Danillo Wisky Silva

Use of maize cob for production of particleboard

Os residuos agricolas sao materiais gerados em grande quantidade no Brasil, podendo se acumular no ambiente, gerando graves problemas. Um desses residuos que merecem destaque e o sabugo de milho. Uma das alternativas para o reaproveitamento do sabugo seria a producao de paineis aglomerados em mistura com madeira. Objetivou-se, neste trabalho, avaliar a viabilidade da utilizacao do sabugo de milho para a producao de paineis aglomerados. As porcentagens de sabugo de milho utilizadas foram de 0%, 25%, 50%, 75% e 100% associadas com particulas de madeira de Pinus oocarpa. Os paineis foram produzidos com 8% de ureia-formaldeido e 1% de parafina (base massa seca de particulas). Na prensagem dos paineis, foi utilizada pressao de 3,92 MPa e temperatura de 160o C por um periodo de 8 minutos. O aumento da substituicao da madeira de pinus pelo residuo sabugo de milho promoveu melhoras significativas para as propriedades de absorcao de agua, apos duas horas e inchamento em espessura, apos duas e vinte e quatro horas. As propriedades mecânicas apresentam relacao decrescente com a porcentagem de incorporacao de sabugo de milho.

Use of Castor Hull and Sugarcane Bagasse in Particulate Composites

Particulate composites can be manufactured using low-quality raw materials, thus presents the option of using various non-wood materials, including agricultural waste. This study aimed to evaluate the effect of using castor hull and sugarcane bagasse on the physico-mechanical properties of particulate composites. Particleboards were produced using raw materials such as Pinus oocarpa wood, castor hull (Ricinus communis), and sugarcane bagasse (Saccharum officinarum) in different proportions: 1) 100% P. oocarpa wood; 2) 100% castor hull; 3) 100% sugarcane bagasse; 4) 50% P. oocarpa wood and 50% castor hull; and 5) 50% P. oocarpa wood and 50% sugarcane bagasse. The produced panels had a nominal density of 0.70 g/cm3, 8% urea-formaldehyde adhesive, specific pressure of 3.92 MPa, temperature of 160°C, and pressing time of 8 min. The panels produced with sugarcane bagasse, with or without pine wood, showed better dimensional stability. The panels produced with sugarcane bagasse only or with castor hull only showed the lowest values of modulus of rupture and elasticity to the bending. However, despite these differences among the treatments, all treatments met the requirements of the EN 312 (2003) standard for internal use panels.

Functionally Graded MDP Panels Using Bamboo Particles

MDP (medium density particleboard) panels are normally graded in composition along their cross-section, using low-size particles and high concentration of adhesive on the particleboard surface (leading to improved physical and mechanical properties), and high-size particles in the particleboard core (interior), which provide higher porosity. Then, the aim of this study was to evaluate the impact of using different contents of bamboo particles in the particleboard core, on their physical and mechanical properties. The production of the panels was carried out using Pinusoocarpa (P) and Bambusavulgaris var. Vittata (B) particles in different contents (100% P, 100% B, 50% de B e 50% de P, 25% de B e 75% de P, 75% de B e 25% de P) in the core of the particleboards. The face of the particleboards were composed of P particles. The panels were produced with nominal density of 0.70 g/cm3, 40:60 face:core relation, 11% urea-formaldehyde adhesive in the faces and 8% adhesive for the core, specific pressure of 3.92 MPa, 160 °C temperature and pressing time of 8 min. After seasoning, the panels were submitted to evaluation of the thickness swelling (TS) and water absorption (WA) after 2 and 24 h of immersion, apparent density (AD), internal bonding (IB), modulus of rupture (MOR) and modulus of elasticity (MOE) under static bending. There was no statistical difference between the treatments for AD, IB, MOR and MOE values. Panels produced with high contents of bamboo particles (100% B, 75% B e 50% B) in the core, presented the lower WA and TS values, leading to improved dimensional stability than panels with only pinus particles. The present results show the important impact of using functionally gradation and bamboo particles on the physical properties of the MDP panels produced.

Cementitious Composites Reinforced with Kraft Pulping Waste

Kraft pulping is currently the most widely used technique in the production of cellulose pulp, and the production process generates large amount of lignocellulosic residues. Looking to add value to this residue, the aim of this study was to evaluate the physical and mechanical properties of extruded cementitious matrices reinforced with lignocellulosic waste from the kraft pulping of Eucalyptus spp wood. The experimental design were consisted of 3 treatments with 5 samples for each treatment, as follows: 1) 70% Portland cement (by mass) with 30% ground carbonate (by mass) - T1; 2) 66.5% of Portland cement, 28.5% ground carbonate and 5% residual pulp fibers - T2, and 3) 69.5% Portland cement, 25.5% metakaolin and 5% residual pulp fibers - T3. The mass for extrusion was prepared with the addition of hydroxypropyl-methylcellulose (HPMC) and polyether carboxylic (ADVA) as rheology modifiers, with water:cement ratio of around 0.3. After mixing, the mass was taken to an extruder where the specimens were obtained. Apparent porosity (AP), bulk density (BD), water absorption (WA), modulus of rupture (MOR), fracture toughness (KIC) and fracture energy (EF) were evaluated. There was statistical difference between the treatments for AP, BD, WA, KIC and EF values, and the treatment with the metakaolin showed the lowest values for BD and the highest values for AP, WA and FE. The treatment with ground carbonate and residual pulping showed intermediate results when compared to the other treatments. No statistical differences were found between the fiber-cement treatments for MOR values.

Effect of Association of Sugarcane Bagasse with Eucalyptus Wood on the Quality of Particleboard

Particleboard industries, which are progressively increasing in number, consume a significant amount of wood from planted forests, mainly from the Pinus and Eucalyptus genera. However, these panels can be produced from any lignocellulosic material that provides high mechanical strength and good physical characteristics. Accordingly, the waste generated by the Brazilian agribusiness industry is an alternative resource for manufacturing particleboards. The study aimed to evaluate the effect of the combination of sugarcane bagasse and eucalyptus wood on the physical and mechanical properties of particleboards. The panels were produced with sugarcane bagasse in the proportion of 0, 25, 50, 75, and 100% supplemented with E. urophylla. The panels were produced with 9% urea-formaldehyde adhesive, nominal density of 0.70 g/cm3, and with the pressing cycle of 160°C temperature, specific pressure of 3.92 MPa, and operation time of 8 min. The significance of the proportion of sugarcane bagasse on all physical and mechanical properties was evaluated. The panels with the combination of wood with sugarcane bagasse showed the lowest values in the physical properties and the highest values in the mechanical properties. Only panels prepared with 25% and 50% sugarcane bagasse met all the requirements of the marketing standards.