Injection molding machine for high-performance injection PET preforms

In the middle of last year, Engel company took over the development and sales of PET preform injection molding machines from its long-term partner SIGCorpoplast, which has expanded Engel's machine types to cover a wide range of applications. These machines appear on the market under the name Engel MacPET and produce PET preforms for stretch blow molding of PET bottles.

At the heart of every MacPET preform high-performance injection molding system is a toggle closure machine for quick turnaround production. The injection side is equipped with a special pressure-retaining device. The specially developed pressure-retaining device for PET injection molding is Engel's PET plasticization device that is different from other manufacturers. During the pressure holding and cooling phases, it allows the melt to be metered for the next injection. Before the next injection, the remaining melt in the pressure-retaining device is completely discharged into the space in front of the screw and follows the first-in, first-out injection principle, which shortens the time for the thermal stress to act on the melt. The MacPET series machines consist of five types of machine with clamping force up to 5000kN, which are particularly suitable for applications in 12, 16, 24, 32, 48, 64, 72 or 96 cavity moulds.

At the same time, through the long-term cooperation between Engel and SIG Corpoplast, more than 100 such machines are operating reliably in 20 countries on all continents of the world. The 5 point double toggle lock cooperation together with the accumulator not only ensures the quick opening and closing of the mold, but also ensures the extreme rigidity of the clamping system and the gentle operation of the mold. When the mold is 96-cavity, the mold opening and closing time including the removal of all plastic parts is 2.8 seconds maximum. The energy-saving oil pressure system includes a servo-controlled progressive transmission pump for all screw movements, which makes economical operation of the machine possible. Energy consumption is reduced to a very small extent.