Scholarly Journal of Agricultural Science Vol. 2(5), pp. 103107, May 2012 Available online at http:// www.scholarlyjournals.com/sjas ISSN 22767118 2012 ScholarlyJournals Full Length Research Paper Physical, Mechanical and Seasoning Properties of Jackfruit (Artocarpus heterophyllus) Wood in Bangladesh M. Rowson Ali 1, Md. Jahangir Alam 2, Newaz Ahmed Chowdhury 3 1,2 Bangladesh Forest Research Institute, Chittagong4000, Bangladesh and 3 Bangladesh Academy for Rural Development (BARD) Kotbari, Comilla 3503 Bangladesh. Accepted 19 May, 2012 The physical, mechanical and seasoning properties of Jackfruit (Artocarpus heterophyllus) species were studied. The timber is of light weight and specific gravity 0.46 at green condition which is less than that of Chittagong teak (Tectona grandis). The shear parallel to grain of jackfruit wood was found greater than that of teak but the specific gravity was found less than that of teak. From different test results it is revealed that the species is moderate strong. It can be seasoned with care within 6 to 7 days and suitable for making furniture, building construction, carving, musical instruments (drums, metallophone stands) and carpentry. Keywords: Physical, Mechanical, Seasoning Properties; Jackfruit, Teak INTRODUCTION Jack fruit (Artocarpus heterophyllus) is a medium sized to large evergreen, glabrous tree with short trunk and large crown (Das and Alam, 2001). It is one of the most popular and important food crops tree and recognized as the national fruit in the country (Haque, 1977). The tree attains a height of 8m 25m. The straight cylindrical stem is covered with rough bark which exudes milky latex. The wood is yellow when freshly cut but gradually turns light brown on exposure (Manjunath 1948). The timber is used for house and ship building, furniture and other purposes (Watt 1972). Due to global timber crisis it is worthwhile to search the various end uses of jackfruit wood. Durable wood is used for carving, musical instruments of drums, and met allophone stands and carpentry. The ornate wooden plank called Avani Palaka made of the wood and its grain is deeply interlocked and resists cracking. MATERIALS AND METHODS Determination of physical properties namely moisture content, specific gravity and shrinkage, each tree was divided into its butt, middle and top position. The sizes of the samples are 2.54 cm x 2.54 cm x 5.08 cm and 5.08 cm x 5.08 cm x 15.24 cm respectively. For determination of mechanical properties the bolts were marked into 6.35 cm 2 according to the standard sawing diagram and were sawn to 6.35 cm x 6.3 cm x 2.50 m sticks. The sticks were prepared in pairs. One stick was taken from each test in green condition and the other for airdry condition. The sticks for airdry tests were staked using suitable stickers inside a drying shed and allowed to attain the equilibrium moisture content of 1214%. Measurement of properties Small clear specimens were tested, in both green and airdry states, for the following physical and mechanical properties using the procedure given in ASTM (Anon, 1971). Moisture content Moisture content is the amount of water in wood expressed as a percentage of its oven dry weight. Corresponding Author Email:newaz_bard@yahoo.com
Scholarly J. Agric. Sci. 104 Table 1. Physical Properties of Jackfruit Species Seasoning condition Specific gravity based on oven dry weight Shrinkage (%) from green to oven dry condition based on green dimension Volumetric 1 2 3 4 5 6 Tectona grandis Artocarpus heterophyllus Air Dry Air Dry 0.58 0.59 0.46 0.48 0.61 0.49 4.50 2.47 5.0 5.72 Specific gravity The specific gravity was determined based on oven dry weight and volumes at green, 12 % moisture content and oven dry conditions. Shrinkage The volumetric shrinkage was determined from the data for density measurements. The volume values at green, 12 % moisture content and oven dry conditions were used for the determination of volumetric shrinkage. Mechanical properties All the test sticks were dressed to 5.08 cm x 5.08 cm x 2.50 m strips and clear specimens to the sizes specified by the American Society for Testing of Materials (ASTM) standards D 14352 (1). The specimens of various parameters were tested in accordance with the specifications of ASTM except toughness. The tests for mechanical properties were carried out in a Riehle screw power type universal testing machine. Toughness tests were performed in a toughness testing machine designed by the US Forest Products Laboratory, Madison, Wisconsin. Static bending It furnishes data on bending strength and stiffness for such uses as beams, joists, etc. Specimen of 2 x 2 x 30 cm is tested on a 28 cm span with centre loading. The parameters of static bending are as follows: a) the numerical value of бpl can be obtained in equation (eqn.1) 3 Pl бpl = (1) 2bh 2 The modulus of rupture R (eqn.2) can be found by substituting the maximum load, P 1 for the load at the proportional limit 3 P 1 l R = (2) 2bh 2 The modulus of elasticity (eqn. 3) can be determined and substitution Pl 3 E = (3) 4 ybh 3 Where, P = Load at the limit of proportionality l = Span of the test specimen b = Breadth of the test specimen h = Depth of the test specimen y = Deflection at the limit of proportionality Seasoning properties Six planks of 2.5 cm x 20 cm x 2 m dimensions were taken as sample boards. The samples along with other planks were stacked following the box pilling method in an open yard and also in a compartment type steam heated kiln. Air drying was done in the months of March and April. Kiln drying was accomplished following a standard schedule developed at the BFRI (Sattar, 1997). The initial and the final moisture contents were determined. The total drying times from green condition to 1214% moisture content were ascertained. Results and Discussions General properties and description of wood The wood is yellow to yellowish brown. It is of light weight wood with good dimensional stability and moderate mechanical strength. Physical properties The average values of physical properties such as moisture content, specific gravity and volumetric shrinkage of Jackfruit determined in green and airdry conditions are presented (table 1). It is evident from data that the specific gravity and volumetric shrinkage of
Ali et al. 105 Table 2. Comparison of Mechanical Properties of Jackfruit with Teak Properties Static bending (kg / cm 2 ): Modulus of rupture Modulus of elasticity Compression parallel to grain: (kg / cm 2 ) Maximum crushing strength (kg / cm 2 ) Species / Seasoning conditions / values Jackfruit Teak Airdry Airdry 269 481 58 125 195 382 701 64 220 305 514 867 120 288 383 628 1008 131 Compression perpendicular to grain: (kg/cm 2 ) 65 67 119 Hardness, load required to embed a 1.13 cm ball at half its dia (kg) (kg) End (kg) Shear parallel to grain: (kg) (kg) Nail withdrawal: (kg) (kg) End (kg) Cleavage load to cause splitting: (kg/cm of width) (kg/cm of width) Tension perpendicular to grain: Tensile strength radial (kg / cm 2 ) Tensile strength tangential (kg / cm 2 ) Toughness: (cm/kg specimen) (cm/kg specimen) 400 415 405 103 123 110 90 43 49 22 29 291 321 480 490 425 145 172 125 110 56 76 28 33 287 300 495 518 495 86 103 145 132 95 68 77 44 49 387 419 374 513 532 550 532 97 82 77 68 66 79 41 47 321 326 timber is 0.46 and 5.72 respectively. On the other hand, the specific gravity and volumetric shrinkage for teak is 0.58 and 5.0. Data also indicate that the volumetric shrinkage of Jackfruit is more than that of teak. Mechanical properties In respect to mechanical properties the individual strength value was computed from the data collected for nine different tests like static bending, compression parallel to grain, compression perpendicular to grain, hardness, and shear parallel to grain; nail withdrawal, cleavage and toughness. The average values of various strength properties in the both green and air dry conditions are shown in table 2. The table showed that all the parameters of mechanical properties except shear parallel to grain have the lower values in both green and air dry conditions for jackfruit wood as compared to teak. The values of shear parallel to grain in both radial and tangential have the higher for jackfruit wood as compared to teak. It is also showed that the values of nail withdrawal of jackfruit in airdry condition are higher than that of teak wood. The values of physical and mechanical properties were also compared with the physical and mechanical properties of teak to find out the suitability of Jackfruit expressed in percentage (table 3). Seasoning properties Jackfruit wood planks of 2.5 cm dimension take 6.5 days and 32 days respectively in kiln drying and air drying from the initial green condition to 1214% moisture content. Air drying was undertaken in the postwinter period which is considered to be favorable season for air drying in our country (Sattar et al. 1992). Seasoning characteristics of
Scholarly J. Agric. Sci. 106 Table 3. Physical and Mechanical Properties of Jackfruit Relative to Teak (in percentage) Properties Specific gravity based on oven dry weight and Volume at test Volume at oven dry Species / Seasoning conditions / values Jackfruit Airdry 79 81 80 Volumetric shrinkage (%) from green to oven dry condition based on green dimension: 114 Static bending: Modulus of rupture Modulus of elasticity Compression parallel to grain: Maximum crushing strength 52 61 55 70 48 49 43 59 51 59 Compression perpendicular to grain: 97 97 Hardness, load required to embed a 1.13 cm ball at half its dia. End Shear parallel to grain: Shearing stress radial Shearing stress tangential 81 90 80 89 82 80 120 149 119 150 Nail withdrawal: End Cleavage load to cause splitting: Tension perpendicular to grain: Tensile strength radial Tensile strength tangential Toughness: 76 140 87 136 95 162 63 85 64 96 50 68 59 70 75 96 77 92 Table 4. Seasoning Characteristics of Jackfruit Timber Drying method Kiln drying Air drying Drying time from green to 1214% (days) 6.5 32 Jackfruit timber is given in table 4. Conclusion and Suggestion The wood is very stable and yellowish brown, medium textured. It is light density wood with good dimensional stability and moderately mechanical strength. It possesses good turning and shaping properties and made finishing properties excellent. The wood seasoned well with best durability. In our country the tree has been planted in homestead forest for their local consumption of
Ali et al. 107 timber and wood and extensively used for general carpentry work, door, windows, furniture, cabinet making and brush backs. References Anon. (1971). ASTM Standards: Part 16, Structural Sandwich Construction: Wood and Adhesive, American Society for Testing Materials, Philadelphia, USA, pp. 64121. Das, DK, Alam, MK (2001). Trees of Bangladesh, Bangladesh Forest Research Institute, Chittagong. Haque, MA (1977). Variability in Fruit Characteristics of Selected Jackfruit (Artocarpus heterophyllus Lam.) from Some Localities of Mymensingh District, Bangladesh, J. Agric. Sci., 4(1):119120. Manjunath, BL (1948). The Wealth of India, Raw materials, Vol. 1. New Delhi, India, pp.125126. Sattar, MA, Aktaruzzaman, AFM (1997). Properties and Uses of Jackfruit, (Artocarpus heterophyllus) Wood, Bulletin 2, Forest Products Branch, Bangladesh Forest Research Institute, Chittagong. Watt, G (1972). A Dictionary of the Economic Products of India, Vol. 1, Periodical experts, Delhi, India, pp. 330332. 5