Technical Welding Services
Contact: Jim Sutton
Corporation Rd
Sparth Bottoms
Rochdale, Lancashire 0L11 4HJ
UK
Phone: 01706 655402
Fax: 01706 657735
TWS has spent the last 20 years developing and testing welding procedures for refurbishing single, twin flighted, barrier flighted and twin screws for the plastics, rubber and feed industries. We can refurbish screws made from unusual alloys i.e. Hastelloy C, which is used with very corrosive materials used in electrical cables etc.
In 1995 TWS moved to purpose built premises in a central location of Rochdale near to the M62 motorway network. Anybody wishing to visit our premises will be made very welcome.
TWS has a vast experience of the refurbishment of extruder screws and barrels in three major industries:
* The Plastics Industries
* The Rubber Industries
* The Cereal and Pet Food Industries
Industry
TWS has a vast experience of the refurbishment of extruder screws and barrels in three major industries:
The Plastic Industry
TWS can refurbish any screw From small injection moulding screws, barrier screws, twin screws through to lager screws used in the reclamation of scrap material.
The Rubber Industry
TWS can refurbish most types of mixing rotors through to large dump screws.
The Cereal and pet food Industries
TWS can refurbish solid one piece screws through to segmented screws and we have a vast knowledge of clextral, wenger and sprout screws and barrels.
The Plastics Industries
TWS can refurbish single and twin screws of any, size (up to 600mm dia.), pitch or configuration (maximum length 6000mm). This includes injection moulding, blown film, compounding screws either with a single/barrier/twin flight with or with out mixing pegs/madox section.
Barrels:
TWS can in most cases refurbish worn extruder barrels by honing parallel and re Nitriding and then re-furbishing the screw to suit the new barrel size. If the barrel is too worn to hone out, TWS can manufacture new barrels to be a direct replacement in either Nitriding steel (EN41b) or with a bimetallic bore (recommended for highly corrosive and abrasive materials).
The Rubber Industries
TWS can refurbish all types of mixing rotors from the smaller cm sizes through to the larger Banbury type. We also refurbish twin start inter channel extruder screws used in the rubber industry right through to the larger dump screws up to a maximum of about 18".
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The two pictures above are showing before and after refurbishment of a 18" x 15" dump screw. This screw was fully refurbished with grade 1 stellite, it was also de-chromed and fully re-chromed to the customers requirements.
2 off BR rotors before and after refurbishing they where welded from end to end in mild steel and re-ground to size and then re-chromed.
These two pictures show from start to finish of a fabricated extruder screw for the rubber industry. This screw is a 14" to 12" tapered dump screw and was fabricated from EN19. it was fabricated (rather than machined from a solid piece) in this way to cut cost and machining time and proved to be very successfull. Since this prototype we have done several more including one that was 6000 mm long and 12" in dia and is now successfully working in the rubber industry in america.
The Cereal and Pet Food Industries
TWS has vast experience and knowledge of clextral, wenger and sprout matador screws and barrels and can refurbish solid one-piece screws, segmented single screw elements and twin screw elements.
TRANSFER SCREWS:
TWS can refurbish and manufacture mild and stainless steel transfer screws used in the food industry.
AIR LOCKS:
All types and sizes of air locks can be refurbished from just re-manufacturing the internal paddle (i.e. welding and re-machining the tips using stellite, welding and re-machining the journals and fitting new bearings and oil seals). The housing can also be refurbished by de-chroming, repairing and re-chroming to original size.
BARRELS:
For the cereal and pet food industriesTWS can refurbish and manufacture most types of barrels for the feed industries including:
* Spiral and straight fluted segmented barrels all sizes. (New/refurbished)
* Single and twin screw liners. (New)
* Twin screw modules. (New/refurbished)
* Mild steel/stainless steel trough type transfer barrels. (New/refurbished)
Screws - New
TWS can manufacture new screws and segments to be a direct replacement for your old worn out parts to minimise on down time. Then we can refurbish your old screw to a like new condition and therefore giving you a spare screw/segment to rotate between production and refurbishment (saving money and down time).
Fabrication
TWS has an extensive fabrication section in which we can fabricate in mild and stainless steel up to a capacity of 3.5 tonnes. We have an experienced fabrication department, which can fabricate anything from a small bracket up to a feed throat weighing 3 tonnes used in the rubber industry, also water baths, stillages, frame works and mezzanine floors etc. We also have done several large contracts for local councils in our area, from supplying and fitting steel staircases/fire escapes to steel railings and gates on housing estates and local schools. We can also supply and fit bespoke wrought iron railings and gates for industrial, commercial, and private dwellings.
This picture shows 3 of 5 Window Frames fabricated for the Nuclear Fuel industry. These fabrications weighed approximately 2.2 tonnes each and are made from 60 mm mild steel plate with a stainless steel flared flange welded on one end. All the welding on the window frames had to be done to ASME IX codings. TWS currently has welders coded to ASME IX and BSEN 287.
\This picture shows a Feed throat fabricated for the rubber industry, we also manufactured the barrel to suit the feed throat. The feed throat and barrel both had water cooling jackets round the main body
Repair Service
TWS also offer a breakdown service where we can do part repairs to your damaged screws and barrels i.e.
* Bent screws (straightened)
* Damaged flights (repaired like new)
* Screw tips sized (removal and refitting)
* Screw tips snapped (in most cases we can remove the broken stud ready for fitting a new tip)
TWS has an extensive range of machining facilities and can repair all sorts of worn out parts from a bearing journal on a small shaft to a larger 3 tonne roller used in the paper industry.
We also carry out a screw polishing service, which in our opinion is second to none and in many cases screws will be returned polished to a higher standard than when new.
TWS has also got a pressing facility of a 100 tonnes mainly used to press liners out of housings and screw segments of shafts. But also comes in very handy for pressing seized screws out of barrels.
Standard Refurbishment of Screws
The standard refurbishment procedure listed below is for a single flighted standard extruder screw, and some procedures may differ on different types of screws.
1. Clean screw to remove all products.
2. Straighten screw prior to initial grind.
3. Grind screw on flight tips to remove all wear and damage, and establish a clean diameter (this provides the basic surface for rebuilding the screw flight).
4. Repair all screw damage (i.e. Damaged and chipped flights, root damage etc).
5. Weld buttering layer if required (the buttering layer is used to prevent the hard surface of the flight cracking due to different thermal expansion between the base material and the hardfacing weld).
6. Grind the buttering layer (to achieve a nominal thickness of hardfacing material on the crest of the flight).
7. Preheat the screw for welding.
8. Post heat the screw after welding and allow the screw to cool slowly.
9. Straighten screw prior to grinding.
10. Grind flight tips to final dia plus 0.030".
11. Initial side grinding and polishing of screw.
12. Apply surface coating or treatment as required (i.e. Re-nitriding etc).
13. Final grind of flight tips to give recommended radial clearance.
14. Final polish of completed screw.
15. Final inspection.
16. Pack ready for dispatch.
