K 2013: EXTRUDEX offers extrusion lines for multi-layer pipes and medical devices

Visitors to K 2013 will obtain information about high-end EXTRUDEX extrusion technologies in Hall 16, Stand B 42. In particular, the control unit VR-3, producing automatically a consistent vacuum in the calibration bath of an extrusion line, is a main highlight. Another one is Helibar?. This single-screw extruder provides immense advantages with regard to energy savings and durability. Tests have revealed: a 10 percent improved energy saving rate compared to state-of-the-art extruders of grooved bushing design can be achieved.

By retrofitting older machines with a new process unit (screw/cylinder) keeping the existing gear system/motor, the efficiency rises by 20 percent. Up to 60 percent savings could be achieved replacing the complete unit, i.e. a 90 screw diameter (OD) extruder with a 60 OD HELIBAR?. These exhibits are design components of a five-layer pipe extrusion plant which has been started up at a southern German pipe extrusion plant a few days before K 2013.

The five-layer pipe extrusion line, developed and produced by EXTRUDEX GmbH, Mühlacker/Germany, is characterised by high production speed and precision. The line has been delivered to customer by end of August and was started production within two days. Not it is used to produce pipes for floor heating systems. These consist of a core pipe layer, an adhesive tie layer, an EVOH barrier layer, a further adhesive tie layer, a protective layer in PE, as well as three stripes.

“It began with monolayer pipes earlier, later on 3-layer pipes were introduced into the market, consisting of a core pipe layer, an adhesive tie layer and the EVOH barrier layer. As the outer EVOH barrier layer dissolves easily in water and is very sensitive to mechanical damage, the EVOH barrier layer was moved to the interior of the pipe, and this is how the 5-layer pipe arose”, EXTRUDEX’s Managing Director Helmut Wahl explains.

The newer pipes even have internal protection for the EVOH barrier layer: this makes them even more secure and better sealed, so that no osmosis is possible. Wahl adds: “the five-layer pipe produced with our line meets the specific needs of the industry and is used as a high grade product for heating or cooling systems. It also finds use for wall heating”.

RT 2344, 2388 or DX800 grades of PE materials form the basis for the pipes. Six extruders in the line produce the final finished pipes in diameters from 16 to 25 mm.

“We have to respect layer thicknesses and tolerances on a micrometre scale”, Wahl stresses. The extruder applies and evenly distributes finest layers. The 16x1 and 17x1 mm [16 mm & 17 mm diameter, 1 mm wall thickness] pipes are produced with a speed of 30 m per minute in the required dimensions and tolerances. An ultrasonic measurement head measures the overall wall thickness inline, while an X/Y laser head controls the outer diameter. The fully automatic VR-3 vacuum calibration control unit ensures constant vacuum in the caliAir Jordan XIII High