Needle valve
Valve gate technique with a four-fold clever solution for the needle motion.
High demands on surface finish appearance, reduced cycle times, lowest possible shear stress and large gate cross-sections. The correct answer to all these demands: valve gate technology.Individual nozzles with hydraulic actuation are approved up to 40 bar. In case of pneumatic actuation - depending on the system - pressures up to 10 bar may be required (however, at least 8 bar).
The cylinders are arranged externally. The new, innovative design of a contour-shaping guide insert and optimized needle valve permit contact-less and virtually wear-free sealing of the gate. The new GÜNTHER PM needle guide made from powder-metallurgical steel guarantees economical and virtually wear-free operation. During the closing motion of the needle, it is first centred by means of a conical guide, until the needle fully and precisely enters the cylindrical guide. Another advantage is the division of needle guide and nozzle tube - if required, the needle guide can be replaced without effort. Gate diameters from 0.8 mm to 5.0 mm can be selected. Standardized components result in length dimensions from 30 mm to 350 mm at material tube diameters from 3 mm to 16 mm. Up to 30% glass-filled plastics can be processed.
Replaceable Valve Pin Guides
Type LA
The needle is centred by means of a conical guide, until it fully and precisely enters the cylindrical guide (to the axis of the gate bore).
Advantages:
- Long service life, since virtually no wear
- Replaceable needle guide
- Needle guide immerses to the article and is contour-shaping
- Recommended for wearing materials
- By exchange of the PM pieces, the optimized shut-off needle can enlarge or reduce the gate Ø without reworking the mould nest. The exact needle guide achieves a virtually wear-free seal and a clean gate without burrs.
- Tightest tolerance between the needle guide and the gate.
Valve gate systems
Multiple applications in combination with conventionally heated manifolds with 230 Volt operating voltage are technically interesting, since valve gate nozzles can be designed from all standard nozzles. Smallest nozzle pitches from 8 mm can be achieved. These nozzles designed for 230 Volt operating voltage can be controlled individually and are suitable for processing of low-viscosity to reinforced technical plastics.
The needle motion can be achieved by
- single needle nozzle
- single valve gate
- lifting plate
- inclined plane
with pneumatic or hydraulic actuation.
Special through-holes in the tool clamping plate permit individual adjustment of the immersion depth of shut-off needles from the outside. The selection of the needle actuation depends on the application, space situation and the size of the tool.
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Seminars
