Munich, October 15, 2008 - At the Fakuma 2008 in Friedrichshafen (October 14-18), KraussMaffei will be demonstrating an innovative manufacturing cell which produces a thermoplastic lid and immediately applies a PUR gasket to it. The cell uses a PUR high-pressure process which allows the gasket to be applied immediately following injection moulding, without temporary buffering. This fully-automated system is very compact and highly productive. Sonderhoff, KraussMaffei's innovative partner, developed the PUR sealing system for this high-pressure application.
KraussMaffei supplied the complete manufacturing cell as a single-vendor solution. This ensures that the individual components - injection moulding machine, industrial robot and PUR metering system - work perfectly together. This benefits customers in many ways, including the fact that there are absolutely no interfacing problems.
At the Fakuma, the cell will be producing lids made of glassfibre-reinforced PP for use in vehicle engine compartments. An IR 200 F/M industrial robot picks the parts out of the CX 160-750 ClassiX injection moulding machine and transfers them for surface treatment with atmospheric plasma. The Openair plasma technology from Plasmatreat, Steinhagen, ensures good adhesion between the PUR sealing gasket and the thermoplastic part. Immediately following surface treatment, the gasket is applied to the lid from a MK 3,5/5-ULP2K-VV mixing head. The groove that takes the seal is around 900 mm long; cycle time is around 30 s.
The mixing head is supplied by a TwinComet PUR metering machine, capable of achieving pressures up to 200 bar. The two PUR components are metered by two electrically-driven pistons operating anticyclically to generate a continuous flow of material at rates between 0.2 and 20 g/s. Continuous, high-precision metering produces a premium-quality PUR seal.
High productivity thanks to a fast-curing PUR system
High-pressure technology has the advantage that very fast-curing PUR systems can be processed. Moreover, high-pressure mixing heads completely dispense with a cleaning cycle, because they clean themselves after every shot. This compares favourably with low-pressure processes, where production must be interrupted at regular intervals to clean the mixing head. Cleaning also generates costs - through increased material consumption and waste disposal. In a high-pressure process, no PUR waste is generated; all the mixed material is used for the sealing application.
The IR 200 F/M industrial robot has an operator interface, developed by KraussMaffei Automation, which makes it a simple matter to perform all functions, including program selection, optimization and diagnosis. This highly dynamic, high-precision robot is ideal for creating the PUR seal, where it is essential to follow the prescribed contours exactly.
The plasticizing unit of the CX 160-750 ClassiX injection moulding machine produces an outstandingly homogenous melt, guaranteeing consistent product quality. Even processing glassfibre-reinforced thermoplastics, the screws and barrels have long service lives. The mould used at the Fakuma requires an installation height of 650 mm - including the hot runner system and the ejector. The two-platen engineering of KraussMaffei's CX machines, which makes it easier to accommodate very large moulds like this one, comes into its own with this type of application.
Applying the gasket with a MK 3,5/5-ULP2K-VV mixing head
Complete manufacturing cell as a single-vendor solution