, 15g preform with a PCO 1881 thread is created in a cycle time of 9.0s. The control unit of the Husky HyPET 300 is designed for a maxi- mum of 72 cavities and the upgrade adapts to it, so the injection mould- ing machine can continue to operate the mould. There are two options for nozzle control. Nozzles of the same thermal type are either combined, so that the machine still has a total of 72 regular positions, or an external device can assume control of all 96 nozzles. The upgrade set for HyPET 400 works in a similar manner. The second option offers customers the opportunity of running the machine in so-called single-nozzle regular opera- tion, which means that the mould is equipped with nozzle thermal sensors. In operation, temperature is constantly monitored and regulated at each indi- vidual cavity. When preforms are produced, they need to be post-cooled in order to be dimensionally stable for further handling as bulk material. For this pur- pose, MHT has developed MHTcool- Max, a three-stage-post-mould cool- ing solution. An international patent has been applied for. MHT has developed upgrade sets that take 72-cavity machines to 96, and 96 to 128. The company says that the sets improve effectiveness, have higher cooling and energy efficiency and enable companies to get higher output from existing machines, eco- nomically and ecologically. It does this by moving the cavities slightly closer together and adding additional rows to the left and right. The MHT team has achieved higher cavitation without making the moulds much wider. The stacks, i.e. the moulds in which the preforms are created, are identical to those of the long-established 72-cavity mould technology. This space saving does not require or imply a ‘filigree’ mode of construction, which may be more susceptible to faults. A pilot project is currently running successfully with a leading preform and bottle manufac- MHT has achieved higher cavitation without making the moulds much wider. Cooling pins *based on an article by Sabine Kob, MHT