Pulp and Paper Interview Questions and Answers on “Related Pulping Methods”.
1. The Asplund process was developed about 30 years prior to TMP.
a) True
b) False
Answer: a
Clarification: The Asplund process was developed about 30 years prior to TMP.
2. Asplund process involves pre-steaming wood chips at temperature above the glass transition temperature of lignin.
a) True
b) False
Answer: a
Clarification: The Asplund process was developed about 30 years prior to TMP. It involves pre-steaming wood chips at temperature above the glass transition temperature of lignin. 550-950 kPa steam pressureat 150-170 degree Celcius.
3. What is the pressure range at which the wood chips are pre-streamed?
a) 1300-1950 kPa
b) 550-950 kPa
c) 42-78 kPa
d) 1285-1950 kPa
Answer: b
Clarification: The Asplund process was developed about 30 years prior to TMP. It involves pre-steaming wood chips at temperature above the glass transition temperature of lignin. 550-950 kPa steam pressureat 150-170 degree Celcius.
4. What is the steam pressure range at which the wood chips are pre-heated?
a) 50-200 degree celcius
b) 300-340 degree celcius
c) 1500-2000 degree celcius
d) 150-170 degree celcius
Answer: d
Clarification: The Asplund process was developed about 30 years prior to TMP. It involves pre-steaming wood chips at temperature above the glass transition temperature of lignin. 550-950 kPa steam pressure at 150-170 degree Celcius.
5. The lignin is sufficiently soft that the separation occurs at __ lamella, and fibers are left with just a hard lignin surface.
a) Upper
b) Lower
c) Middle
d) Outskirt
Answer: c
Clarification: The lignin is sufficiently soft that separation occurs at the middle lamella, and fibers are left with a hard lignin surface.
6. What is the other name of Masonite process?
a) Ignition process
b) Steam explosion
c) Mason process
d) TMP
Answer: b
Explosion: The other name of this process is called ‘steam explosion’. Chips are steamed at 180-250 degree celcius.
7. What is the temperature range at which chips are steamed in the Masonite process?
a) 1500-1690 degree Fahrenheit
b) 35-80 degree Fahrenheit
c) 155-480 degree Fahrenheit
d) 335-480 degree Fahrenheit
Answer: d
Clarification: The other name of this process is called ‘steam explosion’. Chips are steamed at 180-250 degree celcius.
8. What is the range of yield in the Masonite process?
a) 50-60%
b) 40-30%
c) 80-90%
d) 10-20%
Answer: c
Clarification: In fiberboard the fibers are held together by resins such as phenol-formaldehyde. The yield is 80-90%.
9. Chips are steamed well above the glass transition temperature of lignin, for one to two minutes until final pressure is on the order of __ MPascal.
a) 14-20
b) 4-7
c) 19-25
d) 3-4
Answer: b
Clarification: Chips are steamed well above the glass transition temperature of lignin, for one to two minutes until final pressure is on the order of 4-7 MPascal.
10. A mild explosion pulping process is being used at one mill to process __ paper.
a) Recycled
b) Un-used
c) Over-used
d) Bloated
Answer: a
Clarification: A mild explosion pulping process is being used at one mill to process recycled paper.
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