W&H 5 layer cast extrusion line
|Machine||W&H 5 layer cast extrusion line|
|Type of extruder||Cast|
|Number of layers||5|
|Diameter screw(s)||120, 70x2, 45x2|
|Material & Min – Max thickness||CPP, PA, EVOH, Carasine, PE|
|Max. film width||1920 mm|
|Min. – Max. film thickness||20 – 250 mu|
|Max. output||350 kg/hour|
|Max. rewind reel diameter||1000 mm|
|Number & sizes airshafts for winder||152 x 2|
|Edge guide(s)||Yes, BST|
|Corona treater||Yes, 2x|
|Spare parts||Extra die|
|Machine can be seen in production?||Yes|
W&H, Windmöller & Hölscher
The W&H Group produces extruders, printing presses en converting machines. For more than 140 years W&H has been manufacturing converters for flexible packaging. They have sold over 5000 machines in more than 140 countries. This German based company has its plant in Lengerich.
Extrusion in the flexible packaging industry can roughly be devided in three kinds of extrusion: blown film extrusion lines, cast film extrusion lines and BOPP extrusion lines. Cast Film Lines
In the process of cast extrusion polymer travels through a flat die system. For mono-layer extrusion only the die is required. For co-extrusion besides the die you need also aa feedblock.
The extruders melt and mix the material, they filter it and i t will be be fed to the die system. The molten curtain enters the cooling unit directly after leaving the die. A roll cooled by water will freeze the film.
The edges will be trimmed and when required corono treatment is applied. The last stage of the process is winding the film onto rolls.