Extrusion Asia Edition 2-2020

D eveloped on the basis of the VENUS monolayer concept, Tecnomatic currently has a full range of die-heads with multi helical spirals, for the production of two, three or four lay- ers polyolefin pipes, even for large diameters, building on years of experience supplying reliable and high performing lines for multilayer pipes. A recent delivery of a line to Authentic Pro- duction in Myanmar for the production of multi-layer pipes up to 630mm shows that the Asia Pacific market is embracing in- novations that may provide higher levels of performance. Authentic Production, part of the Authentic Group of Compa- nies, which started its PE pipe production several years ago, has rapidly gained market share and reputation because of its focus on quality. They benefited from running Tecnomatic lines cap- able of producing pipes up to 1,200 mm that offered produc- tion efficiency, reliability and reduced scrap rates when produc- ing their recently launched multilayer product. The new prod- uct featured the BorSafeTM HE3494-LS-H PE100 High Stress Crack Resistant (HSCR) material in the outer layer to offer their clients maximum security against point loads and surface dam- age that may occur during installation. Such multilayer pipes have been used extensively in Europe for installations either using trenchless techniques or where no im- ported backfill is used. By using the same material dug from the trench, the installers were able to reduce the costs and environ- mental impact of bringing sand or other backfill materials to the site. HSCR PE100 pipes can now offer contractors and in- stallers such options in Asia as well. The wall of the multilayer pipe produced by Authentic Produc- tion is made up of two layers equal to 10 % and 90 % of the total thickness. The outer layer is produced from HSCR PE100 material and the core from standard PE100. This requires two separate extruders, which was achieved by a main extruder from the ZEPHYR series in L/D 40, which offers extreme output performance and lower melt temperature and energy con- sumption, while the inner layer is produced from an ATLAS series in L/D 30. Both extruders are synchronised using gravime- tric feed on each extruder to maintain a continuous raw mate- rial feed and to record variations in mass throughput, thereby ensuring perfect control of the weight per meter and wall thickness distribution. The VENUS MULTI pipe head series have been designed to achieve excellent processing using a wide range of materials at very high output. The spiral geometry has been optimised for the latest generation of PE and PP raw materials, while achiev- ing improvements in reducing its overall length, volume and operating pressure. The heart of the VENUS MULTI heads con- sist of an innovative flow channel geometry, which has been calculated to take into consideration the current raw materials. This geometry ensures the same behaviour for pressure and dis- tribution of the melt, in all the pipe heads in the range even at very high output rates. This new feeding system, as well as for the matching ranges and the small die sets contributes to the reduced working pressure. This reduces the energy consump- tion during extrusion since up to 10 % of the extruder power is usually required for pumping capacity. Lower pressure results in a lower melt temperature and together with lower residence times ensures improved pipe characteristics such as its OIT (oxi- dation resistance) and reduction of thermal and sheer stresses. Authentic Production has expressed a high degree of satisfac- tion for the quality of the multilayer line since its commission- ing. The new product will offer project owners additional secu- rity for pipelines that are installed in demanding conditions. Ad- ditional features can be added to the pipe such as a peelable outer skin, which provides further economic and environmental benefits for water and gas distribution pipelines. This peelable outer jacket, frequently made from specially modified polypro- pylene, further protects the pipe surface against potential notches and cracks when using installation methods such as pipe bursting or wash-boring. Potentially deep scores in the protective jacket will not be transferred to the inner pipe when it is eventually exposed to service-related stresses. The peelable jacket that is adhered to the outer wall of the core PE pipe is typically 0.6 to 0.7 mm thick for all current dimen- sions of this new multi-layered pipe and the skin is added by a cross-head positioned before the last cooling bath. Tecnomatic has a full range of die-heads, based on spiral or radial techno- logy suitable for plastic or metal pipes coating ranging from 5 to 800 mm and up to 4 layers. The die-heads are based on a ty- pical spiral technology for large and single layer co-extrusion or a mixed solution with radial distributors or short path spiral al- ternative depending on material characteristics such as PA, EVOH, PVDF or adhesive bonds. VENUS 630 模头的螺旋分配器 VENUS 630 die-head spiral distributor ➠ Tecnomatic SRL Via Emilia, 4 – 24052, Azzano S.Paolo (Bg) Italia https://tecnomaticsrl.net 26 管材挤出 Extrusion Asia Edition 2/2020