Euro-Stel supplies all kinds of non-return valves for any type of injection-moulding machine and screw. Similar to screws and barrels, the choice of the proper metal and the thermal treatment for the non-return valve are highly important. A perfect geometrical design provides the valve with an accurate and smooth functioning as well as a long life.
There are four different types of non-return valves, with multiple variants:
The choice of the appropriate non-return valve depends on a number of elements, such as the type of plastics to be treated, the required dosing accuracy and the resistance to wear. Finally, the price matters too. Ball valves are more accurate than all other kinds of valves, but as they require more manufacturing processes, they are more expensive as well.
3-part non-return valve with loose ring
The 3-part non-return valve is the most popular type of valve. The valve
consists of a winged centre, a ring and a seat. With respect to the manufacturing
technology, this is a rather simple type of valve, which explains its
relatively low price.
Ball valves have a highly accurate shot precision and repeatability.
This accuracy is due to the high pressure sensitivity and the reaction
speed of the ball integrated in the valve. Our valves are internally and
externally reinforced with special steel alloys and then receive a thermal
3-part non-return valve with rotating ring
This type of non-return valve is easier to manufacture and has a relatively good injection characteristic. Because of the co-rotation of the ring with the screw, some important rules must be observed when using this kind of valves. Good heating conditions and a good condition of the barrel are very important to avoid damage on the ring.
Special valves for special applications and valves with mixing function
Euro-Stel also supplies some special non-return valves for the processing
of e.g. thinly liquid materials, highly transparant PC, glass fiber filled
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