Pipehead The QuickSwitch pipehead has a movable pin centred in the die. The pin and the die are both conical, tapering towards the melt exit gap. Changing the axial position of the pin changes the size of the melt exit gap. The pin positions for different diameters and wall thicknesses can be programmed into the control system. To make sure that subsequent pipe shrinkage is within the set tolerances, the gap size must be set to correspond exactly with the projected pipe wall thickness, taking account of die swell during the extrusion process. We supply QuickSwitch pipeheads for production of PVC pipe and for single- or multilayer PO pipe.

Suction bell
The suction bell, between the pipehead and the calibration basket is sealed at both interfaces. When necessary, the suction bell expands the flexible melt tube to the required calibration diameter.

Calibration basket The key component of every QuickSwitch extrusion line is the adjustable calibrating basket. The calibration basket gives the pipe its final shape. In contrast to a conventional calibration, the QuickSwitch calibration basket changes diameter steplessly across the whole range specified for that line. The calibrating basket is made up of multiple segments that move to produce the set diameter, always forming an absolutely round cylindrical tube with a smooth surface.

End seal
The vacuum tank must be sealed on the intake and exit side so that underpressure can be built up. In the intake zone, the seal is created by the calibrating basket together with the plastic tube itself. The vacuum tank exit has a special QuickSwitch end seal made up of several movable segments. This segmented construction, in combination with spring forces and water pressure, ensures that the vacuum tank is completely sealed off against ambient pressure over the whole diameter range of the QuickSwitch system. When the diameter changes, the end seal adjusts automatically to the new diameter. A conventional pipe extrusion system is fitted with a seal usually selected for one specific pipe diameter only.

Roll guides
To avoid ovality caused by uneven cooling, the extruded pipe must be exactly centred as it travels through the spray baths and, even more important, through the vacuum tank. A QuickSwitch system uses combo rolls that guarantee the pipe is always supported, centred and correctly shaped. The support function is ensured by alternating rolls with two different special geometries.

Haul-off
The caterpillar haul-off pulls the melt tube at an even pace through the extrusion line. Pneumatic cylinders maintain the pressure of the upper track against the pipe, the pressure of the lower track is maintained by means of electric motors. Sensors measure the actual pipe diameter and the feedback is used to correct the position of the caterpillar tracks. This means the required haul-off force is constantly applied. When the diameter changes, the haul-off adjusts automatically to the new diameter. Contact pressure is also adjusted automatically. These systems ensure that, even during the actual dimension change, the pipe is always centred and pulled smoothly with the right force and speed.

Cutter
The cutter also adjusts to diameter changes, activated by its own diameter sensing system. The cutter’s clamp system adjusts to the actual pipe diameter. This means no resetting effort is required for the cutter when the dimension changes.

Control
The control system controls the entire automated QuickSwitch line using the preset parameters that are entered and stored for each pipe dimension. The required data record is simply selected and activated at the touch of a button. Within minutes, the whole QuickSwitch line adjusts automatically to the selected pipe dimensions. After producing a couple of meters of waste pipe during the changeover, the system quickly stabilizes to produce pipe of outstanding quality.

Other line components, eg, embossing and marking devices, can be supplied as QuickSwitch versions on request.

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