Food Packaging Technology Questions and Answers for Entrance exams on “Manufacture of Tinplate – 3”.
1. The uncoated steel sheet before tinplating is known as ________
a) steelplate
b) bareplate
c) blackplate
d) foreplate
Answer: c
Clarification: The uncoated steel sheet before tinplating is referred to as blackplate, thus called because some of the early production was covered with black iron oxide. It is the raw material for electrolytic tinplate (ETP) and ECCS.
2. Cold rolling is carried out in a temper mill.
a) True
b) False
Answer: a
Clarification: The given statement is true. To reduce the possibility of severe fluting, paneling or creasing, and to impart the desired surface finish, the steel is given a final, very light cold rolling (generally a reduction of less than or equal to 5.0% in thickness) in a Temper mill.
3. ________ refers to an arbitrary number designation.
a) Etxruding
b) Polishing
c) Rolling
d) Temper
Answer: d
Clarification: Temper refers to an arbitrary number designation. This designation is the summation of several mechanical properties such as elasticity, springiness, stiffness and fluting tendency and therefore gives information about the forming properties of tin mill products..
4. Blackplate has _______ coating.
a) chromium oxide
b) aluminum oxide
c) iron oxide
d) zinc oxide
Answer: c
Clarification: Blackplate has iron oxide coating. At this stage, the uncoated steel sheet is referred to as blackplate, thus called because some of the early production was covered with black iron oxide. It is the raw material for electrolytic tinplate (ETP) and ECCS.
5. Temper in steel is measured by Rockwell hardness test.
a) True
b) False
Answer: a
Clarification: The given statement is true. The Rockwell hardness test has been adopted as the industry standard to express temper because of its simplicity and overall good correlation with fabrication requirements. This test is done with a 30kg load attached to a 1.6 mm diameter ball. The load is introduced into the plate surface. The measurement is taken and expressed as Rockwell 30T reading, which can be converted to temper values using arbitrary scale.
6. Type of steel in tinplate.
a) P
b) N
c) L
d) D
Answer: a
Clarification: There are four types of steel used in tinplate- D, L, N and MR. Steel D is used for drawing operations. Steel L is used for corrosion resistance. Steel N is nitrogenised steel. Steel MR is the most widely used tinplate steel used in the food industry.
7. Steel of type ____ is used where high internal corrosion resistance is required.
a) D
b) L
c) MR
d) N
Answer: b
Clarification: Steel of type L is used where high internal corrosion resistance is required. Its properties include- high purity; low in residual elements.
8. Steel of type ___ is used in can ends.
a) D
b) L
c) MR
d) N
Answer: d
Clarification: Steel of type N is used where high strength and rigidity required (e.g. can ends). Steel of type N is nitrogenized steel with up to 0.02% N to increase strength.
9. Steel type ___ is used for tinplates for packing vegetable and meat packs.
a) D
b) L
c) MR
d) N
Answer: c
Clarification: Steel type MR is used for tinplates for packing vegetable and meat packs. Vegetable and meat packs where internal corrosion resistance is not too critical. Steel type MR is similar to L but Cu and P maxima are raised. It is the most widely used tinplate steel.
10. Steel type ___ is used for tinplates in D&I cans.
a) D
b) L
c) MR
d) N
Answer: a
Clarification: Steel type D is used for severe drawing operations (e.g., D&I cans). This type of steel is stabilized steel and, therefore, non-aging. It contains less carbon than other tinplate steels.
11. Hot rolling imparts springiness to the steel.
a) True
b) False
Answer: b
Clarification: The given statement is false. Cold rolling imparts springiness to the steel. However, it changes the temper or surface hardness only slightly.
Food Packaging Technology for Entrance exams,