Pulp and Paper Multiple Choice Questions on “Refining”.
1. Pulp refining is a chemical treatment process of pulp fibers to evolve their papermaking properties in which paper properties depend on the product being made.
a) True
b) False
Answer: b
Clarification:Pulp refining’s a mechanical treatment process of pulp fibers to evolve their papermaking properties in which optmium paper properties, of course, depend on the product being made.
2. __________ is the production of rough surfaces on fibers by mechanical action; refiners break the outer layer of fibers and the secondary cell wall to protrude from the fiber surfaces.
a) Fibrillation
b) Drainage
c) Fiber cutting
d) Fiber brushing
Answer: a
Clarification: Fibrillation is the production of rough surfaces on fibers by mechanical action; refiners break the outer layer of fibers, and the fibrils from the secondary cell wall to protrude from the fiber surfaces.
3. A __________ is an early device used to treat pulp to improve the papermaking properties.
a) Refiner
b) Beater
c) Hinge
d) Spreader cone
Answer: b
Clarification:A beater is an early device used to treat pulp to improve the papermaking properties. Beating’s a batch process where the pulp slurry circulates through an oval tank around a mid-section and passes between a revolving roll with bars and a bed plate with bars.
4. What are the 2 types of refiners in refining?
a) Cubical and cuboidal
b) Circular and triangular
c) Disk and conical
d) Conical and circular
Answer: c
Clarification: There are 2 principal types: disk and conical refiners which are machines that mechanically macerate and/or cut pulp fibers prior to the process of making paper.
5. Refiners are machines that mechanically macerate and/or cut pulp fibers prior to making them into paper.
a) True
b) False
Answer: a
Clarification: Refiners are machines that mechanically macerate and/or cut pulp fibers prior to making them into paper.
6. What is the name of the part?
a) Cutting coarse bar
b) Double disk refiner
c) Twin flow refiners
d) Food processing
Answer: c
Clarification:Twin Flo refiner’s a double-disc refiner, which’s available for all types of fiber processing applications: e.g. recycled fiber pulp.
7. Fill in the blank.
__________= (Li X ∑ Wi)/ (∑ Wi)
a) Mass average length
b) Weight average length
c) Power average momentum
d) Work done average power
Answer: b
Clarification: L’s the length of the fraction of fibers with a length of i, N is the number of fibers of length i, and W is the weight of the fraction of fibers with length z. The weight average fiber length’s equal to or greater than the number average fiber length.
8. Fill in the blank.
__________= (∑ Ni X Li)/ (∑ Ni)
a) Pulp average processed
b) Mass average processed
c) Weight average processed
d) Number average length
Answer: d
Clarification: L is the length of the fraction of fibers with a length of i, N is the number of fibers of length i, and W is the weight of the fraction of fibers with length z.
9. __________ is a measure of the power input to the motors of the refiner based on the amount of pulp processed. It’s an indirect measure of the energy spent in cutting.
a) Refining power
b) Actualization power
c) Compartmentalization power
d) Degree power
Answer: a
Clarification: Refining power’s a measure of the power input to the motors of the refiner based on amount of pulp processed. It is an indirect measure of the energy expended in cutting and fibrillating .
10. In __________ both the burst and tear strengths are crucial, although increment in refining to raise the burst strength leads to less tear strength.
a) Brown paper bag
b) Polythene
c) Black paper bag
d) Carton bag
Answer: a
Clarification: In brown paper bags both the burst and tear strengths are crucial, although increment in refining to raise the burst strength leads to lower tear strength; hence, the tear strength of brown paper grocery sacks tends to be low.
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