Non-woven and machinery Flashcards
Which three processes to produce Non-woven materials do you know? Briefly explain the technology and difference between the processes!
- Airlaid
o Doesn’t use water, you lay the fibres on a suction belt with air. Strength of material comes from the fact the fibres are so long - Spunbond/melt blown
o Melted polymer is extruded to create a web which can then by wound on a winder. - Wet-laid
o Uses water, similar to paper making as fibres are brought to a wire, however this is an inclined wire and the consistency compared to a normal headbox is much lower (~0.05-0.1%) low consistency is due to the long fibre length, need it in order to get good formation. The incline helps to support dewatering,
Please describe the principle of an inclined wire paper machine! What are the main differences compared to a standard (long-wire) paper machine and what products can be produced on these machines?
Much like a standard paper machine. But fibres are sprayed from the headbox with a much lower consistency (~0.05-0.1%), the incline of the wire helps dewatering. There is good control over porosity and pore size distribution. These machines can make non-wovens, filter papers and abrasive base papers. I comparison to regular paper machines the speeds are much slower. There is high amount of synthetic fibres and water.
What are the advantages of a Non-woven wallpaper compared to a classical paper wallpaper?
Very user friendly. Environmentally friendly because vinyl free. Breathable so helps with mould. Do not shrink when dry. No wrinkles! Removal is a lot easier.
Please name different product designs for non-woven wallpaper! What printing technologies can be used to print on non-woven wallpaper?
Uncoated non woven – low end applications usually a base for further coating
Single coated non-wovens, improved quality.
Double coated non woven – highest smoothness and used for direct printing (rotogravure).
PVC coating or rotogravure direct printing
