Sheaths

PMT manufactures barrels for all types of injection moulding and extrusion machines.

Manufacture of new injection-moulded or extruded sleeves

Developed by PMT over 25 years ago, the Trimétal sleeve is a tried-and-tested solution for injection moulding and extrusion. Its three-part design helps to reduce press downtime and minimise maintenance costs through the simple replacement of the inner sleeve.

PMT also manufactures new liners, either adapted to manufacturers’ models or custom-designed by our design office.

The steels available include nitrided liners for non-aggressive materials, hardened steel inner liners, and bimetallic liners suitable for all materials, with the option of internal grinding or repair.

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.

Repair of injection or extrusion sleeves

Thanks to its exceptional expertise, PMT can repair your sleeves and also modify them if necessary.

Regrinding:

  • The sleeve is re-bored to the maximum wear dimension and re-nitrided if necessary.

  • The diameter of the screw, the valve and the nose is readjusted to the new diameter of the sleeve.

Partial lining:

  • The sleeve is lined over the length of the valve’s maximum stroke.

  • The liner is hardened to 56–58 HRC.

Trimetal refurbishment:

  • The first refurbishment transforms the worn sleeve into a PMT trimetal sleeve: the rear section is retained, whilst the front section and the hardened inner liner are new.

  • The second refurbishment involves replacing only the inner liner.

Before the screw-on sleeve:

  • The sleeve consists of two parts: a reused rear section and a new front section.

  • The front section is made of nitrided steel or bimetal.

Manufacture and repair of sheaths

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 sleeves are designed and manufactured in PMT’s workshops and developed by our engineers. We can design these sleeves 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.

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Stock Management & Preventive Maintenance

Permanent stock of critical parts preventive checks to avoid breakdowns.

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Engineering Department and Bespoke Design

Adapting your equipment to new materials or specific production rates.

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Technical support

Expert support (by telephone and on-site) to optimise your settings and maintenance.

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When 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.

Contact our experts
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.