Injection Molding: PET Preform Molding Machine Switches to Side Entry

KraussMaffei HighPerformance AG’s Netstal brand has introduced the new PET-LINE of preform injection molding machines, featuring lateral removal of preforms in a design the company says is fully compatible with existing side-entry molds and after-cooling stations.

Other highlights for the new PET-LINE include higher output, energy efficiency, greater ability to run recycled PET and a new control. In a release, KraussMaffei said the PET-LINE positions its Netstal brand as an alternative for molders whose production layout currently utilizes machines with lateral removal and who have a corresponding stock of injection molds, noting the new line can be paired with legacy side-entry molds and associated post-mold cooling stations. KraussMaffei also said its existing Netstal PET-LINE with top entry is still available giving its customers the option for side and top entry.

The new series launches with a machine providing clamping force of 4,000 kN (400 tons) and a 6000 injection unit with the ability to run molds with up to 128 cavities. KraussMaffei notes that more models will be released in coming years to support production of all common beverage applications. A company spokesperson told Plastics Technology that eventually the range will cover preform cavitation from 48 to 144, with some special preform designs below 48.

The machine was optimized for processing of recycled PET (rPET), including a new screw design and two-stage injection unit. The KraussMaffei spokesperson said the new PET-LINE will feature a barrier screw optimized for running PET. The two “stages” of the injection unit, include the plasticizing unit with barrier screw and a second stage with a shooting pot where melt is transferred from the plasticizing unit and injected into the mold. Accumulators are used for the hydraulic circuit. The company says the new design makes processing of up to 100% rPET material is possible.

The PET-LINE features a 5-point dual toggle lever in its fully electric clamping unit. Lock-to-lock time comes in at 1.9 seconds for the 400-ton machine, shortening cycle times and boosting output. The machine be equipped with up to four post-mold cooling stations, with interior and exterior cooling ensuring more uniform preforms.

The PET-LINE also marks the debut on the newest control technology for Netstal—aXos 9. KraussMaffei says this new control emphasizes user friendliness with a new operator panel comprised of a central touchscreen flanked by haptic keys. Navigation occurs exclusively via the touchscreen, while all axial motion is triggered via the haptic keys. The company believes operators will appreciate the advantage over pure touchscreen controlling, noting that the distinct feedback from the haptic keys simplifies “blind” operation with regard to the moving axes.

In lieu of a planned launch event derailed by the coronavirus pandemic, KraussMaffei has organized exclusive presentations at Netstal’s headquarters in Näfels, Switzerland and digital visits for all those customers who are unable to travel. This hybrid event will run over three months, with interested customers able to sign up for exclusive presentations in Näfels or attend online meetings where the demonstration of a running machine can take place.