PAPER making! g! FROM THE PUBLISHERS OF PAPER TECHNOLOGY INTERNATIONAL ® Volume 11, Number 1, 2025
the minimum bounding rectangle algorithm was used to measure characteristics of each strand. Based on the results obtained from manual measurement, the performance of the automatic method was evaluated. In laboratory tests, this method presents great performance in extracting and distinguishing characteristics of strands. This method also shows good adaptability for production line application. In the production line, around 80% of strands can be correctly extracted and distinguished, with a strong correlation between manual measurements and automatic method results (R2 > 0.97). It takes 37.7ms to process one image containing approximately 500 strands. Strand orientation in the production line nearly concords with normal distribution (N (-1.25, 30.52)). The size of strands significantly affects the relative intensity of the strand orientation (with P < 0.05). There is a positive and linear relationship between the strand size and the orientation of strands. The outputs of this study contribute to a better understanding and management of OSB manufacture in the production line. “ Metallic contaminants in wood panel production process: Evaluating press plate damage and detecting potential using IR thermography and spectroscopy ”, International Journal of Damage Mechanics , online 2025. In the wood panel industry, metallic contaminants raise significant concerns, especially regarding the press plate's surface integrity, which requires a thorough inspection. This study investigated the effect of metallic contaminants on press plate damage and evaluated the use of infrared thermography (IRT) and infrared (IR) spectroscopy as non-destructive testing (NDT) methods for detecting these contaminants in wood panel manufacturing. Metallic contaminants embedded within lab-scale wood panels demonstrated their impact on the surface quality of both the press plate and the resulting panels. Moreover, confocal laser microscope analysis revealed that the surface roughness of the press plate surface was influenced by the specific alloy composition of contaminants, with steel and chromium contaminants exhibiting the more severe damage (e.g., mean roughness values of 59,80 and 84,64 μm, respectively). Thermography images exhibited the efficacy of IRT in detecting contaminants close to the surface of thin panels. However, an advanced camera is recommended for thicker panels and deeper contaminants to obtain a more accurate inspection. The Fourier-transform infrared spectroscopy (FTIR) evaluation revealed the presence of the metal- oxygen vibration band at approximately 668 cm −1 across all alloy compositions, suggesting its potential as a reliable reference for detecting metallic contaminants. “ The impact of altering the molar ratio on formaldehyde content and the physical and mechanical properties of MDF panels ”, Camila Alves Corrêa, Alexsandro Bayestorff da Cunha, Polliana D’Angelo Rios, Matheus Zanghelini Teixeira & Gefferson Costa de Liz, Journal of Adhesion Science and Technology , Vol.39(2), pp.226-243, 2025. This study aimed to evaluate the influence of the molar ratio of urea-formaldehyde resin (UF) on formaldehyde content and the physical and mechanical properties of MDF panels. The goal was to determine the optimal composition, i.e. the one that exhibits the lowest formaldehyde content without compromising the properties. To that end, there were five treatments. They were characterized by five F:U molar ratios (0.9:1; 1.0:1; 1.1:1; 1.2:1; and 1.3:1). The panels had a nominal density of 750 kg.m −3 , dimensions of 40 × 40 × 1.5 cm, 12% resin, 1% paraffin. They were produced with a pressing cycle with a temperature of 170 °C and pressure of 3.6 MPa per 10 min. The physical -mechanical properties of the panels and the formaldehyde content were determined and evaluated following the NBR 15316-2 (2019) standard. Results showed that the formaldehyde content was lower for panels produced with resin molar ratios of 0.9:1, 1.0:1, and 1.1:1, classified as E1. Panels with a resin molar ratio of 1.2:1 were classified as E2. The molar ratio of 1.3:1 exceeded the limits of the standard.
Technical Abstracts
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