The main requirements in the segment of the silicone rubber processing (LSR) concern the total process automation, the absence of wastes, the total absence of burrs and the elimination of re-finishing machining. Demands that can be satisfied by an injection machine Engel e-victory 200H/80W/120 combi, equipped with integrated linear robot Engel viper. The solutions offered by Engel allow managing multi-component processes in safe and efficient way even when we are dealing with complex co-moulding of thermoplastic polymers and liquid LSR silicone.
To manufacture the casings of airflow measurement sensors with integrated seals, they first mould the thermoplastic techno-polymer sensor bodies, which are then transferred, by means of the integrated robot, into the 4 cavities where the LSR seal is over-moulded.
In the moulding of this special sensor, each seal weighs 0.04 grams and the total weight of each moulding is 0.16 grams. All this is possible thanks to the precision of the machine/mould pair and to a particular software developed and patented by Engel: the iQ weight control software that, applied to the moulding of plastics and of the LSR silicone, can detect even minimal variations of the silicone density by varying process parameters. The result is a constant waste-free production cycle.
In this particular application, the column-free technology of Engel e-victory presses offers a decisive contribution also for the process stability, since the closing group (equipped with the force-divider) applies the closing force uniformly on the mould, acting on the entire plan surface.