Question

The kappa number of bleachable hardwood pulps is ________

(a) 20–30

(b) 30–40

(c) 10–20

(d) 18–20

The question was asked by my college professor while I was bunking the class.

The origin of the question is Chemical Pulping & Semichemical Pulp in section Paper and Paper Based Packaging Materials of Food Packaging Technology

Answer 1

Right choice is (d) 18–20

The best I can explain: The kappa number of bleachable hardwood pulps is 18–20. This indicates that hardwood pulp has lower lignin content than softwood pulp. Lignin does not have fiber forming properties, hence, hardwood pulp does not make as strong paper as softwood pulp.