The screw tip assembly or non-return valve is crucial in ensuring a constant melt cushion giving you a repeatable, high quality finished moulding.
There is no such thing as a badly designed screw tip assembly, just whether it is the right or wrong design for your application. Ensuring slow wear (erosion) and accurate repeatability is the aim of the 'good' screw tip assembly.
The majority of moulders use the standard 3 piece assembly, the screw tip, the check ring and the spacer. Normally delivered as standard with new machinery, the OEM's have usually undertaken extensive testing to tweak their designs, in order to offer customers a very good general purpose assembly which can be used across a range of basic material.
We hold large stocks for many of the most popular German machines as well as Fanuc machines, but can also make non-stock items with a fast turn around.
In many cases we can make a new design for your application which can be based around other screw tip styles specifically designed for processing different types of polymers.
HIP Power metallurgy steels
All standard screw tips through hard and plasma nitride
Minimum High Wear 'As Standard'
As standard all our screw tips (none return valves) are made from a D1 material through hardened and then finished with a plasma nitride. To further improve the life of our screw tips all units over 45mm have special hard wearing pads fitted to the back of the flights as standard.
The Right Design For Your Application
Most new machines from the manufacture come with standard three piece General Purpose screw tip assemblies. Many other designs are available for processing specif materials. Look at our designs here
HIPS Power Metallurgy Steels
We supply HIPS (Power Metallurgy Steel) CPM9V and 440C for the ultimate corrosions and abrasion protection.
Extensive Stocks Ready To Ship
As standard all our screw tips (non-return valves) are made from a D1 material which is through hardened and then finished with a plasma nitride. To further improve the life of our screw tips all units over 45mm have special hard wearing pads fitted as standard to the back of the flights.
For many customers and competitors our standard quality would be referred to as a high wear option, or would be described generically as a bimetallic unit.
Buy no screw tips until you contact Invotec - 1000's of popular sizes from stock
Injection moulding screws for Arburg, Dr Boy, Billion (SAS), Demag, Engel, Ferromatik Milacron, Klockner, Krauss Maffei, Fanuc, Stork Plastics Machinery, Sandretto, Negri Bossi and many more injection screws for popular model moulding machines.
Need help? Contact us
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