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

Abstract

RESUMOAvaliaram-se os efeitos do teor de umidade e classe diamétrica na qualidade do tratamento de moirões de Corymbia torelliana e Eucalyptus grandis x Eucalyptus urophylla. Utilizaram-se 108 moirões, sendo 36 tratados e 18 não tratados, com 2,20 m de comprimento e umidade de 15 a 20%; 20 a 30%; 30 a 40%, e diâmetros de 8 a 10 cm; 10 a 12 cm; 12 a 14 cm. No tratamento, foram utilizados 2% de ingredientes ativos de CCA-C, vácuo inicial e final de 550 mmHg (30 min), pressão de 11 kgf cm -2 (1 h). Os moirões tiveram a umidade avaliada pelo medidor elétrico, que foi adequado para estimar a umidade destes. Obtiveram-se penetrações satisfatórias e a maior retenção foi obtida nos moirões com umidade de 15 a 20% (8,23 kg m -3 ), contudo, umidade de 30 a 40% também foi adequada ao tratamento da madeira, obtendo valores superiores a 6,5 kg m -3 .Palavras-chave: tratamento de moirões, arseniato de cobre cromatado, penetração, retenção. Influences of Diameter and Wood Moisture on Quality of the Preservative Treatment ABSTRACTWere 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 .

Influence of CCA-A preservative on physical-mechanical properties of Brazilian tropical woods

“…As a solution, fast-growing tropical species that have a medium to low density are gradually being used more in the Brazilian timber market. However, such species are more susceptible to deterioration and require conservative treatment (Paes et al 2001;Lopes et al 2017). The main wood products in Brazil that are subject to this treatment include fence posts (with great representation in rural areas), poles, crosses, wooden crossties, and structures for civil construction (Chagas et al 2015).…”

CCB Retention and Penetration in Eucalyptus Fence Posts in Function of Condition of Preservative Treatment

“…The concentrations and pressure times used in this study were defined as being the parameters commonly used in the country's wood treatment plants (TORRES et al, 2011;LOPES et al, 2017). After the preservative treatment at the different concentrations and times, the fence posts were dried outdoors for 30 days for the preservative fixation.…”

“…Wood is a material of organic origin, and depending on the environmental conditions to which it is submitted it might be deteriorated by biological degradation agents (bacteria, fungi, insects), as well as by chemical reactions (LOPES et al, 2017). When used in its solid form (e.g., fence posts), the wood in contact with the soil undergoes an interaction of moisture and aeration in such context , favoring the development of fungi (VIDAL et al, 2015;SILVEIRA et al, 2018).…”

“…After the application of the preservative solution, retention and penetration tests are adopted to verify the success of the treatment (VALLE et al, 2013, AMARAL et al, 2014LOPES et al, 2017). The retention analysis is classified by categories of wood use expressed by ABNT NBR 9480 (ASSOCIAÇÃO BRASILEIRA DE NORMAS TÉCNICAS, 2009).…”

“…According to this standard, minimum retention of the preservative solution for fence posts in direct contact with soil is 6.5 kg of active ingredient per m 3 of wood. The penetration analysis can either be performed qualitatively (SALES-CAMPOS et al, 2003) by observing depth levels, or quantitatively (LOPES et al, 2017), being considered satisfactory when reaching at least 1.0 cm of penetration.…”