Cast & Blown Film plastic extrusion companies.
Blown Film is produced by extruding plastic through a circular die and the inflating and cooling it internally with air. Once cool, the tube of plastic is collapsed and either split into two flat film sheets, (e.g. for stretch or shrink film), or converted into items such as bags by sealing across the width and perforating to allow for easy separation.
Cast Film is produced by extruding plastic through a slit type die, before passing it through a series of cooled rollers to produce the required thickness and properties. Thicker wall sections can be produced than with blown film, and the plastic is optically clearer. Typical applications are for food and textile packaging.
Pipe, Profile & Sheet Extrusion companies.
Plastic granules are converted into molten polymer, which is the forced through a metal die that contains the cross section of the profile of the extrusion required. This could be anything from a flat sheet to a tube or pipe, or a complex shape such as those used in the manufacture of uPVC windows. It is also possible to co-extrude a second material that is bonded to the primary product. For example a rigid plastic profile might be combined with a flexible plastic sealing strip.
'Take off rollers' then pull the still hot extruded profile through a long 'water bath', before the cooled product is cut into the required length.
In compounding, various materials are combined and melted, generally using an extruder of some type, the resulting material blend being then passed through a die to form long filaments of plastic that are then pelletized. In this way, a bespoke formula can be produced, this usually consisting of one or two primary material grades in combination with additives that enhance the appearance and/or processing properties and/or post processing characteristics of the final product.
Machinery & Equipment Suppliers
In addition to plastic extruders of various types, the main variants being single screw, twin parallel screw and twin conical screw extruders, there is also a large variety of 'down-stream' equipment available. Working forward from the output end of the extruder, there can be a co-extruder (simultaneously produces a second material that is combined with the primary extrusion), calibration/sizing section, water (cooling) bath, take /pull off section that typically uses rollers to control the movement of the extruded material through the process, length cutting, coiling or pelletizing station (sometimes the plastic is also reheated prior to cutting), and finally a handling/packaging station.
Other 'ancillary' items can include stations for applying backing tape, printing the extrusion or even punching holes.
This section provides details of specialist engineering services relating to extrusion equipment. This can involve inspection, maintenance, repair, and bespoke machinery refurbishment and development.
Screw & Barrel Manufacturers
New Screws & Barrels for 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 Services – Screws & Barrels
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.
Used Extrusion Equipment & Machinery
This section provides details of pre-owned or surplus extrusion and down-stream equipment that is currently available to buy in the UK. The equipment may be located at a UK processing company (in which case you may be able to view it in production), or at the premises of a UK based OEM or subsidiary.