Fibres for specialty papers

Question 1

 Please name at least 5 natural fibres which can be used for specialty paper production!

Answer 1

• Leaf fibres (abaca)
• Grass fibres (bamboo, bagasse)
• Stalk fibres (wheat/straw)
• Seed fibres (cotton)
• Bast fibres (Hemp)

Question 2

What are the main differences of specialty fibres compared to normal wood pulp?

Answer 2

There can be a big difference in component composition – eg cotton is almost pure cellulose whereas bagasse is quite inhomogeneous and has around 30% pith fibres. and length

Question 3

 What are the main differences between Bagasse and Bamboo fibres? How do they compare to normal wood pulp?

Answer 3

Bamboo has long fibres and is extremely fast growing, the long fibres give it good tensile strength. Bagasse can be problematic for papermaking as it is an inhomogeneous material. When comparing these sources with wood pulp we see differences in refining behaviour. The bamboo is comparable whereas the bagasse produces a lot of fines during refining. This changes the smoothness and porosity characteristics, the bagasse will create a smooth and dense sheet in comparison.

Question 4

What is dissolving (regenerated) pulp? Please give some examples of dissolving pulp fibres and name a few applications of these fibres!

Answer 4

Dissolving pulp is purified cellulose pulp (low hemicellulose content) which is suitable for further chemical conversion into a range of products. The dissolved pulp can be spun into textile fibres cast into films or regenerated into a sponge. Common application is creation of viscose fibres for use in clothing, dissolving pulp can even be used in the cosmetic industry

Question 5

What paper properties can be improved with specialty fibres (natural, synthetic or regenerated fibres) compared to standard wood pulp fibres?

Answer 5

With regenerated fibres you can modify the fibre shape to increase absorbency, eg increasing surface area or creating hollow segments, this design cannot be influenced in standard wood fibres.
With many specialty papers we can influence the strength, mainly to the fibre length, cotton has an extremely large length so can therefore increase tensile and massively increase fold endurance. Additionally bamboo has large length with high tensile and good water resistance.