What Is the Supply and Demand for Coloured Wood Products? An Empirical Study in Slovakian Practice

The paper deals with the issue of the colour tones of wood and furniture products. The main aim is to identify the supply of the colour tones of wood and furniture products and to map the interest in these wood colour tones at potential customers in Slovakia. By means of two independent surveys of supply and demand for colour tones of wood and furniture products, various shortcomings have been identified. It is necessary to increase the supply of wood and furniture products with the natural colour of the wood and at the same time in colour tones of grey, white and brown. The current demand for thermowood and modified alder wood is significantly higher than the supply of such products in the Slovak market. The results of the study represent an opportunity for Slovak woodworking and furniture enterprises to adjust their range of products according to the needs of potential customers, which will bring them higher turnover and help to overcome the current problems associated with the “COVID crisis”.

Variation of Heartwood Proportion and Wood Colour from Fast Grown 5-Year-Old Teak

The heartwood percentage and wood colour of fast plantation grown teak destined for harvest at 5 years of age were characterized using automatic image processing ’ImageJ’ routines and CieLab’s colour system with the following coefficients: L for lightness, a* for redness and b* for yellowness. Analyses were conducted on material from different dry and wet sites. Comparison with 6-year old plantation from a dry site was conducted to study differences arising in older trees. Analyses of variation of those properties between and within different tree diameter classes were also conducted. The results showed that brightness, redness and yellowness values of 5-year old teak trees were 60.7, 10.7 and 23.1, respectively. Tree clone had a more dominant effect on wood colour and heartwood proportion than site, thus if specific colour preferences are needed of plantation trees, clone selection is important. The drier site produced larger proportions of heartwood in trees, as well as a more attractive figure. The trees produced heartwood proportions of 20% and 14% from the dry and wet sites respectively. On average, these 5 year old teak trees already produced 18% heartwood. Faster tree growth (larger diameter) appeared to have produced significantly larger heartwood proportions. Radially, the palest colour (the highest L but the lowest a*b* parameters) occurred in an area between heartwood and sapwood indicating the presence of a transition zone in all the tree samples.

Relationship Between Wood Colour of Seven Tropical Hardwood Species and Formaldehyde Emission of Plywood

There are many factors that affect the formaldehyde emission from plywood such as wood species and moisture content. As for wood species, colour appearance was found to affect significantly the formaldehyde emission. Therefore, the effects of tropical wood species with different colour on the formaldehyde emission of manufactured plywood were studied and determined by the perforator and desiccator method. Veneer of seven wood species, namely Mempisang, Kedondong, Penarahan, Keledang, Rengas, Melembu and Ludai were chosen as samples. 3-ply plywood were manufactured using urea formaldehyde as binders. The formaldehyde emission of the produced plywood was tested using perforator method (EN 120) and desiccator method (MS 1787: Part 15). Colour of the wood veneers were measured using Brightness & Colour Meter through CIE L*a*b* system. Relationship between the wood colour and formaldehyde emission were determined. The results revealed that the formaldehyde emission increased as the lightness (L*) of the wood samples increased. This may be due to higher extractive content in darker coloured wood (low lightness) that acts as formaldehyde scavenger.

The dead forest on Trindade Island was not monospecific, says the wood

The first reports of a dead forest on Trindade Island are from the 18th century. Since then, the tentative identifications of the trees with red wood included Caesalpinia, Acacia, Rapanea, Pisonia, Eugenia and Colubrina, the latter having been confirmed by three independent wood anatomists familiar with Brazilian woods. In the 1960s Johann Becker was the last to sample a live Colubrina glandulosa Perkins var. reitzii on Trindade, which was presumed to be a remnant of the extinct forest. Based on this information, along with the eradication of feral goats from the island in 2005, thousands of C. glandulosa seedlings were reintroduced to Trindade. These trees, which grew well at first, are now collectively dying, less than two decades after planting. Their wood colour is much lighter than that of the dead trees, raising doubts about the latter’s correct identification. Herein we report the first detailed descriptions of two wood types from the extinct forest of Trindade, confirming the presence of C. glandulosa and reporting the presence of Paratecoma peroba (Bignoniaceae), a novel occurrence for the island. Radiocarbon dating of a dead C. glandulosa tree confirms that it belongs to the forest which died three centuries ago. The preserved wood proves that the extinct forest was not monospecific and suggests that further sampling of the remaining dead wood may enhance the floristic knowledge of the forest which once covered most of the island with additional species.