Wong Ting Chung & Ling Wang Choon Installed Processing Capacities of Sarawak's Timber Mills in the Context of Raw Material Availability
The installed processing capacities of timber mills in Sarawak are quantified by administrative as well as production regions. These capacities are discussed in the context of existing raw material availability and its effects on the viability and mode of mill operation. Although Sarawak still enjoys an abundance of timber as a resource, the production volume or availability of raw material is not evenly distributed throughout the state. The implications of the raw material supply situation on the present and future development of the timber industry are also looked at.
Celina Yong Foreign Labour in the Sarawak Timber Industry
The timber industry in Sarawak contributes RM2.9 billion out of total exports of RM9.6 billion from January to June 1999. Statistics show that the sector relies heavily on foreign labour. Since the need for this foreign labour is increasing yearly, it should be taken into consideration in planning on human resource needs in the State. The purpose of this study is to provide data for planning on future foreign manpower needs.
In July 1999, the Sarawak Timber Association (STA) collected data from three sources, namely from the
- Plywood and Veneer, Sawmilling, Moulding, Furniture and other Woodworking categories,
- Medium Density Fibreboard (MDF) and Particleboard categories and
- Forest Plantation category. Three different questionnaires were sent to 168 member companies from the said categories. Of this, a total of 73 member companies responded. The companies that did not respond were not significant employers of foreign labour.
This study yielded several interesting results. Firstly, there was strong reliance on foreign labour, amounting to 70% of total workers in the State. Secondly, the forest plantation category would require approximately 10,000 additional workers in the initial stage of implementation. Most of this labour would probably come from outside Malaysia, since, demographic studies have shown that it would be quite unlikely for the State to meet this demand of 10,000 workers.
It was also interesting to note that there was no statistical significance in cost to employers between hiring either locals (i.e., Sarawakians) or foreign workers. Nonetheless, the data compiled in this study have shown that the employers have a preference for foreign workers. Foreign workers were viewed as a more reliable and consistent source of labour, with abundance in supply. This would enable the member companies to plan and attain their production targets. Further research would be required to gauge the thinking of local workers with respect to the timber industry.
Len Talif Salleh & Nicholas Andrew Lissem Management and Utilization of Milling Residues in Sarawak
This paper reviews the overall and current status of management and utilization of timber milling residues in Sarawak based on field studies and observation conducted over the years.
The rapid development of the timber downstream processing sector during the 1990's has inevitably led to the generation of enormous quantities of milling residues in the forms of peeler cores, off-cuts, slabs, shavings, sawdust, log-ends and other kinds of rejects. Previously, the presence of these residues in large quantities posed disposal problems and oftentimes was handled inefficiently without much economic attention. Inefficient and indiscriminate disposal practices like uncontrolled incineration, dumping and open-air burning led to environmental pollution and other problems.
Like other industrial activities, the wood-based downstream sector faces stringent environmental regulations governing emissions from mills and conditions in the working environment. The maturing awareness of the general public on environmental issues has created concern amongst the wood processors to continuously seek ways to improve their overall residue management practices. Concerted efforts have also been made to improve recovery and to increase the utilization of milling residues.
The management of milling residues in the sector has improved significantly. Most mills have installed or put into place, systems and personnels for collection, storage and disposal of wastes. It is also encouraging that a number of mills have been set up to convert milling residues into valuable products like fiberboard, particleboard, wood cement board, charcoal briquett and energy in recent years. Total investment on these facilities throughout Sarawak has reached about RM750 million. The total export value of timber products manufactured from milling residues in 1998 was RM120 million. This value is expected to rise in years to come with increasing production capacity and overseas market demand. This positive outlook would encourage intensified and diversified utilization of milling residues and hopefully would steer the state towards the achievement of "zero waste" in the timber industry.
Emily Wong, Jonus Ko & Jordy Ko The Issue of Wood Residues in Kuching Region
The timber industry in Sarawak has experienced phenomenal growth over the last few years. From 1990 to 1998, the volume of sawn timber exported had increased twofold while that of plywood registered a twelvefold increase. The amount of wood residues produced was deemed to have increased proportionally. Traditionally, disposal of wood residues was mostly done by either open burning or dumping in landfills, both of which are no longer acceptable.
A 6-week study was carried out in early 1999 to look at the true extent of problems faced in the disposal of wood residues by mills of STA Members in the Kuching District. Focus was placed on the volume of residues, such as off-cuts and sawdust generated by the mills. Collection of hard and soft data was done through questionnaires, interviews, mill visits and where necessary telephone conversations.
It was found that a large number of mills were unable to participate in this study as many of them had ceased operations because of shortage of logs and flitches for production. This had, in fact, caused a shortage of waste/residual material for burning to run kilns and co-generation plants. As such, there was no problem in the disposal of wood residues in Kuching.
Various methods had been employed by the mills surveyed to reduce their wood residues. One of these methods was to sell residues such as slabs and off-cuts to wood chipping companies, or businesses that require wood as a fuel source for boiler and power production. Burning, however, seemed to be the favourite method for disposing wood residues.
Ting King Boh Some Common Problems Encountered in Finger Jointing of Sarawak Timbers
Finger jointing is increasingly employed in timber mills in Sarawak for the purpose of improving recovery as well as widening the range of products. Some of the problems commonly faced by novice operators are described together with recommendations for rectification.
Puad Elham & Koh Mok Poh Wood Briquetting - Method of Utilising Sawdust in Malaysia
Wood-based industries produce huge quantities of residues that were inefficiently used causing extensive pollution to the environment. In the manufacture of wood products, large quantities of wastes such as sawdust, wood shavings, bark, chips, edgings and off cuts of defective timber are produced and available in huge quantities. Apart from the problems of transportation, storage and handling, the direct burning of loose biomass in conventional grates is associated with very low thermal efficiency and widespread air pollution. Today, because of the drastic increase in the production cost and the declining in the supply of timber, wood briquetting offers a neat and economical utilisation of sawdust in Malaysia.
Nigel P. T. Lim, Siti Hanim Sahari & Pek Yaw Kee Bond Performance of Plywood Manufactured from Small Diameter Acacia mangium
3-ply and 5-ply plywood test panels were produced from 15-year-old Acacia mangium with mean oven-dried density of 0.56 g/cm3. The test panels were fabricated using veneers of 1.3mm and 2.4mm thickness and three types of adhesives, namely urea formaldehyde, melamine urea formaldehyde and phenol formaldehyde as binders. Test specimens were subjected to different treatment conditions and subsequently tested for tensile shear strength. It was found that the tensile shear strength of almost all the test specimens exceeded the prescribed minimum strength requirement of 0.7 Nmm-2 stipulated in the Japanese Agricultural Standards. It has been inferred that small diameter Acacia mangium is a suitable raw material for making plywood.
Siti Hanim Hj. Sahari, Nigel P. T. Lim & Karin Kerman Variations of Melamine and Urea Content in Melamine Urea Formaldehyde Adhesives and its Effect on Some Properties of Plywood
Melamine urea formaldehyde (MUF) adhesive with low emission of formaldehyde can be formulated by lowering the molar ratio of formaldehyde to urea and melamine during synthesis. In this study, the molar ratios of formaldehyde to urea and melamine are decreased from the conventional value of 2.25 to two respective values of 1.5 and 1.125.
The two different compositions of MUF resins were prepared in the laboratory by secondary addition of 0.5 mole and 1.0 mole of urea and melamine respectively whilst the formaldehyde content remained the same. 1.3mm-thick veneers of RED MERANTI (Shorea spp.) and YELLOW MERANTI (Shorea spp.) were used with these formulations to fabricate 30cm by 30cm 3-ply test panels of plywood. Test specimens from these panels were subjected to two forms of treatment, namely, hot and cold water soaking test and cyclic boiling test prior to determining their tensile shear strength for their relative compliance to Type 1.5 of the Japanese Agricultural Standards (JAS). Formaldehyde emission tests were also conducted using the dessicator method and quantitatively determined by colorimetry. The results were also compared to that of a commercial preparation of MUF.
It was found that the test specimens with MUF 1.125 formulation had better tensile shear strength and lower emission of formaldehyde. It was also found that the tensile shear values of test specimens from YELLOW MERANTI were higher by 20-25% than that of RED MERANTI.
Dr. Mohd. Nor Mohd. Yusoff Properties of MDF from 2-year-old Acacia mangium
Currently, Malaysia has a total of ten MDF mills with a production capacity of approximately 1.15 million m3 per year. Rubberwood has been the raw material for the mills in Peninsular Malaysia. Recently, one mill with a capacity of 15,000 m3 per year has begun to use oil palm empty fruit bunches as its raw material. For the two mills in Sarawak, the raw materials are in the form of wood residues from sawmills and plywood mills. In view of the impending dwindling supply of rubberwood and the associated problems of mixed hardwoods, alternative raw materials need to be explored.
In this study, 2-year-old Acacia mangium wood was obtained from a plantation in Kemasul Forest, Mentakab, Pahang. The wood samples were divided into two lots i.e. one with bark and the other without bark. Wood chips of dimensions 2.0 x 2.5 x 0.2 cm were produced using a pilot plant Taihei Disc Chipper. Wood chips containing the bark and without bark was steamed separately in a digester at a pressure of 5.63 kg/cm2 for 5 minute and subsequently defibrated in the Sprout-Bauer refiner using a refining clearance of 0.33mm. The design of the refining plate used was D2A505 type. The fibres obtained were air-dried overnight and then dried in the oven at 60�C for 24 hours to obtain a moisture content of 3 - 4 %. For board making, urea formaldehyde resin and wax emulsion were used to mix with the dry fibres in the rectangular MDF blender. Board forming was carried out by spreading the resinated fibres manually into a wooden mold of dimensions 32 x 32 x 25 cm. The fibre mat was cold pressed at a pressure of 10 kg/cm2 for 1 minute. The consolidated mat was hot pressed between two stainless steel caul plates in a Taihei Oil heated Hydraulic Press at a temperature of 190�C for 4 minutes. The MDF boards of 12mm thickness were produced at a density of 600 and 700 kg/m3 and resin content of 9 and 11%. Thus, a total of 24 boards were produced at different conditions. The boards were then conditioned for 24 hours at temperature of 23�C and relative humidity of 55%. The boards were evaluated for their mechanical and dimensional properties. The average wood density of the samples determined was 490 kg/m3. It was observed that MDF boards made from samples without bark gave a slightly darker colour compared with commercial rubberwood MDF. Boards containing bark gave darker colour than those without bark. Interestingly, the presence of bark in the samples did not seem to affect the thickness swelling and water absorption of the boards. However the MOR and IB were lower in boards made from samples with bark compared with boards without bark. The MDF boards made at a density of about 700 kg/m3 could satisfy the requirements of the European Standard for general purpose boards for use in dry conditions in terms of MOR, MOE and thickness swelling with the exception of IB which was below 0.6 MPa.
Pek Yaw Kee, Nigel P. T. Lim & Peter C. S. Kho Milled Hampas as an Alternative Filler for Plywood Adhesive
Plywood manufacturing, the backbone of the timber processing industry in Sarawak, consumes an estimated 40,000 metric tons of wheat flour as filler in the plywood adhesive. It is therefore deemed worthwhile to explore the possibility of using hampas, a fibrous waste residue generated by the sago starch processing industry in the state, as alternative filler.
Viscosity studies were carried out for three different replacement levels of wheat flour. It was found that hampas could not be used to wholly replace the wheat flour, but partial replacements might be feasible. A typical plywood adhesive of urea formaldehyde enriched with melamine urea formaldehyde was chosen and two formulations comprising 50% and 75% replacement levels were formulated. Plywood test panels were fabricated using veneers of RED and YELLOW MERANTI (Shorea spp.). The tensile shear strength readings of test specimens were found to meet the minimum strength requirements of the Japanese Agricultural Standards. The preliminary findings indicate that it is possible to use hampas as a partial replacement for wheat flour in plywood adhesive.
Mohd. Hamami Sahri, Mohd. Shahwahid Hj. Othman & Wong Ee Ding Green Veneer Recovery Study from Selected Plywood Mills in Pahang
Plywood mills recovery studies were conducted in the state of Pahang Malaysia. The primary objectives were to evaluate the efficiency and to quantity mill residues generated. Recovery study of plywood mills was carried out in 8 involving 62 logs from 4 districts (Bentong, Jerantut, Kuantan and Temerloh). A survey of the present status of plywood mill residue utilization was included in this study.
In the veneer and plywood industry, the sampled mills gave a recovery of above 60% of green veneer. The study revealed that Mill C yielded the highest recovery rate of green veneer with 83.37%, followed by Mill A with 79.69%, Mill F with 74.34%, Mill H, 74.36%, Mill D, 69.49%, Mill E, 67.17%, Mill B, 66.36% and the lowest was Mill G with 64.44%. Veneer round-up and peeler cores are two major contributors to the pool of wood residues or wastes.
For diameter classes, diameter range 40 - 49.9 cm had the highest with 80.28% and diameter range 30 - 39.9 cm had the lowest with 66.86%. For wood classes, mixed hardwood (unknown species) had the highest with 79.82% and light hardwood had the lowest with 68.19%. Although a good percentage of these residues are currently being converted into other products or used as solid fuel by the operators concerned, the majority however, could still be reprocessed into higher value-added products such as, briquettes, and composite board products.
Dr. Rahim Sudin, Dr. Mohd Nor Mohd Yusoff, Suffian Misran, Saimin Basir, Jalali Salleh & Ahmad Sharafi Othman Properties of Oriented Strand Board Manufacture form Acacia mangium
Oriented Strand Board (OSB) is a new type of wood composite, which is yet to be commercially produced in Malaysia or South East Asia region. It is made from long, thin and narrow wood strands bonded by a synthetic resin and converted into a solid panel during the hot pressing operation. In this study, the wood strands of dimensions 60 - 150 mm in length, 35 mm width and 0.5 - 0.8 mm thickness are oriented parallel to each other in each layer. Standard OSB normally consists of three layers in which each layer is perpendicular between one to another. In some cases, the OSB also can be produced in five or seven layers depending on type of application. Unlike plywood, OSB normally manufactured using small diameter logs regardless of any wood species. This type of board is considered as an engineered product with a great strength and dimensionally stables. This paper discusses the feasibility of using 10-year-old Acacia mangium obtained from thinning operation of Batu Arang Forest Plantation in Rawang. The study showed that the OSB made at density about 650 kg/m3 comply with the minimum specification of base particleboard as specified by the Japanese Industrial Standard (JIS A 5908: 1994). The resin content used was in the range of 3, 5 and 7% based on oven-dried weight of wood strands. Based on the physical and mechanical strength of OSB, it is expected that this new type of wood based panel product may have a good potential to supplement the current shortage of plywood application in the near future.
Peter C. S. Kho, Edward P. L. Foo & Kho Gek Hoi Dimensional Stability of Some Sarawak Timber Species
The dimensional stability of some species of Sarawak timber was investigated. Sixty samples of each species were placed in a humidity chamber that was set at 35�C and at pre-determined humidity levels covering both desorption and absorption processes.
The dimensional changes of the species are discussed in this paper. These results will assist all timber users in estimating rough sawn timber sizes for manufacturing joinery and furniture products.
Rokiah Hashim, O. Sulaiman, M. H. Simatupang & A. Z. Mohamed Mechanisms Causing Discoloration of Rubberwood - Effect of Aerobic and Anaerobic Condition Towards the Brownish Discoloration of Rubberwood using Fresh Pressed Liquid
The study investigated the mechanism causing brownish discoloration in rubberwood by exposing fresh pressed liquid to aerobic and anaerobic test conditions. The results showed that discoloration was prominent in the aerobic condition. It was more prominent in the phenolic fraction. There was an increase in pH of wood that had undergone discoloration.
Edward P. L. Foo, Tan Jui Liah, & Mohd. Salleh Solar Drying of Selected SarawakTimbers
The 2-tonne solar kiln at Timber Research and Technical Training Centre (TRTTC) is discussed. The system has some advantages over conventional drying kiln in that it is cheaper to build, simple to operate, easy to maintain and more environment friendly.
Results of the fifty-eight species dried in this kiln are presented in this paper.
Kandau Jenang, Dr. Makoto Kiguchi & Jiro Kawamura Finishing Properties of Acacia mangium Grown in Sarawak Compared to Nyatoh rian and Ramin
The ever increasing demand for the supply and choice of affordable raw materials by the furniture and joinery industries makes it necessary to assess the finishing properties of all potential species including a locally grown Acacia mangium to ascertain their suitability. Finishing properties of Acacia mangium grown in Sarawak were assessed based on dimensional stability, contact angle, extractives content, colour and gloss change, adhesion and hardness tests of polyurethane and NC lacquer-coated samples. Comparison of these properties with Nyatoh rian (Palaquium gutta) and Ramin (Gonystylus spp.) indicated that the finishing properties of Acacia mangium have many similarities to Nyatoh rian but slightly less similar to Ramin.
Hong Lay Thong Accelerated Technique for Estimating Natural Durability of Timbers
Durability or the life span of a timber when exposed to the environment in normal use is an important criterion when selecting timbers for specific end-uses. Traditionally the natural durability of timbers is obtained by subjecting the timbers to a time-consuming test commonly called "graveyard" exposure test. This involves inserting timbers into the ground and recording their degradation over a period of time (years). This procedure exposes the timber to bio-deterioration by some of the more important groups of destructive organisms; insects, termites and decaying fungi. Data obtained (over the last 40 - 50 years) through such "graveyard" exposure tests are used in the natural durability classification of Malaysian timbers.
In order to derive a quick procedure for estimating the natural durability of timbers the accelerated laboratory procedure (modified ASTM D2017 soil block method) for testing the resistance of seventeen timbers to fungal decay was evaluated.
It has been shown that a good estimate of the natural durability of the timbers could be obtained using this accelerated laboratory procedure which takes 12 weeks by taking into account some of the physical and chemical characteristics of the 17 timbers.
The physical and chemical characteristics evaluated that have good correlation for estimating durability are density, water absorption capacity, hot water extractives and pH. A formula (regression equation) has been obtained using these four factors to predict durability. The formula obtained is y=11.028 - 31.659(X1) + 0.007(X2) - 0.447(X3) + 0.852(X4), where y = estimated durability, X1 = density, X2 = water absorption capacity, X3 = hot water extractives, X4 = pH.
The natural durability classification obtained using the formula and those obtained by the conventional graveyard test are comparable. Therefore, the formula could be used as a quick means to estimate the natural durability of a timber in which data from field exposure trials are unavailable.
Koichi Yamamoto Decay Resistance of Plantation Teak Wood
Teak wood from the outer sapwood to the pith was subjected to a laboratory decay test according to JIS Z2101. Laboratory decay rating against Fomitopsis palustris and Trametes versicolor is durable in the outer heartwood, and is less durable in sapwood and the inner heartwood. The less durable property of the inner heartwood compared with the outer heartwood would be attributable to not only the amount of extractives but also juvenile wood judging from the wood density.
Nebil Bourguiba LOSP Timber Treatment in Malaysia: Quality and Environment
The main types of wood preservatives used in Malaysia are creosote, CCA, borons compounds, anti-sapstains and Light Organic Solvent Preservatives (LOSP). These preservatives have different uses. Boron compounds associated with anti-sapstains are mainly used for treating rubberwood components for furniture whereas CCA is best for treating rough sawn timber in ground contact or in water. Creosote can be used on poles, sleepers and other timber in ground contact. For quality and environmental reasons, LOSP should be preferred inside and outside the house, for above the ground contact situations like windows, doors, frames, roof trusses and moulding components.
LOSP is applied to timber by a double-vacuum process that can be described as containing 6 major stages: initial vacuum, flooding, pressure period, initial drain, final vacuum and final drain. This is done in modern treatment plants that comply with the British Wood Preserving and Damp Proofing Association's code of practice for safe design and operation for timber treatment installations.
In any case, all wood preservatives are safe when used as directed and treated timber is still the most environmentally friendly building material to use.
Trusting this as required, this paper will be general and of no commercial nature. It will still give LOSP treatment the importance they should have in Malaysia the one they already have in other parts of the world like Europe, Australia and New Zealand.
Clarence Tan Protecting Wood from Biological Stain
Sodium pentachlorophenate (NaPCP) was once widely used as an active for controlling stain fungi, usually in combination with boron salts to augment performance and reduce cost. This use has declined rapidly due to increasing health, safety, and environmental concerns about the chemical.
Although there was a huge effort to develop replacement systems, which worked and were cost effective, this was a very difficult time for the industry. However, producers in Southeast Asia are in a position to minimise the impact of these bans, in that there are already alternative products available to take the place of NaPCP.
From the foresters and millers perspective, there are three major groups of fungi that cause concern - sapstain fungi, mould fungi and decay fungi. Sapstain and mould fungi do not weaken or physically damage timber. They cause discolouration, which in turn reduces the commercial uses and value of the timber and log products.
Anti-sapstain formulations are part of the solution to sapstain and mould fungi problems, which in the paper describes "Protecting Wood from Biological Stain".
Ling Wang Choon, Lai Jiew Kok, John Sammy & Peter C. S. Kho Evaluation of Anti-Sapstains Formulations for the Protection of Sawn Ramin and Bindang in Sarawak
A series of studies were conducted to find suitable commercially available formulations that may be able to replace Sodium Pentachlorophenate (NaPCP) for treating sap-stains in Sarawak.
In the first and second studies, seven formulations, prepared according to manufacturer's specifications, were used to dip-treat freshly sawn Ramin (Gonstylus bancanus) and Ramin that had been stored under water for 6 months. 20 rough sawn samples of dimensions 25mm by 150mm by 1500mm were used for each treatment. Two visual assessments for extent of growth of mould and sap-stain infection on the treated boards were conducted on the 4th and 10th week. After the visual assessment on the 10th week, the boards were surface-planed before a final assessment on the extent of sap-stain infection was done. These two tests were conducted in the wet season.
A third study was carried out in the dry season in a sawmill in Lawas using 10 formulations mixed with an insecticide. Freshly sawn Bindang (Agathis borneensis) boards of dimension 25mm by 150mm by 2300mm were hand dipped in solutions prepared from river water. Visual rating for mould, stains and insect attack was carried out on the 4th and 10th week.
From the three studies, it was concluded that Ramin stored under water for 6 months and tested in the wet season was the most difficult to protect, followed by fresh Ramin and Bindang boards. Only three formulations performed as well as NaPCP in the first study while all 10 formulations were found to perform well at the 4th week assessment in the Lawas study.
Alik Duju Strength Properties of Acacia mangium Grown in Sarawak
Ten trees of 13-year-old Acacia mangium were obtained and a total of fifty-four small clear specimens were tested. The British Standard on method of testing small clear specimens of timber was adopted to test the strength properties of the species. It was found that the mean values of modulus of rupture, modulus of elasticity and compressive strength tested at green condition were 86.4 MPa, 10900 MPa and 36.8 MPa respectively. The average moisture content was 114% and their basic density was 0.51 g/cm3. In term of timber grouping, it was classified under light hardwood and strength group C. It was revealed that the strength values and basic density were higher at the outer portion compared with the inner portion of the wood.
Salamah bt. Selamat & Shaharuddin b. Hashim The Effect of Wood Density on Copper- Chrome- Arsenic (CCA) Preservative Retention in Selected Malaysian Hardwoods after Full-Cell Treatment
The hardwood timbers in this country are classified into three classes based on the density and natural durability. The classification is heavy hardwood, medium hardwood and light hardwood. Heavy hardwoods are timbers that are heavy and posse density above 880 kg/m3 at 15% moisture content, very strong and are naturally durable. Medium hardwoods are timbers that are moderately heavy to heavy and range in density from about 720-880 kg/m3 at 15% moisture content. They are moderately durable but insufficient for use in exposed conditions and in ground contact unless they are properly treated with wood preservative. The objective of this study is to monitor the effect of density variation on CCA preservative retention of 8 selected timbers in the group of medium hardwood known as KEMPAS (Koompassia malaccensis), MERBATU (Maranthes spp.), NYALIN (Xanthophyllum spp.), MEMPENING (Lithocarpus spp.), PERAH (Elateriospermum tapos), RENGAS (Gluta spp.), KASAI (Pometia spp.) and KELAT (Eugenia spp.). About 50 pieces of CCA treated sample from each timber type at the sample thickness 50 to 75 mm are selected randomly from the CCA commercial treatment plant. All samples are treated using full-cell process according to MS360:1986 with the solution strength is about 6% w/w. Wood samples are prepared and analysed for CCA content according to the standard method MS821:1994. The test result is presented for each timber type in the form of percentage of copper sulphate, sodium dichromate and arsenic pentaoxide. The relation between density of each timber and the dry salt retention is also performed.
Wan Ali bin Wan Ibrahim Systematic Studies of Shorea albida Sym.
This systematic study of Shorea albida Sym. has uncovered the differences between Alan batu and Alan bunga that share the same botanical identity. The study involved was the anatomical, morpohological and flavonoid properties. The percentage of multiseriate ray cells of Alan batu was higher than that of Alan bunga whereas the percentage of biseriate ray cells of Alan bunga was higher than that of Alan batu. The trichome that was found in Alan bunga was clear from deposit-liked structure while in Alan batu there was a deposit-liked structure in the center of the trichome. The vessel-wall pits of Alan batu were oval-shaped and quite uniform while in Alan bunga the vessel-wall pits were irregular.
Andrew Tukau Salang, Wan Ali bin Wan Ibrahim & Charles Diyom Preliminary Results on the Identification of Some Softwoods Found in Sarawak
Three genera of softwoods are commercially found in Sarawak. The most common are Agathis and Dacrydium, and Podocarpus is less common. The genus Agathis being most abundant is also popular and highly demanded for interior decoration. Because of some similarity in their appearance, they are always confusing despite the differences in prices. Wood samples from the three genera were examined to establish the identification characteristics. Initial findings showed that both the tracheid pits and the shape of cross-field pits were effective identification keys. In Agathis spp., the tracheid pits were found to be either biseriate or triseriate while in Dacrydium spp. and Podocarpus spp. were both uniseriate. However, the shape of cross-field pits in Dacrydium spp. was cupressoid and that of Agathis and Podocarpus was taxodioid.
Young Kam Han Extending the Service Life of Timber Through Fire Retardants
The development of fire retardant from first generation products that are made up of ammonium sulphates or ammonium phosphate to the current new breed of fire retardant is highlighted. This paper discusses the characteristics that are the main concerns in a fire retardant, which includes the effectiveness, hygroscopicity, corrosiveness to metal and heat degradation. Included in this paper are tests done locally and globally for a leading fire retardant in USA on corrosion, smoke emission, flame spread and fire propagation