TPT September 2011

T echnology U pdate

INCREASINGLY, large diameter pipelines are being requested in plastic. Accordingly, Sica has introduced new haul-offs and planetary saws for processing polyethylene pipes of diameter up to 2,000mm. The structural configuration of these machines is designed to meet the particular operating requirements for those types of lines: the range of pipe sizes to be produced; start-of- extrusion systems; line production capacity; machine installation logistics; energy source availability; quality control of produced item; and safety procedures. The P 2000/14 Plus haul-off has fourteen caterpillars; the upper eleven pivot (Sica patented system), while the lower three are positionable electromechanically. All the caterpillars are anchored via connecting rods to the machine frame, so that reaction forces are transferred to both sides of the frame, with clear advantages in terms of structural efficiency and therefore better mechanical performance. The caterpillars have contact length of up to 2,200mm and width up to 116mm. With DN1200 to The maximum external pipe diameter that can be cut is 2,000mm; the minimum external diameter is 450mm. To best adapt to the pipe surface, the machine is equipped with universal clamps, with each clamp arm having multiple rubber and pivoting gripping elements. The frame of the planetary saw is made of cold rolled steel sections affording superior stiffness and resistance to stresses. To facilitate safe maintenance procedures, in semi- automatic mode the movement phases are performed using two-hands type controls. The machine control system, using PLC logic, includes a graphical touch-screen for quickly and intuitively controlling the entire haul-off and cutting process. For diameter changes, machine configuration is altered directly from the control panel without manual intervention, by simply selecting the recipe corresponding to the process parameters for the new pipe. Sica – Italy Website: www.sica-italy.com Cutting system for 2,000mm HDPE pipes DN2000 pipes, a maximum pulling force of approximately 400,000N is generated using fourteen caterpillars. Whereas, with DN630 to DN1000 pipes, the pulling force is approximately 170,000N using six caterpillars. The working speed range is from 0.002m/min to 0.9m/min. The caterpillars are interlocked in a double master-speed control loop. That is, the machine is equipped with two transducers that monitor continuously the pulling of the pipe, guaranteeing complete operational safety even if one of the transducers malfunctions. Power is transmitted to the caterpillar chains by parallel shaft speed reducers, so there are no axial reaction forces penalising mechanical efficiency, which typically occurs with right angle, shaft speed reducers. The TRK/C/Sy 2000 is a planetary saw with a tool that cuts without removing material; so it is swarfless and generates no dust. The saw is suitable for polyethylene pipes with wall thickness up to 130mm.

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S eptember 2011

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