Ivaldo Pontes Jankowsky

Review of Wood Drying Research in Brazil: 1984–2004

In Brazil, research on wood drying has been more focused on applied aspects than on fundamentals ones, and results have been published almost exclusively in Brazilian journals. The study of lumber deformation under aggressive drying conditions resulted in methods to group species and to define kiln schedules. Relationship between moisture content and electrical resistivity was used to improve quality control of dried lumber as well automatic control of the kiln drying process. Conventional kiln drying is the most common method for industrial drying, but seasoning and solar drying were also studied. The biggest research effort was directed to improve the drying of eucalypt lumber.

Drying behavior and permeability of Eucalyptus Grandis Lumber

Although the increasing economic importance of Eucalyptus lumber to furniture and other value added products manufacturing, its industrial use is still small. One of the main reasons is the difficulty to dry the lumber and related loses of row material. There is a general recommendation in literature to use a low drying rate in initial stages of the process, and changing to a more aggressive drying after removal of liquid water from the lumber. According classical theory about drying of porous material, this point should coincide with the predominance of diffusion phenomena in the moisture movement; which could be determined through the characteristic drying curve of the material. With the objective to get better knowledge about the drying of Eucalyptus grandis lumber, its characteristic drying curve was determined, and the results proved that Eucalyptus grandis lumber is not permeable to liquid flow. Based on its characteristic drying curve, it is possible to suggest the change of drying conditions when lumber moisture content, dry basis, is between 35% and 40%, then starting a more aggressive drying.

PRESERVAÇÃO DE MADEIRAS NO BRASIL: HISTÓRICO, CENÁRIO ATUAL E TENDÊNCIAS

The objective of this paper was to show a comprehensive literature review about wood preservation in Brazil, since the earliest years until 2011. Brazil is rich in natural resources and wood has always occurred in abundance. With the industrial growing, there was the necessity of using wood with low natural durability but with chemical preservative treatment. Wood chemical treatment began in late XIX century, mainly to attend the big demand of sleepers to railroads. Only during the 60s, wood preservation gained market with the increase of scientific researches, elaboration of technical standards and building industrial plants for wood preservation. From this point on, few advances have been reached. In 2011, Eucalyptus and Pinus, were the main species used in wood preservation plants that adopts the vacuum-pressure process. In small production scale, diffusion process is adopted. Copper chromium arsenate (CCA) and Copper chromium borate (CCB) are the most preservatives utilised with some creosote utilisation. The treated wood production is concentrated in fence posts, poles and sleepers. As a trend, the wood preservation must reach new markets, such as building constructions, wood packages and crossarms, and also to intensify the traditional uses. Although there are a lot of researches about chemicals for wood preservation, CCA must keep by the years, once alternative products do not present the same efficacy or clear effects about human health and environment.

Wood preservation in Brasil: historical, current scenario and trends

The objective of this paper was to show a comprehensive literature review about wood preservation in Brazil, since the earliest years until 2011. Brazil is rich in natural resources and wood has always occurred in abundance. With the industrial growing, there was the necessity of using wood with low natural durability but with chemical preservative treatment. Wood chemical treatment began in late XIX century, mainly to attend the big demand of sleepers to railroads. Only during the 60’s, wood preservation gained market with the increase of scientific researches, elaboration of technical standards and building industrial plants for wood preservation. From this point on, few advances have been reached. In 2011, Eucalyptus and Pinus, were the main species used in wood preservation plants that adopts the vacuum-pressure process. In small production scale, diffusion process is adopted. Copper chromium arsenate (CCA) and Copper chromium borate (CCB) are the most preservatives utilised with some creosote utilisation. The treated

Influências do Diâmetro e Umidade da Madeira na Qualidade do Tratamento Preservativo

Were evaluated the effects of moisture content and diametric class in industrial treatment quality of Corymbia torelliana and Eucalyptus grandis x Eucalyptus urophylla fence posts. 108 fence posts were used, 36 treated and 18 non-treated, with 2.20m long and moisture content of 15 to 20%; 20 to 30%; and 30 to 40% and diameters of 8 to 10cm; 10 to 12cm; 12 to 14cm. For treatment, were used 2% active ingredients of CCA-C, initial and final vacuum 550 mmHg (30min), pressure of 11 kgf cm-2 (1h). The fence posts were evaluated by electric meter that was adequate to estimate the moisture. Satisfactory penetrations were obtained and the biggest retention was reached in fence posts with moisture of 15 to 20% (8.23 kg m-3), however, the moisture content of 30 to 40% was also suitable for the treatment of wood, getting values higher than 6.5 kg m-3.

Pontos críticos do processo de produção de pisos maciços de madeira

Os conceitos da qualidade representam um dos fatores importantes para o exito das organizacoes, e dentre esses conceitos a estabilizacao dos processos de producao contribui para a melhoria, reducao de desperdicios e aumento da competitividade. Com isso, o objetivo desse trabalho foi avaliar o processo de producao de pisos macicos de madeira de especies comerciais quanto a sua previsibilidade e capacidade, com base em seus pontos criticos. Para tanto, a pesquisa foi dividida em tres etapas. A primeira foi o mapeamento do processo da empresa e a elaboracao de fluxogramas para as atividades. A segunda foi a identificacao e a avaliacao dos pontos criticos por meio da metodologia FMEA (Failure Mode and Effect Analysis) adaptada. A terceira foi a avaliacao dos pontos criticos empregando o controle estatistico e a determinacao da capacidade do processo pelo indice Cpk. Os resultados mostraram a existencia de seis processos, sendo dois identificados como criticos. Nesses dois, quinze pontos foram considerados criticos e dois deles, relacionados com as dimensoes das pecas e defeitos provocados pela lixa, foram selecionados para avaliacao. O processo produtivo da empresa e instavel e nao e capaz de produzir os pisos dentro das especificacoes e, portanto, essas especificacoes devem ser reavaliadas.