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 Denmark - Færch Plast
is betting on the newest ZSK technology.
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Maximum efficiency, higher torques, improved performance, and optimum product quality convince the Danish plastic film producer Færch Plast to use the latest ZSK MEGAcompounder on its entire line
For over a year, the Danish company Færch Plast GmbH in Holstebro has been producing its crystal-clear PET thermoforming sheet on a direct extrusion line for which Battenfeld extrusion technology is entirely responsible. The convincing results, which can be measured by an efficiency of 98% and the speck-free, high-quality film, among other things, have been so successful that a second line has been installed, and after only three days is already producing flawless films for further processing.
Like the first line, the new PET thermoforming sheet line has thoroughly convinced the customer. Two Coperion Werner & Pfleiderer co-rotating twin-screw compounders, which are optimally designed for the gentle plasticization of undried polyester, also contribute to this: a ZSK 119 MEGAcompounder PLUS as the main extruder and a ZSK 70 MEGAcompounder as the co-extruder – two highly productive co-rotators of the newest generation, which surpass their predecessors by yet higher torques and a further optimized performance. Thus the maximum plasticizing capacity of the two extruders together is 2,400 kg/hr with optimum product quality.
| Greater efficiency, less energy consumption |  | |
The efficiency of the new plant not only increases productivity but also reduces costs. Up to now, to process PET in conventional plants it was necessary to pre-dry and crystallize the pellets at 160°C for up to 6 hours in order to prevent hydrolytic polymer chain degradation during the processing as far as possible. Now the ability to process PET without previous drying, represents an enormous potential for saving energy. During direct extrusion, the drying takes place directly in the extruder. With an optimally designed 3-stage vacuum degassing plant, both the surface moisture and the water formed by hydrolysis can be drawn off from the process chamber and thus the polymer chain structure can be optimized. Other undesired by-products are also removed reliably from the melt at up to 2 mbar, without impairing the vacuum plant in any way.
| Large amounts of recycled material, no problem | | |
The new Færch PET line is fed directly from the virgin pellet and recycled material silos, so that up to 70% recycled materials can be incorporated without sacrificing quality. Thanks to a high-precision gravimetric weigh feeder, any desired formulation can be selected and thus it is possible to respond quickly and effectively to changing requirements. In addition, special control software developed and optimized on the first line during continuous operation ensures trouble-free operation of the plant, even with high percentages of recycled material.
| Specific requirements, specific solutions | | |
Maximum flexibility at minimum film tolerances is a tall order, but the new line is more than up to the challenge. For example, the plant, which is designed for a net film width of 1,920 mm at a film thickness of 200 to 1,300 µm, has a die with internal deckling that ensures the necessary flexibility. Narrower film widths can also be achieved without major adjustments and production interruptions. Minimum film tolerances are ensured by the chill-roll plant with hydraulic nip adjustment mechanism, which is inclined by 30° for easy access and in which special-purpose rolls 2,400 mm wide are used. The deflection occurring particularly at high line loads is absorbed by an inner roll bearing, so that the roll jacket is always parallel to the nip. At the end of this optimized chill-roll process, speck-free, crystal-clear PET films are then cut at a cutting station, wound up on large 1600 mm rolls, and are thus optimally prepared for the subsequent thermoforming process.
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