New Screws & Barrels, whether for injection moulding or extrusion based processes, can be produced from existing drawings or by using sample components. Prices are usually more competitive than those of the OEM’s, and it is sometimes possible to improve design in terms of durability, and/or the ability to process a specific material type.
For example, some OEM’s supply machines with Nitrided barrels fitted. Although the internal bore is extremely hard wearing, the layer of hardened material is also extremely thin. By contrast, the Bi-metallic barrels available from our UK based specialists have a much thicker layer of hardened material, and offer a considerably longer and more consistent service life.
Refurbishment of Screws & Barrels relies on the refurbishment provider retaining the components for a more extended period of time, but costs will be lower.
In the case of Screws, worn areas of the flights and/or mixing sections are removed and replaced, usually with a material that will provide superior wear characteristics to the original item when new.
Nitrided barrels can sometimes be ‘honed’ and re-hardened, the screw being refurbished so as to match the slightly larger barrel I.D. Alternatively, if wear is predominantly at the 'output' end of the barrel, a 'pocket' can be created, and a Bi-metallic sleeve inserted.