Forest Utilization and Wood Technology Questions and Answers

Answer: C

The residual lignin is measured by the Kappa number.

In paper making, the Kappa number of a pulp is the volume of potassium permanganate solution consumed by a gram of pulp under set conditions. It indicates how much lignin is left after cooking and so how much bleaching the pulp will need.

Sulphidity and active alkali describe the strength and composition of the cooking liquor in the kraft process, not the pulp. Rigidity is a mechanical property.

Answer: A

The true statement is that quarter-sawn timber has a lesser tendency to warp (printed 'wrap').

Quarter-sawn boards are cut so that the growth rings run roughly at right angles to the face. Because wood shrinks about twice as much tangentially as radially, such boards shrink and swell less across their width and stay flatter, with less cupping and warping. They also wear more evenly.

That makes the other options false: quarter-sawn timber has less, not more, tendency to warp, it shrinks and swells less across the width, and it resists abrasion and wear better, which is why it is used for flooring.

Answer: B

The normal plywood sheet size is 2440 × 1220 mm.

The standard plywood panel is 8 feet by 4 feet, which is 2440 mm by 1220 mm, the size specified in Indian standards for commercial plywood and used worldwide.

1240 × 620 mm is roughly a quarter sheet, and 4840 × 2440 mm and 7240 × 4840 mm are far larger than standard panels.

Thickness varies with the number of plies, commonly from about 4 mm to 25 mm, but the 8 by 4 feet face size is the usual commercial standard, and other sizes such as 6 by 3 feet are cut from or made to order.

Answer: A

The sap displacement method for green poles is the Boucherie process.

In the Boucherie process, a preservative solution (such as copper sulphate) is fed under gravity or low pressure into one end of a freshly felled, unseasoned pole, and it displaces the sap, which flows out of the other end. It is suited to green poles and bamboos.

The Bethell (full-cell), Rueping and Lowry (empty-cell) processes are pressure treatments in closed cylinders, which need seasoned wood.

Answer: A

The answer is Cedar.

The Indian pulp and paper industry relies on fast-growing hardwood plantations and bamboo. Subabul (Leucaena leucocephala), poplar (Populus deltoides) and eucalyptus are the main farm-grown pulpwood species, harvested on short rotations.

Cedar, in India the deodar, is a slow-growing, valuable and durable construction timber of the Himalaya, rich in resin and oil, and is not raised or used as pulpwood.

Answer: B

There are two methods of seasoning wood.

Seasoning, the controlled drying of timber to the moisture content at which it will be used, is broadly classified as natural (air) seasoning, in which stacked timber dries in the open air under cover, and artificial seasoning, in which the drying is controlled, as in kiln, solar, chemical and electrical seasoning.

The longer lists of three, four or five methods come from counting the varieties of artificial seasoning separately; the basic division the question tests is into two.

Answer: C

The product is pulp.

Pulp is a lignocellulosic fibrous material prepared by separating the cellulose fibres of wood, bamboo, agricultural residues or waste paper, by mechanical or chemical means. It is a semi-finished product from which paper and board are then made.

Fine paper is a finished product made from pulp; wood is the raw material, not a product made from fibres; plywood is made by gluing thin veneers, not from separated fibres.

Answer: B

Hardiproof and Cuprinol are organic solvent type wood preservatives.

Wood preservatives are grouped into three types. Oil type preservatives, such as creosote, are oily liquids applied as they are. Water-soluble preservatives, such as copper-chrome-arsenic (CCA), are salts dissolved in water. Organic solvent preservatives dissolve the toxic chemical, for example copper or zinc naphthenate or pentachlorophenol, in a light organic solvent that evaporates after treatment, leaving the wood clean and paintable. Proprietary products such as Cuprinol and Hardiproof belong to this last group.

They are therefore neither oil type nor water soluble, and 'All of the above' is wrong.

Answer: D

Staypak is heat stabilized compressed wood.

Staypak, developed at the US Forest Products Laboratory, is made by compressing wood at a temperature high enough to make the lignin flow, so that the internal stresses relax and the compressed wood keeps its new density without springing back when it absorbs moisture. It is dense, hard and strong, and is used for tool handles and similar items.

Compreg (compregnated wood) is wood impregnated with resin and then compressed. Heat stabilized wood (staybwood) is heated without compression. Chemically modified wood, such as acetylated wood, is changed chemically rather than by compression.

Answer: A

Glulam is laminated wood.

Glulam, short for glued laminated timber, is made by gluing together several layers (laminations) of sawn timber with their grain running parallel along the length. This allows large, strong structural members, such as long beams and arches, to be made from smaller pieces, with defects spread out.

Core board (blockboard) has a core of wooden strips between veneers, and sandwich board has light core material between strong faces; both are panel products, not glulam. So 'All of the above' is wrong.