he injection moulding machines still maintain their features of solidity and compactness, features that are peculiar to NPM`s way of producing, and that are based on the five points reliable toggle in fusion and bronze bushes and on the pump with variable capacity and radial piston.
Cast platens assure high structural rigidity and allow for good-sized guides on tie bars. The moving platen, supported by sliding blocks, makes it possible to use the heaviest moulds, maintaining maximum parallelism and precision on movement.
Adjustment of mould thickness is effected via a hydraulic motor with central crown gear transmission. Other features include:
- automatic programmable multiple point lubrication and oil recovery,
- control of clamping and opening movements with fully programmable speed and pressure profiles actuated through a proportional distributor,
- position detection by means of absolute linear transducer, and software computation of the various speed ramp values to allow for fast and precise movements that protect and safeguard the mould.
The hydraulic plate ejector is integrated into the rear portion of the moving platen, and allows precision movements even in the presence of unbalanced loads, thanks to the specially sized guides.
There are independent speed, pressure and position values for the ejection and retraction movements and for the different ejection cycles. The rational integration of peripherals in the mould area is assured by a particularly unencumbered drop-out area, accessible on three sides.
The movement of the unit and the injection phase are actuated using two hydraulic cylinders for each movement. That assures both a perfect alignment of the injection unit with the mould, and the subsequent balanced application of injection force, while also leaving sufficient clearance around the plasticising screw to facilitate routine and special maintenance actions.