This set of Pulp and Paper Multiple Choice Questions and Answers (MCQs) focuses on “Coating”.
1. _________is the treatment or application of pigments, polymers, or other materials to one or both surfaces of paper.
Explanation: Coating can be applied on-machine or off-machine. On-machine coating has the obvious advantages associated with decreased handling of the paper. Off-machine has the advantages of providing greater flexibility to the system which includes the speed of coating.
2. Coatings are heavily applied at the _________
a) Size press
b) Dip roll
c) Applicator roll
d) Backup roll
Explanation: Coatings are applied at the size press or with a roll coater, air knife, or, the most common method, blade coater. Coating speeds are 3000 to 4000 ft/min for lightweight papers and 1200 to 1300 for board materials.
3. A _________ is primarily of a pigment and a binder and is designed to impart a good printing surface to the paper.
a) Size press
b) Backup roll
c) Printing coating
d) Coating components
Explanation: A printing coating is primarily of a pigment clay, TiO2, CaCO3, etc. and a binder like starch, protein, synthetic resin, etc. and is designed to impart a good printing surface to the paper.
4. A_________ is applied mainly for the sake of appearance or to act as a base for printing. Some examples are coated magazine and book stock.
a) Decorative coating
b) Printing coating
Explanation: Decorative coatings are the scratch resistant and give a bright colour to metal and plastic substrates.
5. _________ coatings are designed as barriers to liquids and vapors such as for frozen food containers.
Explanation:Functional coatings are designed as barriers to liquids and vapors such as for frozen food containers. Sometimes, pure polymers such as polyethylene are used to make laminates, milk cartons, etc. Other coatings are utilized to generate images such as in photographic papers, carbon paper, or carbonless papers.
6. A _________ is a H2O emulsion of a synthetic polymer (rubber or plastic). Latexes are utilized in paints, and many coatings are really much like paints.
Explanation: A latex is a H2O emulsion of a synthetic polymer rubber or plastic. Latexes are utilized in paints, and many coatings are really much like paints.
7. An _________ is a suspension of mutually insoluble materials.
Explanation: An emulsion’s a suspension of mutually insoluble materials. One of the materials’s dispersed as small droplets throughout the other. Milk’s an emulsion of fat and in water.
8. The coating usually consists of 3 categories of compounds which are _________
a) Clay, calcium carbonate, and titanium dioxide
b) Pigment, binder , and additives
c) Calendar, reel, and latex
d) Latex, emulsion, and alum
Explanation: The coating usually consists of 3 categories of compounds. The pigment, the binder, and additives. Pigments are materials such as clay, CaCO3, silicas, and other materials.
9. The _________ are classified as natural or synthetic. The natural _________ include starch, carboxylated soy protein, and casein, a white milk protein which contains phosphorus, which was the mainstay before 1955.
Explanation: The binders are differentiated as natural binders or synthetic binders. The natural binders include starch, carboxylated soy protein, and casein, a white milk protein which contains phosphorus, which was the mainstay before 1955. Starch can be treated in many methods to give a binder.
10. _________ coaters offer the advantages of low cost, the ability to coat 2 sides at once, and adaptability to on-machine coating.
Explanation: Blade coaters offer the advantages of less cost, the ability to coat 2 sides at once, and adaptability to on-machine coating. The disadvantages include an orange peel surface on the product, low speeds, the use of coatings with low solids and viscosity, and low coating levels.
Sanfoundry Global Education & Learning Series – Pulp and Paper.
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