A unique pipe extrusion line, 3 layers up to 1,200 mm, for the long-standing customer LUNAPLAST.

Tecnomatic, a recognized market and technology leader for the production of pipe extrusion lines, has won a contract with a leading supplier of PE pipes. LUNAPLAST a.s. – Czech Republic has placed an order at the beginning of 2022 for a high technology pipe extrusion line, to produce multilayer polyolefin pipes with diameter up to 1,200 mm, in 3 layers for pressure application, with additional PP protective layer and jacketing pipes, according to EN 253 norm for distric heating, at their plant in Melnik.

LUNA PLAST a.s., established in 1994, began its activity in the Czech market as a manufacturer of protective PE pipes for cables and optical cables. Today, the company takes pride in offering a far broader product portfolio, with the production being primarily focused on PE pressure pipes for water, sewerage, gas and irrigation applications, geothermal probes, threaded PE pipes for non-pressure applications and PE fittings for pipe joining. The Company currently owns and operates state-of-the-art-equipment, and with the new order is extending its product portfolio to pipes up to 1,200 mm in diameter and in a three layers configuration, which represents a unique production in the EU countries.

To this end, the line is equipped with the most modern technology available for pipe extrusion, starting with a pre-heating treatment for all the materials, which are weighed by an automatic gravimetric dosing system, fully integrated in the line control, and able to manage a total of eight components: four for the main extruder and two for each one of the side extruders.

A 1,200 mm singlescrew extruder for the main layer from the 37D VEGA series and two 60 mm co-extruders from the ATLAS 30D series are capable of plasticizing up to 2,200 kg of resin per hour with optimal melt homogeneity. The proven Vega and Atlas machines come with anti-wear coated screw and barrel, equipped with synchronous AC motors, while solid gearboxes characterised by a cast iron single-piece frame, independent oil cooling unit and high-performance bearing group (up to 500 bar) assures the maximum realibility in the power transmission.

The extruder and the line are controlled by the new EPC III (Extrusion Process Control), a new Multitouch Capacitive Panel PC Platform, with integrated Web Server and 4.0 connectivity, UL certified. The new 21.5-inch TFT LED display, with a wide viewing angle and Linux operating system combined with 64-bit RISC quad core – 1.6GHz processors, guarantees high performance of the integrated graphics libraries and allows to have numerous plug-ins and widgets available, such as HTML browsers, PDF and video viewers, as well as the ability to create and print reports. Developed on the specific needs of operators, it allows the integration and control of all components such as: gravimetric, co-extruders and corrugators, gear pumps, screen-changers, calibration tanks, haul-off and cutters. The integration and management can take place through the most common analog communication protocols or the more modern OPC-UA, in accordance with EUROMAP 84.

The heart of the line in any multilayer pipe production line is the die head. To this regard, Tecnomatic has further optimized its VENUS MULTI 3-1200 die head, which is based on a three spirals design to ensure the optimal melt flow for a wide range of thickness ratios. The die-head is compact with a low pressure build-up and consequent energy savings. It covers the full size range from 315 to 1,200mm, producing three diameters per die-set for sizes up to 800mm, using the classic draw-down mode and, for larger sizes, the swelling mode for a better control of wall thickness distribution and pipe ovality, assuring production up to SDR 11 (109 mm) in 1,200 mm size. The die-sets comprise of two parts with a small end ring to define the gap of the die, permitting a rapid size change and adjustment. A Pipe Air Cooling (PAC) system provides intensive cooling of the inner pipe surface by sucking air in the opposite direction to extrusion. By forcing the air flow it ensures uniform cooling around the pipe and through the wall thickness, decreasing the differences in the pipe solidification rate and reducing the residual internal stresses.

The performance of such an extrusion line gains definite advantages from the suitable design and correct use of tanks, calibrators and down-stream machines as haul-off and cutter. In order to manage an output over 2,000 kg/h and thickness up to 109 mm, the line is provided with a cooling length of almost 50 m, where 22 are made by vacuum tanks. The haul-off, able to pull at outstanding Nm force, is equipped with independently driven caterpillars controlled by vector motors, long caterpillars to assure a good grip with bow profile and an antisqueezing system for the production of jacketing pipes for district heating. A planetary saw with circular blade assures a perfect pipe cut even with high wall-thickness without extraction of material. The cutter is provided of hydraulically driven cutting arm, a balanced cutting motor, universal clamps with rubber pads for efficient grip and of a synchronization for the adjustment of carriage speed as extrusion speed varies, to assure higher precision in cutting length.

Two additional important devices are completing the configuration of this high technology line. To have a perfect measurement over the entire circumference of the pipe a Terahertz system is used. This allows the measurement of layer thicknesses from 100 µm with a measuring rate of 100 Hz. Further for the production of jacketing pipes a surface treatment to increase surface wettability through electrical discharge is applied. The corona system is designed for treatment or cleaning the inside surface of jacket pipes for an optimised adhesion of PUR foam, which is needed for insulation of the pipe core.

Both companies are particularly enthusiastic about a project that represents a milestone and a unique line for the plastic pipe production in the European market.