This large co-ex film blowing line was recently installed in the new 5,000 sq. meter factory building in Labtech Engineeering. Here we have set up a large air conditioned room with high ceiling to be our application laboratory with the purpose to perform complete tests for our customer. In the same room we are also building a brand new high speed 7 layers co-ex chill roll line which will use the extruders from this 9-layers film blowing line.
The 9-layers co ex film blowing line is built up with the following machines: 2 units 30 mm extruders and 7 units 25 mm extruders, all with 30 L/D.
The extruders are all adjustable in height so they can be connected to any level of the high pancake die. They are also mounted on sturdy platform with casters so they can be rolled away and be used for other downstream applications.
All extruders are equipped with gravimetric hopper feeders which will allow for a very precise control of each layer thickness.
The feeders are all controlled from a central touch screen where the feed rate for each extruder can be keyed in in gram per minute or in percent of the total 9 layers.
All 9 extruders are connected to the die with short straight line die adaptors and the each extruder is equipped with a screen changer as well as pressure and melt temperature transducers which will measure pressure and temperature both before the screen and at the die layer inlet.
The extruders can be placed close to the die thanks to their narrow design and this also allow for minimum feed pipe lengths from extruder to die which in turn is very beneficial for certain resin types that are sensitive to gel formation as well as degradations.
The die as well as connecting adaptors shown here are surrounded by heat protecting steel grids.
The die comprises of 9 individual layers which are partially insulated against each other with a small air gap. Each die layer comprises of two halves where the flow channels have been machined equally on both upper and lower half, enabling that the channels have a perfect round cross section which is very important for a good resin flow without dead corners.
The die has been designed by our Canadian consultant, John Peridikoulias of Compuplast. Each layer was design to be as universal as possible but still some layers had to be made for specific resin types such as EVOH, Nylon, Tie layer etc.
The die is equipped with a high efficiency dual channel air ring with variable speed blower. Also the air is cooled with a large chiller. The air pressure and temperature is shown with large dial gauges on the air ring.
The film tower is equipped with an oscillating Nip-Roll which slowly rotates 360 degree back and forth allowing for very even film rolls. The film bubble is collapsed in an A-frame with carbon fiber rollers inside the oscillating nip-roll. The film bubble is also stabilized with to sets of bubble cages, each with 6 rows of Teflon rollers.
Downstream the tower is equipped with a film width sensor which will automatic inflate or deflate the film bubble to a preset film width. The width is set on a touch screen controller mounted on the control panel.
Also downstream there is a two sided Corona treater shown above which will treat the upper and lower part of the film.
The film is split at the edges and then lead through a pair of Nip-Rolls and further to the 2-station wind up/.
The whole line is controlled on a central large touch screen panel where all parameters for all extruders, die layers tower, wind up etc are set and read out on graphic illustrations. All data can be down and uploaded as well as manipulated with a tailor made software.
This line is made by Amse, italian company based in Torino.
