TPT July 2007

P lastic & C omposite T ube: P roducts & M anufacture

Latest single-screw extruder for PP/PE 100 pipe production

Cincinnati Extrusion GmbH, Austria, have launched the Monos high-performance extruder series. This extruder generation is designed to meet current market demands for high throughput rates and optimal melt homogeneity, regardless of the materials, granulates and fillers being processed. Using these modern single-screw pipe extruders, gas and water transport pipes are produced from PE 100 and PE 80 material, smooth and corrugated pipes

from PP-H, PP-B and PP-R, and corrugated wastewater pipes from and all types of PE 80.

Another top priority for this technology is maximum melt throughput in relation to screw diameter. Additional required attributes are optimal melt temperature and homogeneity.

› Figure 5: Consistency in specific melt throughput during ‘stiff’ PP processing

fi Figure 1: The Monos high performance single screw extruder

With virtually any die concept and also using mixed in filler materials – even at back pressures of up to 400 bar – the specific melt throughput rate remains stable over the entire screw speed range of this machine.

Cincinnati has developed a modular screw concept for the new 37 D version to allow for the processing of all available types of PE and PP as well as compounds, reclaims, regrinds and colour masterbatches. The modular

thinner pipe with the same mechanical properties. ‘Stiff’ PP is such a material, which also gives pipes a high-quality appearance. Due to its attributes, it can be assumed that ‘stiff’ PP will be in great demand in the future. However, processing ‘stiff’ PP – with its high crystallinity at high melt throughput rates – presents a new challenge to extrusion equipment manufacturers. Due to its substantially higher E-module, the screws must be specially designed with a completely different geometry. The torque of the drive and the driving motors must have sufficient power reserves, especially for the start-up process. Another frequently applied method to reduce material costs is adding fillers, such as chalk, talcum, barium sulfate or fibreglass. Currently, compounds with up to 50 parts of filler content are being used, where processors must take care that the required quality standards for the finished pipe can still be met. Cincinnati Extrusion GmbH – Austria Fax : +43 1 610 068 Email : welcome@cet-austria.com Website : www.cet-austria.com › Figure 4: High crystallinity matrix of ‘stiff’ PP, Borealis BA 212E

screw concept also ensures manageable provision of spare parts. The most common approach in reducing unit costs is in the area of material expenses. By using a type of polymer with a higher E-module, it is possible to produce

fi Figure 2 (bottom): Linear ratio between melt throughput and screw speed for various types of PE granulate (with and without chalk content) Figure 3 (below): Modular screw concept for the Monos 37D series

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J uly /A ugust 2007