Valve gate nozzles: Valve gate nozzles guarantee consistent sprue quality
The GÜNTHER portfolio includes a multitude of valve gate nozzles and needle actuation options. This enables both a technically and financially perfect adaptation to a wide variety of different hot runner applications and mould concepts. Both the smallest and large shot volumes and sprue mark cross-sections from 0.8 to 4.0 mm (in the standard) can be reliably implemented with valve gate technology. Depending on the application, up to 50% filled plastics can be processed.
The advantages at a glace
- Time and cost savings thanks to easy maintenance
- Needle guide and needle changing without removing the mould
- No reworking of the mould inserts required in case of injection point bore wear
- Long service life of the needle guide, resulting in minimal downtimes and attractive cost savings.
- Consistent sprue quality across a longer period of time, including for filled plastics.
- Material changes can be easily responded to thanks to straightforward gate adaptation.
- Unambiguous opening behaviour
- Sequential injection and cascade injection moulding possible
The innovative design of the needle guide and the optimised valve needle enable extremely low-wear operation. During the shut-off movement, the needle is first led over a cone up to the cylindrical pre-centring device for precise immersion into the cylindrical injection point. The needle guide is supported floating in the material pipe.
The LA needle guide type is immersed up to the item and provides contour. The LAZ needle guide has a tapered shape with a smaller contact surface which creates a smaller impression. This version is suitable for items with a minimal wall thickness and item contours not permitting a larger impression. The KA valve gate type is used where a second marking on the item is not permissible. The needle is guided close to the sprue in the material pipe.
Should maintenance be required, the needle guide can be changed with minimal effort. Openings in the mould clamping plate enable the immersion depth of the shut-off needles to be adjusted from the outside.