Barrels

Extruder and injection moulding barrels

We manufacture new barrels as direct replacements for your OEM parts, refurbish and re-sleeve worn ones, and manufacture feed liners and housings for the plastics, rubber and feed industries.

Call +44 (0) 1706 655402 Send an enquiry

Vented extrusion barrel on stands with its screw — **FIG. 01** · Vented barrelTWS

Manufacture

Barrel manufacture

We manufacture new extruder and injection moulding barrels from 18 mm to 450 mm bore diameter and over 6 metres long. You can choose nitrided EN41B steel or a bimetallic bore.

Nitrided barrels suit general-purpose work and can have any bore size. We gas or plasma nitride them to a depth of at least 0.6 mm and a hardness of about 65–70 HRC.

Bimetallic barrels suit high-wear and corrosive applications. The lining is centrifugally cast into the barrel blank at over 1100°C, then honed to size. It’s at least 1.5 mm thick, and usually 2–2.5 mm. Linings range from a standard grade for lightly filled materials up to grades with maximum abrasion and corrosion resistance.

Barrel and feedscrew laid on protective cloth — **FIG. 02** · Barrel & screwTWS

Refurbishment

Barrel refurbishment

In most cases, we refurbish a worn extruder barrel by honing it parallel and oversize to remove the wear. We then refurbish the screw to suit the new bore, which brings the clearance back to its original standard. It’s one of the most cost-effective ways to extend the life of a screw and barrel. EN41B barrels are re-nitrided to their original hardness. Bimetallic barrels keep their hardness, so they don’t need it. We refurbish barrels from 25 mm to 250 mm diameter and over 6 metres long. If a barrel is too worn to hone, we’ll manufacture you a new one. For injection moulding barrels, a short re-sleeve is usually the best route (see below).

Rubber barrels can usually be refurbished the same way, though some have liners that need replacing. For cereal and pet food lines, we manufacture and refurbish spiral and straight fluted segmented barrels in all sizes, and mild steel or stainless steel trough-type transfer barrels. We also manufacture new single and twin screw liners and twin screw modules.

Barrel feed throat section in the workshop — **FIG. 03** · Feed throatTWS

Re-sleeves

Barrel re-sleeves

The injection stroke often wears the exit end of an injection moulding barrel. We don’t replace the whole barrel. Instead, we bore out the worn end and fit a short new section, up to five times the bore diameter long. It’s most common on injection barrels, but it works on other types too. We re-sleeve in:

Nitrided EN41B
Bimetallic
H13 through-hardened tool steel

Feed liners

Grooved and plain feed liners

We manufacture grooved and plain feed liners as direct replacements for the OEM part. Grooved liners are generally nitrided, with straight or spiral grooves. Plain liners can be bimetallic for a longer life. Like any part in contact with plastic or rubber, liners wear, and a worn liner can badly hold back your extruder’s performance.

We also manufacture complete feed housings, with or without water cooling, and re-sleeve feed housings. If your liner forms the water seal, we can redesign the housing with its own sealed water chamber, so you can change the liner at your factory. If the water channels have blocked over time, we can often remove the water jacket, clear the channels and refit it.