Science Fair Project on Wood

Do you want to create an amazing science fair project for your next exhibition? You are in the right place. Read the below given article to get a complete idea on wood: 1 Meaning of Wood 2. Diagnostic Features of Woods 3. Mechanical Properties 4. Types 5. Uses 6. Seasoning.

Contents:

1. Science Fair Project on the Meaning of Wood
2. Science Fair Project on the Diagnostic Features of Woods
3. Science Fair Project on the Mechanical Properties of Wood
4. Science Fair Project on the Types of Wood
5. Science Fair Project on the Uses of Wood
6. Science Fair Project on the Seasoning of Wood

Science Fair Project # 1. Meaning of Wood:

The term wood is applied to the secondary xylem regions of gymnosperms and dicotyledonous species. Woods are usually classified in two main groups — the softwoods and the hardwoods. The term softwood is applied to gymnosperm wood, that of hardwood to the dicotyledon wood. The two kinds of wood show basic structural differences, but they are not necessarily distinct in degree of density and hardness.

The gymnospermous wood, particularly of conifers, is relatively simple in structure, simpler than that of most of the dicotyledons. One of its outstanding features is the lack of vessels. The tracheary elements are imperforate and are mainly tracheids. Fiber tracheids may occur in the late wood, but libriform fibers are absent.

The early wood tracheids have circular bordered pits with circular inner apertures. The latewood tracheids have somewhat reduced borders with oval inner apertures. Axial parenchyma may or may not be present, but resin ducts appear as a constant features of coniferous wood. The rays of conifers are mostly one cell wide, occasionally bi-seriate and from 1 to 20 or even to 50 cells high.

In contrary, the wood of dicotyledons is more varied than that of gymnosperms. The wood of the primitively vessel-less dicotyledons is relatively simple, but that of the vessel-containing species is usually complex. Wood of the latter species may have both vessels and tracheids, one or more categories of fibers, axial parenchyma and rays of one or more kinds.

The use of wood for purposes of identification requires a very sound knowledge of wood structure and factors modifying that structure. In general macroscopic, microscopic characteristics of woods along with odor and taste were considered for diagnostic purposes.

For microscopic study of wood three kinds of sectional views of the wood was considered, these include, T.S. view, R.L.S. view, T.L.S. view. Often maceration of wood tissues were also made for detailed diagnosis of the wood.

Science Fair Project # 2. Diagnostic Features of Woods:

On the basis of several important diagnostic features the commercial woods may be identified to some extent.

The more important diagnostic features are mentioned here:

(i) Porous and Nonporous Woods:

The presence or absence, and the nature and arrangement of pores, serve as a ready means of classifying woods. The coniferous woods do not possess pores, and are known as nonporous woods, whereas the angiospermic woods possess numerous pores and are termed as porous woods. On the basis of the distribution of pores, the woods may be of two types—ring porous and diffuse porous woods.

In ring porous woods (e.g., ash, elm, oak, etc.) the pores are found to be arranged in concentric circles, the outer and inner portions of which differ with regard to the number and size of the pores. In diffuse porous woods (e.g., beech maple, walnut, etc.) the pores are small and nearly of the same size and are found to be scattered uniformly throughout the wood.

(ii) Early Wood and Late Wood:

In temperate regions, every year new wood is formed in a limited growing season, with the result definite growth layers develop, which shows two distinct areas within each layer.

The wood thus formed in the spring is called the spring wood or early wood, and that formed in winter is called the autumn wood or late wood. There is a sharp contrast between the late autumn wood and the early spring wood, and this makes the successive rings distinct.

The growth ring of a single year is called an annual ring and the number of these annual rings gives an indication of the age of tree. Annual rings of successive years may vary greatly in width. Wide rings are formed under favourable conditions of growth of the tree, and narrow ones are formed when conditions are unfavourable.

(iii) Sapwood and Heartwood:

The outer region of the wood which is of lighter colour is known as the sapwood, and this alone is used for conduction of water and salt solutions. The cells of this region are alive and physiologically active. In old trees the central region of the secondary wood is filled up with tannin and other substances which make it hard and durable.

This region is known as the heartwood. It looks black owing to the presence of tannins, oils, gums, resins, etc., in it. The vessels often become plugged with tyloses. The function of the heartwood is no longer conduction of water, but it simply gives mechanical support to the stem. The heartwood usually takes good polish and is used for cabinet work, furniture and other high grade wood-working industries.

(iv) Texture, Grain and Figure:

Texture refers to the relative size and quality of the various woods, while gram refers to their structural arrangement. Figure is applied to the design or pattern which appears on the surface of wood.

(v) Rays:

The rays are made of parenchyma cells that are oriented at right angles to the main axis of the stem. They vary greatly in width, height and arrangement.

Science Fair Project # 3. Mechanical Properties of Wood:

Wood possesses some important mechanical properties which either alone or in combination, determine its usefulness and suitability for various purposes. These properties may differ in different species. The mechanical properties enable the wood to resist various external forces which tend to change its shape and size and produce deformations.

The important mechanical properties of wood are mentioned here.

A. Strength:

The strength is restricted to the ability to resist certain definite forces which may be termed—crushing strength, tensile strength, shearing strength and cross-breaking strength.

They are as follows:

(i) Crushing Strength:

It is the resistance offered to forces that tend to crush wood.

(ii) Tensile Strength:

It is the resistance to forces that tend to pull wood apart.

(iii) Shearing Strength:

It is resistance to those forces which tend to make the fibres slide past one another.

(iv) Cross-Breaking Strength:

This is the resistance to forces which cause the beams to break, and all the above-mentioned forces are involved.

The strength of wood is the most important property in determining the value of any species for structural purposes. It is a very variable property, and is influenced by the density of the wood, the moisture content, the presence of defects and many other factors.

Suitability figures for eight different properties have been calculated by taking into consideration the various strength functions of both green and seasoned timber as shown in the table.

B. Stiffness:

It is the measure of the ability of wood to resist forces that tend to change its shape.

C. Toughness:

It is referred to the ability of wood to absorb a large amount of energy, and so resist repeated, sudden sharp blows or shock.

D. Hardness:

It is the measure of the power of wood to resist indentations, abrasion and wear.

E. Cleavability:

It is an expression of the ease with which wood can be split.

Science Fair Project # 4. Types of Wood Found in India:

(i) Babul:

Acacia nilotica (Linn.) Del.; Syn. A. arabica Willd.; Trade name—Babul; Hindi—Babul, kikar; Bengali—Babul; Hindi—Punjab and Uttar Pradesh—Kikar, Gujarati—Baval; Telugu— Nallatumma; Tamil—Karuvelev, Kannada—Jaali, gobbli; Malayalam—Karivelan; Family—Mimosaceae.

The sapwood is yellowish-white and usually wide. The heart-wood when freshly cut, is a pinkish or old rose colour, but it darkens on exposure to a dull red or reddish brown. It is often mottled with darker streaks. The wood is dull and without taste or smell, hard, fairly close-textured and with straight or slightly twisted grain.

There are several varieties of babul. The two best known are the telia and kauria varieties, the wood of the former having a better reputation than the latter.

Seasoning:

Babul is a wood which can be air-seasoned with fairly good results if care is taken. One year is sufficient to air-season babul boards up to 2 in. in thickness. It can be kiln-seasoned without difficulty.

Strength:

Babul is an extremely strong, hard and tough wood. It is nearly twice as hard as teak and has a very good shock resisting ability.

Durability:

The sapwood is not durable. The heartwood is durable in most situations but not to the same degree as teak and sal.

Working Qualities:

An easy wood to convert and to saw when green, but it becomes harder and tougher when seasoned. It works well by hand, and machines and finishes to a good surface. It takes a fair polish but requires careful filling.

Uses:

It is popular for parts of carts (body work, spokes, naves, axles, felloes, yokes and shafts), and for agricultural implements such as ploughs, harrows and clod-crushers. It is a useful tool handles wood but not for all types of handle, and it can be used for tent pegs.

It can be described as one of the best Indian utility woods where hardness and toughness are required. It is a good turnery wood.

Sources of Supply:

Babul is usually available in small logs only, but in some districts larger logs are available. It is found throughout the drier regions of North, Central and South India.

(ii) Simul:

Bombax ceiba L.; Syn. Salmalia insiginis (Wall.) Schott & Endl.; Hindi—Semul; Sanskrit.

Salmali, rakta-pushpa’, Bengali—Simul, roktosimui, Marathi—Saur, simlo; Gujarati—Sawar, simalo; Telugu—Booruga, konda-buruga’, Tamil—Mullialava’, Kannada—Booruga’, Malayalam— Pula-maram; Oriya—Bour; Garo—Panchu; Mundari—Edelsong’, Family—Bombacaceae.

A large tree found in the Western Ghats, Assam and the Andaman Islands. The wood is very soft creamy white or pale pink timber, very light in weight and with large open pores.

Seasoning:

Quick drying can be achieved by exposing freshly converted timber directly to the drying action of the sun and wind or by kiln-seasoning. If air-seasoning is to be done, the best method is to stack the freshly sawn stock in a vertical position against a building or railing with the planks facing the sun.

The boards should be turned from time to time so that both surfaces are exposed, kiln-seasoning is the surest and best method of drying simul.

Uses:

The wood is used for matches, packing cases, penholders, veneers and ply-wood.

Wood is most widely used in match industry, especially for match boxes. Suitable for shingles, canoes, toys, scabbards, cooperage, bush handles, tea-chest plywood and picture frames. Also used for cushioning mine-props and for inside portions of opium chests. Floss used for stuffing life belts, mattresses, cushions and pillows, upholstry and quilts. Tree yields a gum called mocharus.

(iii) Albizia:

There are several common commercial Albizia woods. The best known is perhaps Albizia lebbeck (Linn.) Benth.; the others A. odoratissima, A. procera, and A. stipulata.

(iv) Red Cedar:

Toona ciliata Roem.; Eng. Cedrela tree. Red cedar; Hindi—Toon- Sanskrit—Nandivriksha, tunna: Hindi and Bengali—Tun, mahanim; Marathi—Kurut, Tamil—Santhanavembu, tunumaram; Telugu—Nandichettu; Kannada—Mandurike’, Malayalam—Malarveppu, Assam— Poma-, Family—Meliaceae.

A tree cultivated in the Punjab, Assam, Bihar, the Western Ghats, Maharashtra, Madhya Pradesh and the Nilgiris.

Description of Wood:

The wood is a pinkish brick red, when freshly cut, toning to a light brownish red on exposure. The wood is a light weight, and usually straight grained timber. The wood has a distinct cedar like smell.

Seasoning:

Toon is a fairly easy wood to air-season if care is taken with the stacking. Kiln- seasoning can also be done.

Strength:

Toon is a timber of only moderate strength qualities. Hill toon is strongest and has about 80% the strength of teak.

Working Qualities:

Toon is one of the easiest of Indian woods to saw and work. If properly finished and filled, it takes a very good polish. It makes up into a good type of plywood. It makes high quality congealated wood.

Uses:

The wood is used for furniture, tea-chests, shuttles and picking sticks which are used in the textile industry, and cigar boxes.

(v) Walnut:

Juglans regia Linn; Eng. English walnut, Persian walnut; Hindi—Akhrot; Family— Juglandaceae. Found in Kashmir, Himachal Pradesh, the Khasia hills and in the hills of Uttar Pradesh.

Indian walnut varies considerably in colour, sometimes being a dull grey, while other wood may be a dark brown with even darker markings. It is relatively light wood for its strength and it works very easily and finishes to a fine surface.

Its most important quality, however, is that, when once dried it does not shrink, swell or split. This, combined with its lightness, strength and good working qualities gives it pre-eminence as a wood for rifle parts, gun stocks, high class cabinet making, and delicate carvings.

Seasoning:

Walnut wood seasons slowly and springs considerably while drying out, but apart from this, it is a model wood in so far as seasoning is concerned, both in air-drying and kiln-drying. Green conversion, followed by stacking under cover with a good air circulation is the method of seasoning recommended.

Strength:

For its weight, walnut is a relatively strong wood. It is about 85% the weight of teak and in shock resistance is about equal to teak.

Working qualities:

An extremely easy and pleasant wood to saw and work to a fine finish. It takes an excellent polish and needs very little filling.

Uses:

The wood is used for musical instruments and cabinet work. Used extensively in Kashmir and North India for carving. Well known as an excellent veneer and plywood timber. It is also used for gun stocks.

(vi) White Willow:

Salix alba Linn.; Eng. White willow; Hindi—Bis; Kashmir—Vivir, Punjab—Bis, madnu, bhushan Family—Salicaceae.

A small tree, found in the North-Western Himalayas and in the valley of Kashmir. The twigs are used for making baskets. Cricket bats are made of the wood.

Used also for house building, match-boxes and splints, shoes, tool-handles, agricultural implements, boats, boxes, combs and toothpicks; suitable for paper pulp and charcoal making.

(vii) Mulberry:

Moms alba, Linn; Eng. White mulberry; Hindi—Tuf, Family—Moraceae. A tree, native of China. In India, it is grown in Punjab, Uttar Pradesh, Kashmir and the North-Western Himalayas. It is also cultivated in Karnataka state for silk worm cultivation.

Description of the Wood:

The sapwood is white and sharply delimited from the heartwood, which is a bright yellowish brown when freshly cut. No odour or taste. Straight-grained and of rather open medium coarse texture.

Seasoning:

The best results have been obtained by storing the logs for some months before final conversion. The wood can be kiln-seasoned without difficulty. In practice, the most of the mulberry used in Punjab is used in a green state by the sports goods manufacturers. The timber is converted green, steam bent, and the dried out in a bent form tightly held in a clamp.

Strength:

It is approximately the same in weight as teak, and in shock resistance, shear and hardness it is considerably higher than teak.

Uses:

The primary use is for sports goods, for which purpose it is eminently suitable. It is used mainly for the manufacture of hockey sticks. It is also used for tennis rackets, badminton and squash rackets, presses, cricket stumps, etc.

Also suitable for house-building, agricultural implements, furniture, spokes, poles, shafts, bent parts of carriages and carts and for turnery. Bark is used for paper making; also yields a textile fibre.

(viii) Deodar:

Cedrus deodara Loud; Eng. Deodar; Hindi—Deodar, Diar, Family—Pinaceae. A tall evergreen tree found in the North-Western Himalayas from Kashmir to Garhwal.

Description of the Wood:

It is of light yellow-brown colour and possesses distinctive odour, it is a medium weight wood which is very sturdy in use and durable. It is usually even-grained and of medium to fine texture, but the presence of large knots is a common feature.

Seasoning:

It is an easy wood to air-season. It can also be kiln-seasoned.

Strength:

Deodar is the strongest of the Indian conifers. Its weight is 20% less than teak and its strength is also about 20% less.

Working Qualities:

It is an easy timber to saw and work to a smooth finish.

Uses:

The timber is used for construction work and for railway sleepers. It is also suitable for beams, floor boards, ports, window frames, light furniture and shingles.

This is strongest of Indian coniferous woods, also used for doors, furniture, packing cases, masts, spars and also for wooden bridges. Wood yields an oleoresin and a dark coloured oil used for ulcers and skin diseases.

(ix) Himalayan Spruce:

Picea smithiana (Wall.) Boiss. ; Eng. Himalayan spruce; Hindi—Bajur, North West Himalayan region—Rai, rau, re, kachal, salla, tos’, Jaunsar, Garhwal and Kumaon-Roi, rhai, ragha, morinda; Trade—Spruce; Family—Pinaceae.

A tree commonly found in the Western Himalayas. The wood is used for construction work, railway sleepers, cabinet making, packing cases and wood pulp.

One of the most useful timber trees of the Western Himalayas. Wood is used for planking, general fittings and joinery, rough furniture, tea-boxes and packing cases. This is one of the best light boxwood of India. Wood is suitable also for match boxes, battery separators, for fence posts, transmission poles, piles and newsprint manufacture.

(x) Pine Wood:

Pinus roxburghii Sar; Eng. Long-leaved pine; Hindi—Chir, Salla; Family—Pinaceae.

An evergreen coniferous tree. It is found in the Western and Eastern Himalayas. The wood is used for construction work, railway sleepers, packing cases, furniture and in match industry.

Pinus merkusii Jungh & de Vries. A tree. The wood is very resinous with reddish-brown heartwood and yellow sapwood. It is used for building purposes and general carpentry.

Pinus waliichiana A. B. Jackson; Eng. Indian blue-pine; Hindi—Kail, Chil. A coniferous tree. The wood is used for pencils, penholders, splints, match boxes, construction work, railway sleepers, and furniture. Also used for shingles, packing cases, constructional work and house fitments. It is a good wood for pattern making, cores for laminboards, drawing boards, and planetables.

(xi) Indian Rosewood:

Dalbergia latifolia Roxb.; Eng. Indian rosewood; Vema. Kali Shisham; Sanskrit—shishapa; Bengali—sitsal, swetasal; Mamthi-Shisham, siswa’, Gujarati—Shissam, kalaruk, Telugu— Cittegi, irgudu- Tamil—Itti, karundorviral, Kannada—todagatti, Malayalam—Itti, colavitti, Oriya—Sisua-, Trade—Indian Rosewood; Family—Papilionaceae.

A large deciduous or nearly evergreen tree with cylindrical, fairly straight bole and full rounded crown, found in the sub-Himalayan tract of Eastern Uttar Pradesh, Bihar, Orissa and central western and southern India. It attains its maximum development in the southern region of western ghats, where trees 130 ft. high up to 20 ft. in girth and 70 ft. clear bole are sometimes found. The minimum exploitable size is 6 ft. girth.

The sapwood is narrow and pale yellowish white in colour, often with a purple tinge. The heartwood ranges in colour from golden brown through shades of light rose, purple with darker streaks, to deep purple with rather distant, nearly black lines, darkening with age. It is fragrant, heavy, narrowly interlocked grained and medium coarse-textured. The timber is stronger and much harder than teak.

Indian rosewood ranks among the first wood for furniture and cabinet work. It is a valuable decorative wood suitable for carving and ornamental ply-boards and veneers. It is specially useful for pattern-making, calico printing blocks, mathematical instruments and screws.

It is also used for gun carriage wheels, ammunition boxes and army wagons, pulleys, handles, shelves, decorative carriage parts, temple chariots, boat knees, agricultural implements, combs, razor handles and brush backs. Carefully selected and manufactured Indian rosewood ply-boards satisfy aircraft specification.

(xii) Sissoo:

Dalbergia sissoo Roxb.; Eng. Sissoo; Verna. Shisham; Sanskrit—Shinshapa, aguru; Hindi— Shisham, sissu, sissar, Bengali—Shisu, Gujarati—tanach-, Telugu—Errasissu, sinsupa’, Tamil—Sisu ittv, Kannada—Agaru, biridr, Malayalam—Irail; Oriya—simsapa- Punjab— Tali, shisham; Marathi—Sissu; Trade—Sissoo, Shisham; Family—Papilionaceae.

A deciduous tree, often with crooked trunk and light crown. Normally the tree attains a height of about 100 ft., a girth up to 8 ft. and a clear bole up to 35 ft. It occurs throughout the sub- Himalayan tract from Ravi to Assam, ascending up to 5,000 ft. It is extensively cultivated in Punjab. Uttar Pradesh, Bengal and Assam. No other timber tree, except teak is cultivated to a greater extent.

The sapwood is white to pale brownish white in colour and the heartwood, golden brown to dark brown with deep brown streaks becoming dull on exposure. It is heavy, narrowly interlocked grained and medium textured. It can be air or kiln-seasoned.

However, kiln-seasoning enhances the value of timber as the colour darkness and the difference between lighter and darker bands gets intensified. The wood can be converted into ornamental veneers or commercial plywood of good quality.

Sissoo (Shisham), is a high class furniture and cabinet wood widely used throughout north India. On account of its great strength, elasticity and durability, it is highly valued as constructional and general utility timber and is used for all the purposes for which Indian rosewood is employed in the south.

It is esteemed also for railway sleepers, musical instruments, Charpai legs, hammer handles shoe heels, hookah tubes and tobacco pipes.

Carefully selected and manufactured plywood logs satisfy the specifications prescribed for aircraft, and for this purpose, the wood from trees, growing on canal banks and in plantations is considered to be the best. Sissoo wood is suitable for making laminated skiis. It can be worked into decorative ornamental carvings.

(xiii) Andaman Redwood:

Pterocarpus indicus Willd; Eng. Andaman redwood; Verna. Padauk. It is a large and lofty tree found in the Andaman islands. Sapwood is small. Heartwood is dark-red, close-grained, moderately hard with a slight aromatic scent.

It is durable and not attacked by white ants. When thoroughly seasoned it is unaffected by alternate dryness and moisture of the atmosphere. It seasons well, works well and takes a very fine polish. It is used for furniture, carts, guncarriages, and other purposes, and is said to be the most useful wood in the Andamans, and where it grows to an enormous size.

(xiv) Indian Kino Tree:

Pterocarpus marsupium Roxb. Sanskrit—Pitasara; Hindi—Bijasal; Bengali—Pitshal; Marathi—Asan, bible; Gujarati—Biyo: Telugu—Yegi, peddagi; Tamil—Vengai; Kannada— Honne, bange; Malayalam—Venga; Oriya—Byasa-, Trade—Bijasal; Family—Leguminosae.

The wood is used chiefly for building purposes, such as doors, window frames, rafters, beams and posts. It is also used in railway carriages, wagons, carts, boats, ships, electric poles, pit-props in mines, agricultural implements, drums, tool handles, camp furniture, mathematical instruments, picture frames, combs, and parts of textile looms. It is a very important timber in peninsular India.

(xv) Red Sandalwood:

Pterocarpus santalinus Linn.; Eng. Red sandalwood; Verna. Rukhto-chandan; Sanskrit— Raktachandana; Hindi and Bengali—Raktachandan, lalchandan; Marathi—Tambada chandana; Gujarati—Ratanjali; Telugu—Agarugandhamu, raktagandhamu; Tamil—Atti, sivappu chandanam; Kannada—Agaru, honne, kempugandha; Malayalam—Patrangam; Oriya— Raktachandan-, Trade—Red Sanders.

A small tree of South India, chiefly found in Cuddapah, North Arcot, and the southern portion of the Karnul district. It favours a dry, rather rocky soil, and a hot fairly dry climate.

Sapwood is white. Heartwood is purplish-black dark orange-red when fresh cut, extremely hard, the shavings giving a blood red-orange colour. It is used for building and for turning, and is said to be much prized because it is not subject to the attacks of white ants. It is much used for carvings in Andhra Pradesh especially at Tirupati.

Wood is highly prized for house posts; also used for agricultural implements, poles, shafts and bent rims of carts, picture frames, boxes and other joinery work. In Japan, it is used for a musical instrument called Shamisen. Wood is ground and used for dyeing wool, cotton and leather, and staining other woods; santalin is the colouring principle.

(xvi) Ebony:

Diospyros ebenum Koenig.; Eng. Ebony; Verna. Abnus’, Windx—Ebans, abnus; Telugu-

Nallavalludu-, Tamil—Tumbi, karunkali; Kannada—Karemara; Malayalam—Karu, vauari; Oriya—Kendhu, Trade—Ebony.

It is a moderate to large sized evergreen tree with a dense crown, sometimes attaining a height up to 80 ft. and a girth of 7 ft. The girth of heartwood is not more than 4 ft. It is found in the dry evergreen forests of Deccan, Karnataka, Coimbatore, Malabar, Cochin and Travancore. It prefers well-drained rocky soil and grows well on sandy loam. It is found sparsely scattered in the forests in mixture with other trees.

This is perhaps the best ebony yielding tree and the only one which yields jet black heartwood without streaks or markings, the true ebony of commerce, D. ebenum is not very commonly found in India, nor do the trees, where they occur, attain any large size. Only limited supply of ebony is available in the area of its occurrence.

The sapwood is light yellowish grey, often streaked with black. The heartwood is jet black, rarely with a few dark or light brown or golden streaks. It has a metallic lustre when smoothed. It is heavy, straight-grained or somewhat irregular or wavy-grained, fine and even-textured.

Ebony is difficult to season. It is best to convert the green logs to the smallest size permissible and to store them under cover, well protected from hot winds.

The heartwood is resistant to attack by insects and fungi. It is very durable. The value of this wood depends on its intense blackness, working quality and the high finish it takes. It is difficult to work, especially when dry, but finishes to a glossy surface. It requires little hand finishing and takes a high lasting polish. It is one of the most valuable woods in the fancy wood market.

It is used for ornamental carving and turnery, and for special purposes in decoration. It is used for veneers, inlaying, musical instruments, sports goods, mathematical instruments, piano keys and caskets.

Diospyros virginianum Linn, is widely used for weaving shuttles and is the standard wood for the heads of golf clubs.

(xvii) Saffron Teak:

Adina cordifolia Hook, f.; Eng. Saffron teak; Verna, Haldu, Hindi—Haldu, Bengali— Petpuria, dakom-, Marathi—Heddi; Telugu – Pasupukadamba’, Tamil and Malayalam— Manjakadamba-, Kannada—Arsintega, yettega; Trade—Haldu; Family—Rubiaceae;

This makes an important Indian timber, used for a great variety of purposes; Pearson and Brown (1932) state that it is one of the best turnery wood in India and that selected pieces are attractively figured. The wood is commonly used for carvings, construction work, flooring and for railway carriages.

Timber is easy to saw, seasons well and takes good polish; durable under cover, resistant against subterranean termites, but highly susceptible to drywood termites. Haldu is accepted as grade I commercial and moisture-proof plywood timber.

Wrapping, writing and printing paper is manufactured from the wood pulp. secularization

(xviii) Teak:

Tectona grandis Linn.; Eng. Teak; Hindi—Sagaun; Sanskrit—Saka; Bengali—Segun-, Marathi—sag, sagwan; Gujarati—Telugu—Adaviteeku, teeku; Tamil—Tekkumaram, tekku, Kannada—Jadi, sagwani, Malnyalam—Thekku, tekha; Onya—Singuru-, Assam—Chingjagu; Lepcha—Ripnyot, Family—Verbenaceae.

A large, deciduous tree, indigenous to both peninsulas of India. In Western India it does not extend far beyond the Mhye. In Central India it attains its northern most point in the Jhansi district, and from that point the line of its northern limit continues in a south-east direction to the Mahanadi river in Orissa.

It is found wild in Assam. It is, however, cultivated throughout Bengal, Assam and Sikkim, and in North-West India without difficulty as far as Saharanpur. The forests richest in large timber on the west side of the Peninsula are the Travancore, Anamally, Wynad, South-west Karanataka and North Kanara forests. In the centre of the Peninsula the Godavary forests are most compact and valuable.

Structure and Utility of Wood:

Sapwood white and small; the heartwood when cut green, has a pleasant and strong aromatic fragrance and a beautiful dark golden yellow colour, which on seasoning soon darkens into brown, mottled with darker streaks. The timber retains its fragrance to a great age, the characteristic odour being apparent whenever a fresh cut is made.

It is moderately hard, exceedingly durable and strong, does not split, crack, warp, shrink or alter its shape when once seasoned; it works easily, takes a good polish.

Teak owes its chief value to its great durability, which is ascribed, probably with justice, to the circumstance that it contains a large quantity of fluid resinous matter which fills up the pores and resists the action of water. (At the Karli caves near Poona the teak-wood-work, two thousand years old, seems perfectly good at the present day).

The many uses of teak are well known. In India it is highly prized for construction, ship building, and for making sleepers and furniture.

Wood is very durable and resistant to fungi. It is used for poles, beams, trusses, columns, roofs, doors, window frames, flooring, planking, panelling, stair cases, and other constructional work. It is one of the best timbers for furniture and cabinet making, wagons and railway carriages.

Due to its better shape-retention ability, teak is popular in marine constructions and is a class by itself for boat and ship-building, particularly for decking. On account of its resistance to chemicals, teak articles are used in chemical industries and for making laboratory bench-tops; suitable for casks and vats for shipping corrosive liquids and for storing vegetable oils, fruit syrups, chutneys, etc.

Teak is employed for sound-boards of musical instruments, keys, etc., and for different grades of plywood. Wood waste in the form of wood-shavings and sawdust is used for chip-boards, fibre-boards and plastic-boards.

(xix) Sal:

Shorea robusta; Eng. Sal tree; Hindi—Sai, Bengali and Hindi—Sal, sakhu; Marathi and Gujarati—Ral; Telugu—Gugal; Tamil—Kungiliyam; Kannada—Kabba’, Malayalam— Maramaram; Oriya—Sal, sagua, Punjab and Haryana—Sal; Lepcha- Taksal-Kung;Assam—Sal, bohal. Trade—Sal; Family—Dipterocarpaceae.

A large gregarious tree, often covering certain interrupted tracts without the existence of connecting patches. It occurs along the base of Tropical Himalayas from the Sutlej to Assam, in the eastern districts of Central India, and on the Western Bengal Hills.

Structure and Utility of Wood:

The sal, one of the most valuable timber trees in India, has a distinct sapwood which is small in amount, whitish and not durable. The heartwood is brown in colour, finely streaked with darker lines, coarse grained, hard, strong and tough, with a remarkably fibrous and cross-grained, structure.

The fibres of successive concentric strata do not run parallel, but at oblique angles, to each other, so that when the wood is dressed the fibres appear interlaced It does not season well, but warps and splits in drying, and even when thoroughly seasoned, absorbs moisture with avidity in wet weather.

During the process of seasoning, it dries when first cut, and evaporation goes on afterwards with extreme slowness. Sal, when once thoroughly seasoned, stands almost without a rival, as a timber, for strength, elasticity, and durability, which qualities it retains without being sensibly affected, for an immense length of time. Average weight of the seasoned sal about 35 lb. per cubic foot (Brandis; Gamble).

The timber is the one most extensively used in Northern India. It is in constant request for piles, beams, planking and railing of bridges, doors, and window posts of houses, for the bodies of carts, and above all, for railway sleepers.

In Assam it is favourite wood for boat-building, and in the hills of Northern Bengal where it is found, perhaps, of the largest size available, the trunks are hollowed out into canoes.

Owing to the fact that when unseasoned it is not floatable, difficulty is experienced in most sal forests in getting the timber out of the forests in log. This is, however, overcome by floating the logs either with the assistance of the boats or with floats of light wood or bamboos (Gamble).

Sal wood ranks with teak and deodar as one of the best sleeper woods in India; also used in form of bellies and poles. After treatment, the poles are suitable for overhead electric, telegraph and telephone lines.

As domestic timber it is used for beams, scantlings, rafters and floors; also used for piles, mine work and pit props, bridges, dug-out boats, carriages and wagon building, spokes, fellows and hubs of wheels, agricultural implements, tool-handles, tent pegs, liquid storage vats, and beer and oil casks.

Agricultural implements is a term of rather wide application but it refers in the main to such appliances as ploughs, harrows, rollers and clod crushers. A strong, hard tough timber is required for this type of work. Acacia nilotica (Babul), Anogeissus latifolia (axle wood), Syzygium cumini (Jaman), Grewia tiliifolia (Dhaman), Shorea robusta (Sal), Xylia xylocarpa (Irul), etc., are used for agricultural implements of different kinds.

Woods for helves and tool handles must be strong and tough and must also possess great shock resisting abilities. Dalbergia spp. (Shisham), Grewia spp. (Dhaman), Diospyros spp. (ebony), etc., are recommended for this purpose.

Timber used in all small boats and large ships is subjected to very great strains, and is often employed under circumstances which tax its durability to the utmost. For this reason any timber used for ship and boat-building should be strong, elastic, durable and free from defects.

Tectona grandis (Teak—Sagaun) is the best ship-building timber in the world, due to its relatively small co-efficient of expansion and contraction and to its durability. The other recommended timbers for this purpose are—Acacia nilotica (Babul), Dalbergia spp., Dipterocarpus spp., Shorea spp., Xylia spp., Grewia spp., Moms spp., Terminalia spp., Bombax spp., etc.

There is a considerable demand in India for boot and shoe lasts, and recently demand for shoe heels, and especially ladies shoe heels, has grown enormously. For boot lasts and shoe heels, a tough wood which is not too hard is required.

In addition, the wood must be able to stand repeated nailing. The important woods used for the purpose are—Dalbergia sissoo (Shisham), Gardenia spp., Mitragyna parviflora (Kaim), Mangifera indica (Am), etc.

The various parts of a cart or carriage are subjected to different kinds of stresses and strains, and require different qualities of wood for real efficiency. The important woods recommended for various parts of the carts are—Dalbergia spp., Shorea spp., Dipterocarpus spp., Syzygium spp., Acacia spp., Grewia spp., Anogeissus spp., Terminalia spp., and several others.

Constructional woods are those timbers used for superstructures, which include all parts of houses and buildings, bridges and similar structures not actually in contact with water or the earth. For this purpose a timber should be strong and durable.

Lightness of wood is sometimes an asset if strength and durability are not sacrificed. Floor and wall planking should be non-warping and non-shrinking and the wood for interior work and panels should be ornamental.

There are three very important woods which stand out above all others as building timbers. These are—Tectona grandis (Teak—Sagaun), Shorea robusta (Sal) and Cedrus deodara (Deodar). The other important timbers used for this purpose are—Acacia spp., Toona ciliata (toon), Dalbergia spp., Mangifera indica (Am), Pinus spp., Terminalia spp., Xylia spp.

Cooperage or barrel-making consists of two types, ”tight cooperage”, i.e., barrels used for liquids, and “loose or slack cooperage” used for dry goods like cement. The oaks, dhaman are used for tight cooperage for beer and liquor casks. Bombax ceiba (Simul), mango spruce, etc., are used for slack cooperage.

The qualities necessary to make a good pole are that it should be straight, i.e., without crooks and bends, that it should not split or crack excessively, and that it should have the required strength for the work it has to do. The woods used in India for use as electrical transmission poles are—Pinus roxburghii (Chir), Shorea robusta (Sal), Tectona grandis (Teak), Cedrus deodara (Deodar), Terminalia tomentosa (Laurel), etc.

Dalbergia sissoo (Shisham) in North India, and Dalbergia latifolia (Rosewood) in South India, are the most popular woods for calico-printing blocks. Sissoo (Shisham) is considered to be excellent for the purpose. Toona ciliata (toon) and Tectona grandis (teak) are also sometimes used. Tamarindus (Imli) is also said to be good for printing by the Indian method.

For high class furniture, cabinet-making and decorative panel work, there are several very ornamental and excellent woods in India. The chief characteristics required for these uses are non-liability to crack and split, retention of shape, ease of working and good colour figure and grain.

The most commonly used and recommended timbers for the purpose are Albizia spp., Toona ciliata (toona), Dalbergia spp., Juglans regia (walnut), Tectona grandis (teak), Terminalia tomentosa (Laurel), etc.

Artocarpus spp., is wildly grown and commonly used for making furniture in South India especially in Kerala it is a valuable wood. It is also preferred in temple works in Kerala.

A good match wood for splint manufacture must be soft, straight- grained, white and cheap. India possesses many woods which are suitable for box making and splints. The woods are—Bombax ceiba (simul), Anthocephalus indicus (kadam), Salix spp., etc.

The better class of mathematical instruments such as set squares, rulers, etc., are usually made of Buxus wallichiana (box wood), Juglans regia (walnut) and Aesculus indica (horse chestnut), but cheaper instruments intended for school use are often made of Adina cordifolia (Haldu), Toona ciliata (Toon), Gardenia spp., etc. For set square and ruler edgings, good quality hardwoods such as rosewood sissoo and ebony are most frequently used.

In India, many woods are used for making musical instruments as tanpura, sitars, violins, etc., teak, toon, sissoo, mulberry, haldu being among the commonest. For sitars, teak is used for the long neck and deodar or shisham for keys. Toon is almost universally used for the bodies. For banjos, teak is most commonly used. For drums, mulberry, sissoo, siris etc, are used. Canarium euphyllum (Dhup) is used for guitars.

Wood for these purposes must be light, easily worked and cheap. They must have good nail-holding power and should preferably be of whitish colour. Tea is now generally packed in plywood chests, which are strong, light and cheap. Hollock (Terminalia myriocarpa) and hollong are used for making good plywood tea chests.

The commonest Indian woods for packing cases and boxes are—Dalbergia spp., toon, teak, mango, siris, kadam, Terminalia chebula, Pinus spp., etc., Cigar boxes are used made in South India of Toona ciliata, Melia azedarach, etc. Terminalia chebula is a popular wood in South India for coffee boxes, while poplar (Populus spp.) is much used in Kashmir for fruit crates.

Amongst the timbers used in India for pencil making may be mentioned Cypress, blue pine or kail, simul, toon, Salix tetrasperma, Melia spp., etc. Pen-holders may be made of Haldu, Gardenia spp., Kaim, etc.. Spruce and fir are used in North India for cheap pen-holders.

No very special qualities are required for picture framing, so long as the wood used is well seasoned and not liable to warp. There are two distinct types of picture framing, one in which the wood is used in its natural state, either polished or waxed, and the other in which the framing is painted or covered with a plaster composition which is moulded to the form required and covered with gilt or other colouring media.

For the former type of framing and steady ornamental wood is suitable, the most commonly used being teak, sissoo, rosewood, ebony and haldu. For cheaper frames, in plain moulded form or painted, light conifer woods such as fir and spruce are the best. School slate frames can be made from a variety of woods, e.g. Trewia nudiflora (gutel), Terameles nudiflora (maina), Terminalia chebula, Mangifera indica (Am), spruce and fir, etc.

The qualities required of a wood to be in railway carriage and wagon work are that it should be sufficiently strong and durable. It should be free from bad seasoning defects, and it should be available in sufficient quantities. Teak complies with this specification better than any other timber, and for this reason teak is the main timber used by’ all the railway wagon and carriage works in India.

The other important timbers used for this purpose are—Shorea robusta, Pterocarpus spp., Adina cordifolia, Cedrus deodara, Dalbergia latifolia, Toona ciliata. Acacia nilotica, Dipterocarpus spp., Pinus spp., and several others.

The woods most commonly used are—sal, deodar, teak, pyinkado, and bijasal.

Walnut (Juglans regia) is the chief timber used for the manufacture of rifle work all over the world, as it stands up exceptionally well when worked to a fine finish on high speed cutting and drilling machines. The wood is also very steady and is not prone to excessive shrinking, swelling, warping or splitting, once it is properly seasoned.

The subject of shuttles is a very important one in India. All cotton, jute, wool and other textile mills use wooden shuttles in large quantities. The important wood which may be used for making shuttles are—Diospyros melanoxylon (ebony). Gardenia latifola. Acacia nilotica, Mitragyna parviflora, Dalbergia latifolia, Dalbergia sissoo, etc.

Billiard cue shafts in India are made of Diospyros melanoxylon (tendu), Grewia tilaefolia (dhaman), Polyalthia fragrans. For the butts of cues ebony, Hardwickia pinnata and Dysoxylum glandulosum are used.

More than 200 manufacturers in India are involved in the production and export of world- class sports goods. These goods are of such superior quality that over 70 countries import from India. Professional players use them in national, international and even Olympic tournaments.

There are several good reasons for the tremendous popularity of Indian sports goods abroad: excellent quality, superb finish, carefully selected raw material, enhanced durability. And to top it all master craftsmanship from India, the land of traditional skills.

Cricket bats are made of Salix spp. (williow). Populus spp; has also been used for cheap types of bat.

Indian cricket bats have scored many a century for the world champions. Made from strong Kashmir willows {Salix spp.), the bats are designed for force and flexibility.

Golf clubs are made of Terminalia spp., Grewia spp., Anogeissus spp., and Pyinma.

Hockey sticks are made of Morus alba (mulberry). Hockey sticks from India are known the world over for their balance and strong drive.

The timbers employed for the skis are Dalbergia sissoo (shisham) and Anogeissus latifolia (axle wood).

Stumps and bales are made of Morus spp. (mulberry) and Grewia tiliaefolia (dhaman).

In India, tennis and badminton rackets are made of mahogany and maple wood. The racket frames are made of Prunus padus, Dalbergia sissoo, Toona ciliata, Melia azedarach, etc.

Very close-grained woods are acquired for high class turnery and carving. Walnut is much in demand in North India and Kashmir for this purpose. The sandalwood carvings of Mysore are equally well known. Sissoo and ebony are also used high class carving and inlay work in North India.

Dalbergia latifolia is commonly used in Kerala for carvings of idols, animals, birds, etc.

Wood carving is an ancient craft in which the West Bengal excels. The items include are dolls and toys, owl, horse, etc. Recently many piece goods including stands for table lamps are being manufactured. Shisham wood is used in abundance.

Erythrina spp., Gyrocarpus spp., Bauhinia malabarica are used for making toys in Karnataka. Hymenodictyon excelsum (Kuthan) is the best toy wood in U.P.

Indian combs such as those used by Sikhs in the hair are made of Buxus spp. (boxwood), Adina cordifolia (Haldu), ebony and sandal-wood.

Science Fair Project # 6. Seasoning of Wood:

Wood always contains moisture, the amount of which varies from 40 per cent to 100 per cent or more of the dry weight. The water found within the wood is known as hygroscopic water. The amount of hygroscopic water constitutes from 20 to 35 per cent of dry weight. This property of wood is known as hygroscopicity. The moisture content of wood has an important bearing on its weight, density, and often on its strength.

It is only the loss of hygroscopic water which is responsible for the increase in strength that accompanies seasoning, as the drying out of wood is called. The loss of hygroscopic water causes the shrinkage of wood. This tendency of wood to shrink as it dries is one of the great drawbacks to its use. As the result of uneven shrinkage, warping and other defects may develop, which tend to counteract any increase in strength.

However, dried or seasoned wood is for the most part stronger, harder, stiffer and more durable than unseasoned wood. Artificial methods, of wood seasoning are employed.

There are two chief types of artificial wood seasoning:

1. Air seasoning, and

2. Kiln drying.

1. Air Seasoning:

Here, the moisture is removed by exposure to air without resorting to artificial heat. It is carried out in open until the wood ceases to lose weight. The ultimate water content varies from 12 to 30 per cent. The main objects of air-seasoning are to reduce weight, the amount of shrinkage and other defects. This is a long-time process.

2. Kiln Drying:

Here, heat is applied to wood in an enclosed space. In this process, the moisture is removed more rapidly and more completely. The final moisture content varies from 4 to 12 percent. If green wood is kiln-dried, warping and other defects may be prevented. This process is completed in short duration.