TPT November 2008

T ube E xtrusion & D rawing T echnology

E ven exclusive of the multitude of polymers that can be extruded into plastic tubing, and of the remarkable

‘pultrusion’ process for the production of fibre- reinforced tubes, extrusion technology is versatile to an extraordinary degree. Tubing may be extruded from aluminium, copper, lead and tin, magnesium, zinc, plain carbon and stainless steel – even titanium. Magnesium is approximately as extrudable as aluminium for tubing in avionic and nuclear applications. Molten lead may be used in place of billets on vertical extrusion presses.

 The foam-core pipehead series, from KraussMaffei Berstorff, includes two twin-screw extruders (see page 68)

Hot extrusion or cold extrusion? Either method yields superb results; and the products are readily mass-produced and cut to length, economical, and lightweight. Tube extrusion does it all. And tube drawing does the rest, also supremely well: sizing and re-sizing, reducing, changing inside and outside diameters and wall thicknesses, satisfying custom requirements for close

dimensional control and smooth and ultraclean surfaces. Drawing is the method of choice for refinement of the grain structure and enhancement of the finish. Tube extrusion or tube drawing? To judge from the performance history of these highly evolved companion processes – as complementary as any in the tube making business – the probability of satisfaction is excellent with both.

 Battenfeld supply large-diameter pipe extrusion lines up to 2,000mm in diameter (see page 70)

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N ovember 2008

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