Produção de painéis compensados com resina fenólica e melamínica sem formaldeído

O objetivo desta pesquisa foi avaliar o potencial técnico de duas resinas sem formaldeído para a produção de compensados laminados para ambiente interno e externo não abrigado. Para tanto, as resinas foram comparadas com as tradicionalmente utilizadas pelo setor. O plano experimental foi composto por 05 tratamentos, sendo: com resina fenol sem formaldeído (T1) e com formaldeído (T2), com resina melamina uréia com formaldeído (T3) e sem formaldeído (T4), e com resina uréia formaldeído (T5). Foram produzidos painéis compensados laminados com 07 lâminas de 2,7 mm, com composição do adesivo e parâmetros de processo conforme recomendado pelos fabricantes das resinas. Os resultados das propriedades tecnológicas dos painéis foram inicialmente submetidos a testes de normalidade dos dados e homogeneidade das variâncias, e na sequência avaliados por meio da análise de variância e teste de Scott Knot a 95% de probabilidade. Observou-se que para ambiente externo não abrigado, a resina melamínica uréia sem formaldeído demonstrou potencial de utilização; já a resina fenólica sem formaldeído (em pó) apresentou resultados pouco expressivos. Para ambiente interno, a resina melamínica uréia sem formaldeído se apresentou como potencial técnico para substituição da uréia formaldeído

FEASIBILITY OF USING Zanthoxylum ekmanii (Urb.) Alain FOR PLYWOOD PANEL PRODUCTION

Feasibility of using Zanthoxylum ekmanii (Urb.) Alain for plywood panel production.The demand for wood-based products by society is growing because these products are less restrictive, highly resistant, and reliable in use. However, due to a lack of technological knowledge, the number of Amazonian species used within the timber industries is still limited. Therefore, knowing the potential use of these species is important to the forestry sector’s development. In this context, this study aimed to evaluate the physical and mechanical properties of plywood panels produced with veneer sheets of Zanthoxylum ekmanii (lemon) and its combination with Pinus sp., using the urea-formaldehyde (UF) and (PF) phenol-formaldehyde resins. Panels were produced with 15 mm, dimensions of 50 x 50 cm, and a grammage of 360 g/m2 in a single line. Physical and mechanical tests were performed by the specifications described in the Brazilian standards. The results were compared to the requirements of the ABIMCI technical catalog and the NBR ISO 12466-2 standard. The homogeneous and combined panels with Z. ekmanii evaluated in this study presented results of water absorption, thickness swelling, compression set recovery, glue line shear strength, and parallel and perpendicular static bending statistically equal to or superior to the reference species (Pinus sp.). Therefore, the panels produced with Z. ekmanii have good quality in bonding with UF and PF resins. This species can be used in the production of homogeneous plywood or combination with Pinus sp

Applying colorimetry for wood differentiation of fabaceae species grown in southern brazil

Because of the need for identification of forest species, especially for detection of illegal wood trade, the objective of this study was to evaluate the potential of colorimetry for differentiation of Inga vera Willd., Muellera campestris (Mart. ex Benth.) M.J. Silva & A.M.G. Azevedo and Machaerium paraguariense Hassl., species of the Fabaceae family, native to the Araucaria Forest in the state of Santa Catarina, southern Brazil. Discs at breast height were collected from three trees of each species and the colorimetric parameters (L*, a*, b*, C* and h) and visible spectra were evaluated in different radial position of the trunk (near bark, intermediate and near pith) and three different anatomical sections (transversal, radial and tangential surfaces). Mean values of hue angle (h) among the colorimetric parameters resulted in the highest potential for species discrimination. With respect to radial trunk position and anatomical section, parameters a* (green-red) and h were not statistically different, independent of the wood samples evaluated. For other parameters (L*, b* and C*), each species presented distinct results. Principal component analysis with second derivative of visible spectra discriminated all species. Colorimetry associated with chemometrics allowed to distinguish I. vera, M. campestris and M. paraguariense

ATRIBUTOS FUNCIONAIS DE ESPÉCIES ARBÓREAS EM UM FRAGMENTO DE FLORESTA OMBRÓFILA MISTA EM LAGES - SC

This study aimed to describe the functional traits of tree species in an Araucaria Forest fragment, in the municipality of Lages, SC state, in order to group them functionally. For each of the 20 most abundant species in the study area, a total of 10 individuals were sampled for the determination of the mean wood density and mean leaf size. The leaf renovation regimes, the dispersal syndrome and the maximum height in the fragment were also described for these species. The results of maximum height and wood density suggest the existence of a trade-off between investment of resources in height growth, ensuring access to some higher light availability, or in wood density, allowing for greater resilience and survival in a shaded understory environment. The gymnosperm species, Podocarpus lambertii and Araucaria angustifolia showed smaller leaves, while Cupania vernalis, Jacaranda puberula and Matayba elaeagnoides, all of compound leaves, had larger ones. Four functional groups stood out: 1) Evergreen with large leaves, 2) Evergreen with small leaves, 3) Deciduous with zoochoric syndrome, and 4) Deciduous with non-zoochoric syndrome. The results showed that the most abundant species of the studied Araucaria Forest fragment present functional trait variations, suggesting different life strategies.O presente estudo teve como objetivo descrever atributos funcionais de espécies arbóreas em um fragmento de Floresta Ombrófila Mista em Lages - SC, com o propósito de agrupá-las funcionalmente. Para cada uma das 20 espécies mais abundantes na área de estudo foi amostrado um total de 10 indivíduos e determinada a média da densidade da madeira e o tamanho médio das folhas. Dessas espécies, também foi descrito o regime de renovação foliar, a síndrome de dispersão de propágulos e a altura máxima no fragmento. Os resultados de altura máxima e de densidade da madeira sugerem a existência de um trade-off entre o investimento de recursos para o crescimento em altura, garantindo o acesso à maior disponibilidade lumínica, ou em densidade da madeira, permitindo maior capacidade de resistência e sobrevivência em um ambiente sombreado de sub-bosque. As gimnospermas Araucaria angustifolia e Podocarpus lambertii apresentaram as folhas de menor tamanho, enquanto Cupania vernalis, Jacaranda puberula e Matayba elaeagnoides, todas de folhas compostas, apresentam as maiores folhas. Quatro grupos funcionais se destacaram: 1) perenes de folhas grandes, 2) perenes de folhas pequenas, 3) decíduas zoocóricas e 4) decíduas não zoocóricas. Os resultados demonstraram que as espécies mais abundantes do fragmento de Floresta Ombrófila Mista estudado apresentam variações dos atributos funcionais avaliados, sugerindo diferentes estratégias de vida.

Active food packaging of cellulose acetate : storage stability, protective effect on oxidation of riboflavin and release in food simulants

In this work, cellulose acetate films were prepared with the incorporation of different carotenoids (lycopene, norbixin, and zeaxanthin). The effect of adding these natural antioxidants was evaluated through stability during storage under controlled conditions (temperature and light), degradation rate coefficient, release in food simulants and protective effect on oxidation of vitamin B2. During storage at 25 °C or 40 °C the light showed a greater effect on the stability of the carotenoids, with significant increase in reaction constants (k) and decrease in half-life (t1/2). The degradation of the carotenoids was followed by a variation in the color parameters and mechanical properties. The films with norbixin showed the highest barrier to the transmission of UV–Vis light, consequently preserving 72% of a vitamin B2 stored under a photooxidative environment. Lycopene presented a higher release rate than norbixin and zeaxanthin to a fatty food simulant

Near-infrared spectroscopy for the distinction of wood and charcoal from Fabaceae species: comparison of ANN, KNN AND SVM models

Aim of study: The objective of this work was to evaluate the potential of NIR spectroscopy to differentiate Fabaceae species native to Araucaria forest fragments.Area of study; Trees of the evaluated species were collected from an Araucaria forest stand in the state of Santa Catarina, southern Brazil, in the region to be flooded by the São Roque hydroelectric project.Material and methods: Discs of three species (Inga vera, Machaerium paraguariense and Muellera campestris) were collected at 1.30 meters from the ground. They were sectioned to cover radial variation of the wood (regions near bark, intermediate and near pith). After wood analysis, the same samples were carbonized. Six spectra were obtained from each specimen of wood and charcoal. The original and second derivative spectra, principal component statistics and classification models (Artificial Neural Network: ANN, Support Vector Machines with kernel radial basis function: SVM and k-Nearest Neighbors: k-NN) were investigated.Main results: Visual analysis of spectra was not efficient for species differentiation, so three NIR classification models for species discrimination were tested. The best results were obtained with the use of k-NN for both wood and charcoal and ANN for wood analysis. In all situations, second derivative NIR spectra produced better results.Research highlights: Correct discrimination of wood and charcoal species for control of illegal logging was achieved. Fabaceae species in an Araucaria forest stand were correctly identified.Keywords: Araucaria forest; identification of species; classification models.Abbreviations used: Near infrared: NIR, Lages Herbarium of Santa Catarina State University: LUSC, Principal component analysis: PCA, artificial neural network: ANN, support vector machines with kernel radial basis function: SVM, k-nearest neighbors: k-NN

Near-infrared spectroscopy for the distinction of wood and charcoal from Fabaceae species: comparison of ANN, KNN AND SVM models

Aim of study: The objective of this work was to evaluate the potential of NIR spectroscopy to differentiate Fabaceae species native to Araucaria forest fragments. Area of study; Trees of the evaluated species were collected from an Araucaria forest stand in the state of Santa Catarina, southern Brazil, in the region to be flooded by the São Roque hydroelectric project. Material and methods: Discs of three species (Inga vera, Machaerium paraguariense and Muellera campestris) were collected at 1.30 meters from the ground. They were sectioned to cover radial variation of the wood (regions near bark, intermediate and near pith). After wood analysis, the same samples were carbonized. Six spectra were obtained from each specimen of wood and charcoal. The original and second derivative spectra, principal component statistics and classification models (Artificial Neural Network: ANN, Support Vector Machines with kernel radial basis function: SVM and k-Nearest Neighbors: k-NN) were investigated. Main results: Visual analysis of spectra was not efficient for species differentiation, so three NIR classification models for species discrimination were tested. The best results were obtained with the use of k-NN for both wood and charcoal and ANN for wood analysis. In all situations, second derivative NIR spectra produced better results. Research highlights: Correct discrimination of wood and charcoal species for control of illegal logging was achieved. Fabaceae species in an Araucaria forest stand were correctly identified