Vis
For many years, PMT has strived to combine Plastics, Mechanical Engineering and Metallurgy.
Manufacture of new injection or extrusion screws
At PMT, we design and manufacture new screws for small and medium-sized injection moulding and extrusion machines. Each screw is engineered to meet the specific requirements of your production process: from standard applications to the most complex technical specifications.
Depending on the processed material and its additives, we recommend a type of steel that will ensure the screw has an optimal service life. Among the steels on offer, you will find C14 steel, C11 steel, C6 steel and NITRU steel.
Processes used
Gas or ion nitriding
Gas nitriding of a screw is a thermochemical surface treatment designed to increase the hardness and wear resistance of the thread. This process involves diffusing nitrogen into the surface layer of the steel, without altering the core of the screw. It is particularly suitable for applications involving unloaded or low-abrasive materials. Gas nitriding helps to extend the component’s service life whilst maintaining good dimensional stability. The choice of this treatment depends on the type of steel, the material being processed and the operating conditions of the screw.
Vacuum hardening
Vacuum hardening is a heat treatment that increases the hardness and mechanical strength of a screw throughout its entire cross-section. Carried out in a controlled atmosphere, it ensures consistent properties whilst minimising oxidation and deformation. It is particularly suitable for screws subjected to high stresses or abrasive materials; the choice of treatment depends on the steel grade, the application and the process requirements.
Reloads
Thread peak re-coating is a repair process that involves applying a wear-resistant material to the areas of an injection or extrusion screw that are subject to the greatest stress. Carried out using a suitable welding process, it compensates for wear, restores functional clearances and extends the screw’s service life. This solution is ideal when wear is localised and the screw body remains in good condition; the choice of material depends on the operating conditions and the material being processed.
Other surface treatments
Depending on the materials processed and the conditions of use, various surface treatments can improve the screws’ resistance to wear or corrosion. Hard chrome plating increases surface hardness and reduces friction, whilst carbide spray coatings enhance abrasion resistance in harsh environments. Hard-wearing alloy overlays can also be applied locally. The choice of treatment depends on the application, the material and the required performance.
Possible Options
Pineapple
The pineapple mixer is a mixing element integrated into the screw, characterised by protrusions or ridges distributed across its surface. It enables the effective mixing of molten material, colourants and additives, in order to improve homogeneity prior to injection moulding or extrusion.
PMT chevrons
The chevron mixer is a mixing element integrated into the screw, designed to improve the homogenisation of the melt. It is used to achieve a more uniform distribution of colourants and additives, whilst maintaining process stability and the quality of the processed material.
Language barrier profile
The barrier profile is a screw geometry designed to separate solid material from molten material during plasticisation.
It serves to improve process stability, melt homogeneity and dosing consistency, particularly for demanding applications.
Maddock
The Maddock mixer is a mixing geometry integrated into the screw, used to improve the homogenisation of the melt.
It serves to refine the melt, distribute additives more evenly and stabilise the process prior to injection moulding or extrusion.
Repair of injection or extrusion screws
Thanks to its exceptional expertise, PMT can repair your screws and also modify them if necessary.
Possible corrections:
- Polishing
- Surface grinding
- Coupling repair
- Drive repair
- Valve removal or fixing
- Straightening
- Thread repair using TIG or PTA processes with: Stellite, Colmonoy, tool re-coating, etc.
- Material treatment
- Etc.
Permitted changes:
- Profile modification
- Add a mixer
- Etc...
Manufacture and repair of screws
PMT can quickly supply you with a new part for any plastics processing machine, across all brands: Arburg, Engel, Netstal, Haitian, KM, Battenfeld, Billion, Demag, Fanuc, Klockner, JSW, Sumitomo, etc.
These screws are designed and manufactured in PMT’s workshops and developed by our engineers. We can design these screws for all injection moulding machines on the market and supply them to you in any length, material, diameter and with specific options.
Please do not hesitate to contact us for a full quotation tailored to your requirements.
Our services
Repair service
Quick repairs to your screws, sleeves and valves to minimise machine downtime.
Find out more
Stock Management & Preventive Maintenance
Permanent stock of critical parts preventive checks to avoid breakdowns.
Find out more
Engineering Department and Bespoke Design
Adapting your equipment to new materials or specific production rates.
Find out more
Technical support
Expert support (by telephone and on-site) to optimise your settings and maintenance.
Find out moreWhen should you use PMT?
At PMT, we know that an unplanned shutdown or a shortage of parts can quickly prove costly. That is why we offer you access to our permanent stock, our express repair workshop and our technical expertise to support you on a day-to-day basis.
Your machine has stopped
We repair your screws, sleeves and valves quickly to get your production back up and running.
You’re missing a key component
Take advantage of our permanent stock, available within 48 hours.
You are preparing a new production
Our design office develops parts tailored to your materials and production rates.
Do you want to reduce your unplanned downtime?
A preventive maintenance programme and technical support to anticipate wear and tear on your equipment.
