Food Packaging Technology Questions and Answers – Manufacture of Tinplate – 1

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This set of Food Packaging Technology Multiple Choice Questions & Answers (MCQs) focuses on “Manufacture of Tinplate – 1”.

1. The thickness of a tinplate sheet is around ______
a) 0.5–1.5 mm
b) 0.15–0.5 cm
c) 0.5–1.5 cm
d) 0.15–0.5 mm
View Answer

Answer: d
Explanation: The term tinplate refers to low-carbon, mild steel sheet varying in thickness from around 0.15–0.5 mm with a coating of tin between 2.8 and 17 gsm (g m−2) (0.4–2.5 μm thick) on each surface of the material.

2. Tinplate is a combination of tin and steel.
a) True
b) False
View Answer

Answer: a
Explanation: The given statement is true. The combination of tin and steel imparts properties – good strength with excellent fabrication qualities like ductility and drawability, weldability, lubricity, lacquerability, non-toxicity and provides corrosion-resistance. Tin and steel together can undergo extensive deformation without fracture.

3. The temperature at which iron ore is heated is around ______
a) 2500°C
b) 1000°C
c) 1200°C
d) 1800°C
View Answer

Answer: d
Explanation: The iron ores used are generally hematite (Fe2O3) with some magnetite (Fe3O4). Commercial extraction of iron from its ores is carried out in blast furnaces, where a mixture of iron ores, solid fuel (coke) and fluxes (limestone and dolomite) are heated to around 1800°C. This results in the reduction of most of the iron oxides to metallic iron (m.p. ≈ 1200°C). Today, modern blast furnaces are capable of producing molten iron of near constant composition at high rates.
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4. In tinplate, steel serves as the base material.
a) True
b) False
View Answer

Answer: a
Explanation: The given statement is true. In tinplate, steel serves as the base material. The tin coating adheres sufficiently to the steel base so that it will withstand any degree of deformation that the steel is able to withstand without flaking.

5. The melting point of metallic ores is around ______
a) 1000°C
b) 1200°C
c) 1800°C
d) 800°C
View Answer

Answer: b
Explanation: The melting point of metallic ores is around 1200°C. Iron ores are generally heated at 1800°C, so that it reduces to metallic ores.

6. Pig iron from blast furnace contains ________ carbon.
a) 1.5%–2.0%
b) 2.5%–6.0%
c) 6.5%–8.0%
d) 3.5%–5.0%
View Answer

Answer: d
Explanation: The pig iron from a blast furnace contains 3.5%–5.0% carbon. Carbon is the most important alloying element for steel and affects the strength of cans. Carbon in higher concentration, when combined with manganese results in higher steel strength.

7. Pig iron from blast furnace contains ________ silicon.
a) 2.5%–3.0%
b) 0.3%–1.0%
c) 1.5%–2.0%
d) 0.1%–0.5%
View Answer

Answer: b
Explanation: Pig iron from blast furnace contains 0.3%–1.0% silicon. Hardness of pig iron decreases with increase in silicon. But, addition of a little amount of silicon improves the microstructure.
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8. Pig iron from blast furnace contains ________ manganese.
a) 5%
b) 10%
c) 1%
d) 2.5%
View Answer

Answer: d
Explanation: Pig iron from blast furnace contains up to 2.5% manganese. Manganese greatly contributes to increasing the hardness of the pig iron.

9. Pig iron from blast furnace contains ________ phosphorous.
a) 0.5%
b) 1%
c) 5%
d) 3%
View Answer

Answer: b
Explanation: Pig iron from blast furnace contains 1% phosphorous. Phosphorus generally contributes to the increase in eutectic temperature.
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10. Pig iron from blast furnace contains ________ sulfur.
a) 0.1%
b) 0.5%
c) 0.08%
d) 0.8%
View Answer

Answer: c
Explanation: Pig iron from blast furnace contains 0.08% sulfur. The low concentration of sulfur increases longevity. But a higher concentration acts as an impurity.

11. The thickness of iron slabs after rolling is around _______
a) 550 mm
b) 150 mm
c) 100 mm
d) 250 mm
View Answer

Answer: d
Explanation: These metalloids must be substantially reduced in the steelmaking stage, and this is commonly accomplished using a basic oxygen furnace. From the furnace, the steel is cast into ingots, which are subsequently rolled into slabs about 250 mm thick or, more commonly today, continuously cast into slab form.

12. The process of scale removal in manufacture tinplate is known as ______
a) pickling
b) leaching
c) flaming
d) charring
View Answer

Answer: a
Explanation: The process of scale removal in manufacture tinplate is known as pickling. The thick slabs are hot rolled down to about 2 mm and, during this process, substantial layers (0.01 mm thick) of oxides or scale are formed as a consequence of the steel being heated to elevated temperatures for rolling.

13. The final stage of thickness reduction is carried out by ________
a) roll pressing
b) screw pressing
c) hot rolling
d) cold rolling
View Answer

Answer: d
Explanation: The final stage of thickness reduction (typically 90% from about 2 mm to <0.2 mm) is carried out by cold rolling. The effects of cold rolling are to increase the strength and hardness of the steel, but this is done at the expense of ductility.

14. For reducing iron ore, oxygen furnace is used.
a) True
b) False
View Answer

Answer: a
Explanation: These metalloids must be substantially reduced in the steelmaking stage, and this is commonly accomplished using a basic oxygen furnace.

15. _______ is used for removing scales during the manufacture of tinplate.
a) Lithium hydride
b) Hydroboric acid
c) Orthophosphoric acid
d) Hydrochloric acid
View Answer

Answer: d
Explanation: The scale is removed by a process called “pickling,” which uses a dilute aqueous solution of acid (traditionally sulfuric acid but now mainly hydrochloric acid) near its boiling point. After pickling, the oxide-free strip is recoiled and coated with an oil to prevent rust formation and act as a lubricant in subsequent operations.

Sanfoundry Global Education & Learning Series – Food Packaging Technology.

To practice all areas of Food Packaging Technology, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Manish Bhojasia - Founder & CTO at Sanfoundry
Manish Bhojasia, a technology veteran with 20+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He lives in Bangalore, and focuses on development of Linux Kernel, SAN Technologies, Advanced C, Data Structures & Alogrithms. Stay connected with him at LinkedIn.

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