1. Chemical reagents used in digestors of Kraft process are ____________
a) Mg(HSO3)2 + SO2
b) Na2 CO3, Na2SO3, NaHCO3
c) NaHSO3, Na2SO3
d) NaOH, Na2S, Na2CO3 In aqueous solution
Explanation: 60%NaOH, 25% Na2 S, 15% Na2CO3 in 10-15%aqueous solution is the chemical reagent used in digestors of sulfate pulp process Mg(HSO3)2 + SO2, Na2CO3 + Na2S + NaHCO3, NaHSO3 + Na2 SO3 are the chemical reagents used in different types of sulfite processes.
2. Stabilizer added to maintain the peroxide (bleaching agent) concentration is ___________
a) Chlorine
b) Nitrate
c) Sodium silicate
d) Phosphoric acid
Explanation: Chlorine is not a stabilizer and generally sodium silicate is used as stabilizer for maintaining the peroxide concentration. These days it is replaced by an organic dye to prevent scale formation on internal surfaces.
3. Which of the following takes less time for digestion in Kraft process?
a) Bagasse
b) Paper pulp
c) Wood base material
d) Lignin free chemical cellulose pulp
Explanation:It might take 5-6 minutes for Bagasse, 2-5 hours for wood base material, longer time for lignin free chemical cellulose pulp, and a short time for paper pulp.
4. Which material is used for construction in Kraft process?
a) Mild steel
b) Bronze
c) Lead
d) Acid proof brick
Explanation: Bronze, lead, and acid proof brick are materials of construction in sulfite process whereas mild steel is used in Kraft process as well as neutral sulfite process.
5. Brown color pulp is produced in sulfite pulping process.
a) True
b) False
Explanation: The statement is false as brown color pulp is produced in sulfate pulping process whereas sulfite process produces dull white color pulp which can be easily bleached.
6. Composition of ideal fiber required for paper making is _______________
a) High cellulose content, high lignin content
b) High cellulose content, low lignin content
c) Low cellulose content, high lignin content
d) Low cellulose content, low lignin content
Explanation: Ideal fiber having high cellulose content and low lignin content is very much suitable for making best quality paper. Paper is matted sheets of fibers formed by preparing fiber suspension followed by its conversion to paper.
7. Which type of paper is used in producing cigarette paper product?
a) Wrapping paper
b) Book paper
c) Tissue paper
d) Writing paper
Explanation: Cigarette, carbon, napkin, towel, toilet papers are produced from tissue paper. Book paper produces lithograph offset, textbook paper. Wrapping papers produce linen papers etc.
8. Fillers are added to reduce water penetration into paper products.
a) True
b) False
Explanation: Sizing is added to reduce water penetration whereas fillers are added to increase brightness, flexibility, opacity, bulk, weight of finished product, and softness.
9. What is the capacity of single fourdrinier paper machine per day?
a) 50-100 tons
b) 400-500 tons
c) 1000-2000 tons
d) around 5000 tons
Explanation: The capacity of single fourdrinier paper machine per day is 400-500 tons of paper. Fine tissue and laminated paperboard stock can be produced by modifying the machine.
10. The consecutive steps involved in formation of paper are __________
a) Web forming, pressing, drying
b) Web forming, drying, pressing
c) Pressing, web forming, drying
d) Drying, web forming, pressing
Explanation: Web is formed by running the water-fiber slurry onto moving endless wire belt cloth where water gets drained; remaining water is removed by passing through pressure and suction rolls followed by pressing, drying and finishing gives the paper (final product).