Ivaldo De Domenico Valarelli

Prospects for the use of municipal tree pruning wastes in particleboard production.

The purpose of this study was to evaluate the physical and mechanical properties of particleboard made   with pruning wastes from Ipê (Tabebuia serratifolia) and Chapéu-de-Sol (Terminalia catappa) trees. Particleboards were prepared with both wood species, using all the material produced by grinding the pruning wastes. The particleboards had dimensions of 45×45 cm, a thickness of approximately 11.5 mm and an average density of 664 kg/m3. A urea–formaldehyde adhesive was used in the proportion of 12% of the dry particle mass. The particleboards were pressed at a temperature of 130°C for 10 mins. The physical and mechanical properties analyzed were density, moisture content, thickness swelling, percentage of lignin and cellulose, modulus of resilience, modulus of elasticity and tensile strength parallel to the grain, accordingly to the standards NBR 14810 and CS 236-66 (1968). The particleboards were considered to be of medium density. The particle size significantly affected the static bending strength and tensile strength parallel to the grain. Ipê presented better results, demonstrating a potential for the production and use of particleboard made from this species.

Physical and mechanical characterization of a recycled polypropylene and wood flour without additives

Univ Estadual Paulista Julio de Mesquita Filho UN, FEB, Programa Posgrad Engn Prod, Sao Paulo, Brazil

Effects of belt speed, pressure and grit size on the sanding of Pinus elliottii wood

The present paper aims to evaluate the influence of the factors (belt speed, pressure and grit size) on the output parameters (temperature and surface roughness) for Pinus elliottii wood sanding, processed parallel to the fibers. Three levels of belt speed, three levels of pressure and four levels of grit size were employed, with six replicates for each process, totaling 216 observations. The experiment conducted under a randomized complete block design (RCBD). The results were analyzed employing the analysis of variance (ANOVA) with 5% of significance level. Only grit sizes were significant to different temperature levels. The same outcome was observed for roughness, where only grits sizes were significant. No interaction between the pressure and belt speed factors were observed for all the results analyzed.

Physical and mechanical properties of particleboard bamboo waste bonded with urea formaldehyde and castor oil based adhesive

This study evaluated the physical and mechanical characteristics of particleboards made of bamboo waste from the species Dendrocalamus giganteus bonded with two different types of adhesives: urea-formaldehyde (UF) and a castor oil based adhesive (M). Thus, eight types of particleboards were produced in the proportions of 6%, 8%, 10% and 12% for each adhesive. The results showed that particleboards produced with UF and M adhesives had acceptable behavior for physical tests according to the Brazilian standard NBR 14810. The results attained in mechanical tests (MOR and MOE), for all particleboards, were below the requirements for structural usage. This indicates that the residue of bamboo is a feasible raw material alternative for particleboards produced for non structural purposes, such as liners, partitions and other uses for internal seal. Regarding the adhesives, the particleboards produced with UF particleboards showed superior results for both physical and mechanical characteristics, when compared to M particleboards with the same percentage of adhesive.

Effects of Macro and Microstructure of Aluminum Alloy AA 6063-T6 with TIG-AC Welding Process with Unbalanced Rectangular Wave

The use of the rectangular wave in the TIG-CA welding process for aluminum alloys allows numerous possibilities of frequency control, wave amplitude variation and positive or negative current for the same wave cycle. The configuration selected is decisive for the effect and final property of the weld bead, where alternating current variation in aluminum alloy welding is widely used and is intended to promote surface oxide layer cleanliness while promoting penetration of the joint. In the literature it is common to find statements that the cleaning of the oxide layer at the welding time is connected to the positive wave cycle and the penetration is connected to the negative wave cycle time. For the research proposal, TIG-AC welding of the aluminum alloy AA 6063-T6 was performed by simple plate deposition with rectangular wave with variation both in the current and in the time of positive polarity of the electrode in the cycle in the current welding wave 140 A, For balance conditions at 50% of the positive polarity at a waveform time period of 20 ms, followed by wave unbalance to 32.5% and 15% of the positive polarity acting time maintaining a constant frequency of 50 Hz for all settings. The results for the selected settings show that the decrease in the positive wave time decreases the penetration and the width of the weld bead and this may be related to the selection of time and frequency used.

Particleboard with Inclusion Bi-Oriented Polypropylene Applied in Architecture

This paper analyze the potentiality of using the BOPP (bi-oriented polypropylene), a byproduct of automotive battery labeling, in the bamboo particleboard production to be used in architecture projects. On this research, were studied both physical and mechanical properties according to the standards NBR 14810-3/2006 and ANSI A208.1/1999. The particleboards are produced in three traces: 75% bamboo and 25% BOPP, 50% bamboo and 50% BOPP and 100% bamboo. The adhesive used was polyurethane resin with a castor oil base, weighing 12% of the total mass of each panel. The physical properties of water absorption and thickness swelling, in both periods of 2 hours and 24 hours, demonstrated a direct relation with the amount of BOPP and impermeability of particleboards produced. Regarding the mechanical properties of bending and tensile strength, the addition of BOPP had an inverse relation to these properties.

Projeto de Produção e Processo de Pré-fabricação de Componentes de Bambu

The design and production process of the workshop shed made of bamboo presented in this paper is the result of almost two years of cooperation between “Viverde” Farmers Association, “Universidade Estadual Paulista” and “Unisol”. The system consists of rounded aroeira pillars, a roof structure formed by in natura bamboo frames and metal connections. The development of the parts and connections detailing, through the technical drawing of each component, enabled the development of standardized precision fittings aiming at optimizing the execution and saving time, energy and raw material on the assembly line. In this process, the creation and improvement of templates was necessary in order to facilitate the assembly of parts. The component assembly phases were recorded at the Experimental Laboratory for Bamboo and Wood Processing UNESP/FEB. The results showed the good performance of the pre-fabrication process of bamboo components.