Effect of Heat Treatment on the Physic-Mechanical Characteristics of Eucalyptusurophylla S.T. Blake

Eucalyptus plantations wood have great potential application in high quality solid wood product. In order to improve the overall characteristics, heat treatments (HT) were carried out using Eucalyptus urophylla S.T. Blake wood at 150, 170 and 190 °C, for 2 and 4 h, separately. The effects of HT on physical and mechanical properties, wood color, dimensional stability and chemical change were investigated. The results indicate that: Mass loss (ML) of wood at a moderate temperature of 150 °C was small, but increased remarkably when temperature exceeds 170 °C. A maximum ML of 5.83% was observed at 190 °C/4 h; the velocity of water vapor adsorption and equilibrium moisture content (EMC) of HT wood decreased significantly, and varied considerably with treating severity; absolute dry density of HT wood decreased, presenting a similar tendency with ML, but the reduction was greater than ML; HT reduced the tangential and radial swelling ratio and swelling coefficients of wood, and improved the dimensional stability by 71.88% at 190 °C; modulus of rupture (MOR) and modulus of elasticity (MOE) of HT wood varied significantly in severer conditions, but there were no obvious changes in a moderate conditions at 150 °C; there was a slight color change at 150 °C, but wood color became more dark and uniform with treating severity; HT decreased the relative content of hydroxyl groups in wood components, improving wood dimensional stability. Color change of wood may be caused by variations of chromophoric groups and its own structure of lignin due to HT. Moderate temperature HT at 150 °C improved dimensional stability and color uniform of wood, but without reducing mechanical stress. This is a practical HT condition for Eucalyptus urophylla S.T. Blake.

Review on Importance of Artocarpus heterophyllus L. (Jackfruit)

The Jackfruit (Artocarpus heterophyllus L.) is well-known as “poor man’s food” fruit in Bangladesh. It is widely consumed by most of the rural people and it is the national fruit of Bangladesh. The main aim of this review is to document the medicinal significance of jackfruit (Artocarpus heterophyllus L.), major parts and uses of the jackfruit in Bangladesh. This article was based on mostly a literature review. All parts of the fruit and plant are used as human food, animal feed and wood source for furniture. Although jackfruit is the main fruit of the tree, it is used as furniture for its beautiful texture and wood color. Jackfruit contains anti-bacterial, anti-diabetic, anti-oxidant, anti-inflammatory and anti-helminthic properties. The fruit is rich in carbohydrates, minerals, carboxylic acids, dietary fiber, vitamins and minerals. The seed is rich in manganese, magnesium, potassium, calcium iron and lectins and thus meets up nutritional requirements for the rural people. The present study attempted to review the medicinal importance, health-promoting effects of jackfruit and seeds with special emphasis on their applications in the food.

Comparison of the color and weight change in Paulownia tomentosa and Pinus koraiensis wood heat-treated in hot oil and hot air

Color changes were tested and compared for heat-treated Paulownia tomentosa and Pinus koraiensis wood treated with hot oil or hot air for further utilization of these species. Hot oil and hot air treatments were conducted at 180, 200, and 220 °C for 1, 2, and 3 h. Heat-treated wood color changes were determined using the CIE-Lab color system. Weight changes of the wood before and after heat treatment were also determined. The weight of the oil heat-treated wood increased considerably but it decreased in air heat-treated wood. The oil heat-treated samples showed a greater decrease in lightness (L*) than air heat-treated samples. A significant change in L* was observed in Paulownia tomentosa. The red/green chromaticity (a*) of both wood samples increased at 180 and 200 °C and slightly decreased at 220 °C. The yellow/blue chromaticity (b*) in both wood samples increased at 180 °C, but it rapidly decreased with increasing treatment durations at 200 and 220 °C. The overall color change (ΔE*) in both heat treatments increased with increasing temperature, being higher in Paulownia tomentosa than in Pinus koraiensis. In conclusion, oil heat treatment reduced treatment duration and was a more effective method than air heat treatment in improving wood color.

Effect of Ammonia Fumigation Treatment on Wood Color and Chemical Composition

Betula alnoides was used as a test material to study the effect of ammonia fumigation treatment on wood color and chemical composition. The effects of concentration, temperature, and duration of ammonia fumigation on wood color were studied. The properties of the material were studied using contact angle measurements, X-ray diffraction, Fourier-transform infrared spectroscopy, and dynamic thermomechanical analysis. In general, the color difference of the wood increased with the concentration of ammonia used in the fumigation process, treatment temperature, and treatment duration. After ammonia fumigation treatment, the chemical composition of hydroxyl and carboxyl groups in the wood was reduced. We concluded that ammonia fumigation treatment decreased material wettability and dynamic mechanical rigidity and increased the degree of crystallinity in wood.

Effects of vacuum heat treatment and wax impregnation on the color of Pterocarpus macrocarpus Kurz.

Pterocarpus macrocarpus Kurz. wood was vacuum heat treated (VHT) at 120, 150, and 180 °C, under a pressure of 13.3 kPa. Half of the VHT specimens at 120 and 150 °C were subjected to wax impregnation (WI) for 48 h at 90 °C under an atmospheric pressure. The effect of VHT and WI on wood color were investigated. The results showed that the VHT at 120 and 150 °C resulted in minor changes in lightness (L*), green-red chromatic coordinate (a*), blue-yellow chromatic coordinate (b*), total color change (ΔE*), and chroma (C*). However, the effect of VHT on L*, a*, b*, and C* at 180 °C became more obvious over the duration. After WI, the L*, a*, b*, and C* of the VHT wood at moderate temperatures varied noticeably, showing similar behavior with the VHT wood at 180 °C as L*, b*, and C* decreased and ΔE increased. However, a* increased after WI compared to that of VHT at 180 °C. The wood color of P. macrocarpus Kurz. after WI became reddish and blue, and the color deviation decreased. The wood color was closer to the dark mahogany, which facilitates its further application in rosewood furniture and woodwork art.

Color variance of dry coconut wood and its relationship with the density

The color variance of dry coconut wood and its relationship with the wood density was explored. Coconut trunks with two different ages of 30 and 60 years old were selected for the experiment. Wood color was measured by the CIE L*a*b* or CIELAB color system on both the transverse (longitudinal-tangential plane) and cross (tangential-radial plane) sections. The results showed that all color parameters (L*, a*, b*) tended to decrease with increasing wood density for both sections in which the value on transverse section was slightly higher. At a given density, the color value of the older trunk was lower. All color parameters appeared to be related with density in a linear relationship with relatively low R2 for both ages. The best correlation was observed for the b*-density relationship on cross sectional samples for both trunk ages, showing R2 values of 0.53 to 0.60. This implies that it might be possible to use this color parameter as input for the grading of coconut wood’s density.

Wood Properties of 5-year-old Fast Grown Teak

Jati Unggul Nusantara (JUN) is one of fast growing plantation teak that has been widely cultivated in Indonesia. This teak has been developed to be harvested after 5 years when its diameter reaches 25-32 cm (diameter at breast high). The diameter of JUN is usually three times larger than the conventional plantation teak (teak cultivated from seed) at the same age, and the same as 30-40 year-old mature teak. Preliminary research was conducted to determine anatomical and selected physical properties of 5-year-old JUN teak, as well as its suitability for furniture production. The results revealed that wood color, texture, and grain pattern of JUN were slightly different from the mature conventional teak. The length of fiber cells was similar as in the mature teak. There were differences in ultramicroscopic structure of JUN: the mean micro fibril angle was narrower, and the crystallites degree was larger. Shrinkage values from green to 12% moisture content were: 0.70 (radial-R) and 1.62 (tangential-T), and from green to oven dry were 1.59 (R) and 3.29 (T). T/R ratio was 2.34. Specific gravity in air dry condition was 0.52. Based on the research results it appears that 5-year-old JUN may be suitable for the production of medium quality furniture products. More research is required to investigate and enhance the properties of JUN for high quality products.

Stain capacity of three fungi on two fast-growing wood

We investigated the stain of fast-growing wood (Cunninghamia lanceolate, CL; Paulownia, PT) inoculated with three fungi (Arthrinium phaeospermum, AP; Vibrio anguillarum, VA; Aspergillacea, AS) to explore the new wood dyeing ways and the better combination of wood and fungi for dyeing. Only AP could dye on CL and PT. Especially for CL, its percentage of internal spalting, percentage of external spalting and dyeing depth were the highest (48%, 15% and 5.06 mm, respectively). Surprisingly, the bigger weight loss occurs on PT. The results showed that the dyeing effect of AP dyeing CL was the best, and the wood color change was obviously (Orange to dark red). AP could produce more pigments than the other two fungi (VA; AS), CL was more suitable for fungus staining than PT, indicating that AP could offered a new potential market and a chance for areas to earning higher income for CL. This research paves the way for improving color change was obviously (Orange to dark red). AP could produce more pigments than the other two fungi (VA; AS), CL was more suitable for fungus staining than PT, indicating that AP could offer a new potential market and a chance for areas to earn higher income for CL.