Variability in the mechanical properties of commercially available thermally modified hardwood lumber

Research indicates that users of thermally modified wood lack information regarding the improved performance and any variations that may exist for the “same” product when manufactured by different companies. The goal of this study was to evaluate the variability in mechanical properties of three thermally modified hardwoods and determine the variability between three different manufacturers. To determine the hardness, bending (modulus of elasticity and module of rupture) and shrinkage values, testing was conducted following ASTM standard D143. The samples were conditioned at 20 °C and a relative humidity of 65% until they reached an equilibrium moisture content before testing. Analysis of variance was used to determine the variability within and between the different processes used by each company. Seven out of 18 (39%) tests indicated that there were statistical differences regarding the mechanical performances of the wood samples. Yellow poplar had the least variation between companies (only difference in equilibrium moisture content, EMC) and red maple had the most (hardness, tangential shrinkage, and EMC). While the means for these properties were statistically different, the differences in application for hardness and EMC are slight. For example, the largest difference between processes in hardness was 83.6 kg, for tangential shrinkage, 0.45% and 1.37% for EMC. These differences are suggested to be inconsequential when compared to the values that exist between different species of untreated wood.

ANATOMICAL AND PHYSICAL CHARACTERISTICS OF Cephalostachyum mannii (Gamble) STAPLETON – AN ENDEMIC SCRAMBLING BAMBOO OF NORTHEAST INDIA

Cephalostachyum mannii is a tall, graceful scandent bamboo with solid culms. It is distributed in Arunachal Pradesh, Meghalaya, Mizoram, and Nagaland states of Northeast India. The present study was carried out to investigate radial and vertical variations in anatomical and physical properties in the culms of this bamboo species. The mature culms (3-4 years old) were selected from forests of Amkassar Amlarem village, West Jaintia Hills District, Meghalaya, India. The selected internodes of culms were radially divided into outer, middle and inner zones, and vertically bottom, middle and top positions. The vascular bundles were of Type II and well developed in middle zones of both bottom and middle positions. The number and size of vascular bundles increased from inner to outer zone and decreased from bottom to top. Vessel length and vessel diameter decreased both radially and vertically. Among fibre characteristics, fibre wall thickness increased, while fibre length, fibre diameter, and fibre lumen diameter decreased significantly in both radial and vertical directions. Among physical properties, density increased, and moisture content decreased in both radial and vertical directions. Radial shrinkage was higher than tangential shrinkage. Both radial and tangential shrinkage decreased significantly from bottom to top. The fibres were long, thick-walled and highly rigid, and the derived indices do not satisfy the requirement as a superior fibrous raw material for pulp and paper making. However, this bamboo species has the potential for making good quality handicrafts and basketry.

Variation in wood physical properties and effects of climate for different geographic sources of Chinese fir in subtropical area of China

Chinese fir is one of the most important commercial timber species in China, with many geographic sources. However, little is known of the variation in wood physical properties among them. To explore the differences in wood physical properties and their influencing factors, five geographic sources of Chinese fir were selected. The variance inflation factor, stepwise regression, and principle component analysis were used to reduce multicollinearity and dimensions of the 19 wood physical properties (including density, shrinkage, and mechanical properties). The results showed that the wood density differed significantly among five geographic sources. The tangential shrinkage rate and radial shrinkage rate reached maximum values in black-heart Chinese fir (HNYX-T) but accompanied by the lowest value for difference dry shrinkage. The wood density and mechanical properties of HNYX-T was exceeded to that of others geographic sources. Fast-growth Chinese fir (FJYK-P) had the lowest value for all mechanical properties. The precipitation and temperature had significant correlations with the wood physical properties of this five geographic sources. The temperature in summer was mainly positive correlated with physical properties, while precipitation was negatively correlated with them. HNYX-T had the highest comprehensive score of PCA, followed by JXCS-R, emerged as higher-quality geographic source, which is important for selecting and utilizing geographic sources in forest management.

The Effect of Traditional Fumigation on Physical, Mechanical and Anatomical Properties of Wooden Handicraft in West Kalimantan

West Kalimantan wooden craft is internationally well known and its export is increasing. Currently, high durability and attractive color of wood material such as belian (Eusideroxylon zwageri Teysm & Binnend) is rarely available, then alternatively mangium (Acacia mangium Willd.) and laban wood (Vitex pubescens Vahl.) are used for handicraft. Fumigation is one possible way to improve wood service life and color shades. This paper determines the impact of traditional fumigation on wood raw material on physical, mechanical and anatomical properties. The timber fumigation technique was conducted for one week, with curing time from early morning until late afternoon. After treatment, the physical, mechanical and anatomical properties of wood were evaluated. The different of color before and after treatment was measured by image processing scanner Canon P 145. Physical and mechanical properties refer to the British standard method. Result shows that fumigation improves the quality of wood, especially on color of wood. The wood became dark and more shining. It’s good for the handicraft materials. The quality of wood on moisture content value, both on mangium and laban wood was increased with average 30-50%. The average value of wood density of mangium wood after treatment with fumigation was 0.52, meanwhile laban wood was 0.55. The average value of radial shrinkage of mangium wood after fumigation treatment was 3.96% and tangential shrinkage was 6.34%. The average value of radial shrinkage of laban wood after fumigation was 6.43% and tangential shrinkage was 6.08%. The average value of hardness of mangium wood after fumigation treatment was 470.13 kg/cm2 and laban wood was 625.46 kg/cm2. The Fumigated wood color was darker and more attractive for decorative and craft products than non-fumigated wood. In general, this method could be used to preserve wood and to increase the physical performance of wood as raw material for handicraft.

Suitability of Parkinsonia aculeata (L.) Wood Grown as an Architectural Landscape Tree in North Darfur State for Interior Design and Furniture

Wood samples of Parkinsonia aculeata (L.) were collected from Al bohaira Gardens of Al Fashir Town (the capital of North Darfur State, Western Sudan) where they were planted as architectural landscape trees and studied to determine their physical and mechanical properties as potential wood species for structural and furniture purposes. Moisture content, wood density (basic and oven-dry), as well as radial and tangential shrinkage were determined. The mechanical properties studied included static bending strength, compression strength parallel to the grain, the modulus of elasticity (MOE), the modulus of rupture (MOR), and the maximum crushing strength. The obtained results were compared with those of the well-known dominant small hardwood tree in the same area (Boscia senegalensis ). The wood of P. aculeata has shown medium oven-dry density (534.0 kg m-3) with reasonable bark-to-wood and shrinkage ratio. Due to the acceptable bending and compression strength results, P. aculeata wood can be considered as a suitable wood for interior design and decoration work as well as its suitability for indoor furniture.

KELAS KUAT KAYU TUMIH (Combretocarpus rotundatus (Miq.) Danser) BERDASARKAN BAGIAN BATANG (The the physical and mechanical Properties of Tumih Wood Based on Section Stem)

Tumih wood (Combretocarpus rotundatus (Miq.) Danser) is classified as an unknowntype of wood which is widely grown in peat swamp forests in Central Kalimantan. Thisstudy aims to analyze the physical properties and mechanical properties of wood in axialand radial directions so that they can be utilized properly. The results of the studyresulted in fresh water content and dry air content of wood air, each of which was71,58% and 19,33%, kiln dry weight 0,72, tangential shrinkage 9,68%, radial shrinkage5,02% and longitudinal shrinkage 0,19%. Testing of mechanical properties resulted in aflexural firmness of 618,33 kg/cm2, compressive strength parallel to the fiber 333,27kg/cm2, shear constancy 92,02 kg/cm2, hardness 355,60 kg/cm2, and stiffness at 19,50kg/cm2. Based on the Indonesian Wood Construction Regulations Standard (PKKI) NI 5-1961 tumih wood is included as a strong class III of Indonesian wood, so it is quite wellused for home building raw materials, beams, floor and wall boards, door/windowframes, and furniture.Keywords: tumih wood, physical properties, and mechanical properties.

Efektifitas Pengawetan Batang Kelapa Sawit (Elaeis guinensis Jacq.) Terhadap Serangan Rayap Tanah (Coptotermes curvignathus Holmgren) Menggunakan Campuran Boraks dan Asam Borat

Oil palm trunk has a high moisture content about 60%-300% depended on the height and age of the tree and it was presumed to have low quality and prone to decay by organisms. It is necessary to improve the trunk quality using preservatives. The purpose of this study is to calculate the value of the penetration and retention, to test the durability of oil palm trunk from the attack of termites after treated with a mixed preservative of borax and boric acid. This study used the free of defects trunk obtained from PT. Buana Karya Bhakti in Tanah Bumbu, South Kalimantan, planted in 1998 (±18 years old). The research used two factors: A (the preservative concentration variations) = a1 (5%); a2 (10%); a3 (15%); and B (soaking time variation) = b1 (1 day); b2 (3 days); b3 (5 days). The results showed that the trunk water content was 14.62%, the density was 0.25 g/cm3, the radial shrinkage was 1.48% and the tangential shrinkage was 2.17%. The average of boron penetration was 50 mm. The highest retention was got from the treatment of boron concentration 15% in 2 days for 54.71 kg/m3, while the lowest retention was from 5% boron in 1-day treatment for 13.7 kg/m3. The weight loss ranged from 19.30%-41.32%, and the average of termites attack degree ranged between 40% and 70% (categorized as moderate), while the control was decayed completely by termites in both experiments. The mortality rate in all treatments was 100%, while the control ranged from 7%-10.5%.Keywords: oil palm trunk, preservation, boron, termites

Early genetic evaluation of morphology and some wood properties of Tectona grandis L. clones

An early genetic evaluation of morphology and wood properties of Tectona grandis L. (teak) used two 4-yr-old trials with 36 clones x 3 blocks x 1 ramet (216 trees). Morphologic traits (breast height (DBH), heartwood (HWP), tree height) and some easily measured wood properties (specify gravity, tangential, radial and volumetric shrinkage; growth strain, and dynamic elastic modulus measured in standing tree, in logs, in green lumber and in dried lumber) were evaluated to establish clonal variations and their heritabilities. The broadsense heritability (Ĥ2 is greater than 0.3 for DBH, radial and volume shrinkage, growth strain and dynamic elastic modulus of standing trees and logs. DBH and tree height were not genetically correlated with any wood properties, although DBH was genetically correlated with tree height and the dynamic elastic modulus in dried-lumber. According with above results, the evaluation of heritability and genetic control of wood properties is limited when it is evaluated in the juvenile stage of T. grandis clones. However morphology (DBH and tree height), and two wood properties (radial and tangential shrinkage) and the dynamic elastic modulus of dried-lumber present opportunities in the heritability or genetic control values in juvenile and they can be introduced in the genetic program.

PROPRIEDADES FÍSICAS DO BAMBU-MOSSÔ (Phyllostachys pubescens Mazel ex H. de Lehaie) EM DIFERENTES IDADES E POSIÇÕES DO COLMO

As buscas por materiais renováveis de baixo impacto ambiental apontam o bambu como um material que promove o desenvolvimento sustentável devido ao seu rápido crescimento e por não precisar ser replantado após seu corte. O principal objetivo deste estudo foi determinar as seguintes propriedades físicas do bambu-mossô (Phyllostachys pubescens Mazel ex H. de Lehaie): teor de umidade, densidade básica e retratibilidade. Procurou-se investigar as diferenças entre as propriedades físicas em diferentes posições de colmos (base, meio, topo) de diferentes idades (1, 3 e 5 anos), visando a melhor utilização dessa matéria-prima. Os resultados mostraram que não houve interação significativa entre os fatores “idade” e “posição” para as propriedades teor de umidade e densidade básica, de acordo com a ANOVA em arranjo fatorial (95% de probabilidade). O teor de umidade diminuiu com o aumento da idade e da base para o topo, enquanto que a densidade básica aumentou com a idade e da base para o topo. A interação significativa entre os fatores “idade” e “posição” somente foi observada para a retratibilidade. A porção menos estável foi o topo dos bambus com cinco anos de idade, onde se encontraram maiores valores para a contração radial, tangencial e volumétrica. A porção basal na idade de três anos revelou-se a mais estável em contração volumétrica e tangencial. As porções base e topo na idade de um ano foram as mais estáveis quanto à contração radial. Palavras-chave: Phyllostachys pubescens; bambu-mossô; propriedades físicas. Abstract Physical properties of moso bamboo (Phyllostachys pubescens Mazel ex H. de Lehaie) at different ages and culm positions. The searching for renewable material with low environment impact put bamboo forward as a material that promotes the sustainable development due to its fast growing and that is not necessary to replant after harvesting. The aim of this study was to evaluate the following physical properties at different culm positions (base, middle and top) and ages (1, 3 and 5 years old) of moso bamboo (Phyllostachys pubescen Mazel ex H. de Lehaie): moisture content, basic density and shrinkage. The results showed that there was no significant interaction between the factors “age” and “position” for moisture content and basic density according to ANOVA in factorial arrange (95% of probability). Moisture content decreased with the increase of age and from base to top, while basic density increased with age and from base to top. Significant interaction between the factors “age” and “position” was only observed for shrinkage test according to ANOVA in factorial arrange. The portion less stable was the top of bamboo with five years old, which presented the highest radial, tangential and volumetric shrinkages. The basal portion of three years old was the most stable in volumetric and tangential shrinkage. The portions of base and top of one year old were the most stable in radial shrinkage.Keywords: Phyllostachys pubescens; moso bamboo; physical properties.