Pulp and Paper Multiple Choice Questions on “Pulping”.
1. Pulp consists of 2 things which are, wood and the libocellulosic materials that are broken down physically and chemically.
a) True
b) False
Answer: a
Clarification: Pulp consists of wood and lignocellulosic materials that has been broken down physically and chemically.
2. Which are 4 broad categories of pupling processes?
a) Chemical, semi-chemical, chemi-mechanical, and mechanical
b) Qualitative , semi-chemical, chemi-mechanical, and mechanical
c) Quantitative, semi-chemical, chemi-mechanical, and thermal
d) Isentropic, semi-chemical, chemi-mechanical, and mechanical
Answer: a
Clarification: Following are the four broad categories of pulping:
Chemical, semi-chemical, chemi-mechanical, and mechanical.
These are in increasing order of mechanical energy required to separate fibers and decreasing reliance on chemical action.
3. Wood-free pulps contain no mechanical pulp or contains pulp subjected to a min. refining.
a) True
b) False
Answer: a
Clarification: Wood-free pulp contains no mechanical pulp or contains pulp subjected to a minimum of refining; consequently, at the time of its manufacturing the water drains from the pulp on the Fourdrinier wire.
4. ____________ is the process whereby the pulp is separated from large shives, knots, and etc.
a) Shredding
b) Cutting
c) Picking
d) Screening
Answer: d
Clarification: Screeing is the process whereby pulp’s separated from the large shives, knots, and etc. It contains accepts and rejects for further distinguishing.
5. ___________ are small finer bundles of fibers that have not been separated into individual fibers during the pulping process.
a) Shives
b) Yield
c) Grains
d) Pulp
Answer: a
Clarification: Shives are small finer bundles of fibers that have not been separated into individual fibers during the pulping process.
6. Which process is used to treat all types of woods for pulping process?
a) Mechanical pulping
b) Neutral-sulfite semi-chemical(N.S.S.C.)
c) Kraft process
d) Chemical mechanical pulping
Answer: c
Clarification: Chemicals used in this process are NAOH and Na2S. it is used to treat all types of wood. The yield strength of this would be 65-70%.
7. How to calculate the total yield?
a) Screening (%) + Screened yield (%)
b) Dry solid mass (%) + Screened yield (%)
c) Screening (%) + Slurry mass (%)
d) Dry product mass out (%) + Dry product mass in (%)
Answer: a
Clarification: The total yield is equal to amount of pulp removed while screening and the yield of pulp after the screens when all 3 are expressed as a percentage of the original wood put in the digester.
8. How to calculate consistency?
a) (Dry solid mass) (slurry mass)-1 x 100
b) (Dry solid mass)-1 (slurry mass) x 100
c) (Dry solid mass) (slurry mass)-2 x 100
d) (Dry solid mass)-2 (slurry mass) x 100
Answer: a
Clarification: Consistency is a measure of the solids content as a percentage in a pulp slurry.
9. How to calculate yield %?
a) (Dry product mass out) (Dry product mass in)-1 x 100
b) (Dry product mass out)-1 (Dry product mass out) x 100
c) (Dry product mass out) (Dry product mass out)-2 x 100
d) (Dry product mass out)-2 (Dry product mass out) x 100
Answer: a
Clarification: Yield % is a measure of the dry product mass content as a percentage in a pulp slurry.
10. Chemical pulping yields individual fibers that are not cut and give strong papers because of ________ as it interferes with hydrogen bonding is largely removed.
a) Pulp
b) Hydrogen
c) Phosphate
d) Lignin
Answer: d
Clarification: Chemical pulping yields individual fibers that are not cut and give strong papers since the lignin. Which interferes with hydrogen bonding is largely removed.
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