K
Kaolin
White clay used as an additive and filler in paper and coating made up chiefly of minerals of the kaolinite type.
Kappa Number
A term used to define the degree of delignification. Modified permanganate test value of pulp which has been corrected to 50 percent consumption of the chemical. Kappa number has the advantage of a linear relationship with lignin content over a wide range. Kappa Number x 0.15% = % lignin in pulp
Kenaf
An annual agricultural plant, native of India, which has along fiber in the bark that, is suitable for papermaking.
King Roll
The bottom roll in a calender stack, usually the largest diameter in the stack and the only driven roll in the stack.
Kiss Impression
The lightest impression (anilox and plate to substrate) possible to properly reproduce the image on paper.
Knotter
Vibratory screens used for separating knots, uncooked chips and shives from the pulp at the blow tank.
Knotter Pulp
Pulp made from the rejects from chemical pulp screening.
Kozo
The most common fiber used in Japanese papermaking, it comes from the mulberry tree. It is a long, tough fiber that produces strong absorbent sheets.
Kraft Bag Paper
A paper made of sulfate pulp and used in the manufacture of paper bags. It normally has a greater bulk and a rougher surface than the usual kraft wrapping paper.
Kraft Paper
A paper of high strength made from sulfate pulp. Kraft papers vary from unbleached Kraft used for wrapping purposes to fully bleached Kraft used for strong Bond and Ledger papers.
Kraft Pulp
Chemical wood pulp produced by digesting wood by the sulfate process (q.v.). Originally a strong, unbleached coniferous pulp for packaging papers, kraft pulp has now spread into the realms of bleached pulps from both coniferous and deciduous woods for printing papers.
Definition of Kraft Pulping Terms
S.N.
Term
Definition
Unit
1
Total Alkali (TA)
Total of all viable sodium alkali compounds i.e. NaOH+Na2S+Na2CO3+Na2SO4+Na2S2O3+Na2SO3 excludes NaCl
g/L as NaO
2
Total Titratable Alkali (TTA)
Total of NaOH+Na2S+Na2CO3
g/L as NaO
3
Active Alkali
Total of NaOH+Na2S
g/L as NaO
4
Effective Alkali
Total of NaOH+0.5*Na2S
g/L as NaO
5
Activity
Ratio of Active Alkali (AA) to Total Titratable Alkali (TTA)
%
6
Causticity
Ratio of NaOH to NaOH+Na2CO3
% on NaO basis
7
Sulfidity
Ratio of Na2S to Active Alkali (AA) or to TTA (Basis of sulfidity should be defined accordingly)
% on NaO basis
8
Causticizing Efficiency (White Liquor)
Same as causticity i.e. Ratio of NaOH to NaOH+Na2CO3 however to measure the true causticizing efficiency NaOH amount in green liquor already present should be subtracted.
% on NaO basis
9
Residual Alkali (Black Liquor)
Alkali concentration determined by acid titration.
g/L as NaO
10
Reduction Efficiency (Green Liquor)
Ratio of Na2S to all Na sulfur compounds (Na2S + Na2SO4+Na2S2O3+Na2SO3).
% on NaO basis
Kraftliner
Paperboard of grammages of 120g and more, generally made from bleached or unbleached sulfate pulp and used as an outer ply in corrugated board.
