Bárbara Maria Ribeiro Guimarães

Chemical treatment of banana tree pseudostem particles aiming the production of particleboards

Brazil is one of the major banana producers in the world, and consequently generates a great amount of residues from this crop, which could be utilized in particleboard production. The present work aimed to evaluate the effect of different chemical treatments of the particles of Musa sp. pseudostem, on their chemical and physical properties (basic density), and on the physical and mechanical properties of the particleboards produced with the same material. Five treatments were applied to the particles: 1) without treatment (control); 2) 2% acetic acid; 3) 0.5% NaOH; 4) acetone (1/1 in volume/volume); and 5) water. Panels with medium density were produced (0.70 g/cm3), bonded with 12% (in relation to the particle mass) of urea-formaldehyde adhesive. The pressing cycle was conducted at 160o C, under 4 MPa, during 8 min. The results obtained indicated that the chemical treatments performed in the particles of banana tree pseudostem affected their chemical composition. The basic density of the particles was 0.10 g/cm3, and only the NaOH treatment led to its increase for values around 0.13 g/cm3. The panels produced with particles without treatment (control) and particles treated with acetic acid presented the lowest values of water absorption and thickness swelling after 2 and 24 h of immersion. Mechanical properties of all the panels produced were below the minimum recommended by the standard CS 236-66 (COMMERCIAL STANDARD - CS, 1968).

NaOH Treatment Impact in the Dimensional Stability of Banana Pseudostem Particleboard Panels

This work intends to verify the technical feasibility of NaOH treatment in particleboard manufacture made from banana pseudostem fibers. The particles were treated for a 24 hour period and subsequently washed with water to remove the product. The concentration used was NaOH at 0.5%. The adhesive used was urea - formaldehyde at 12%, the pressing cycle was 4 MPa, at 160 °C for 8 minutes. The water absorption after 2 hours immersion was 148.79% and 189.83% after 24 hours. Thickness swelling value after 2 hours was 54.96% and 74.05% after 24 hours. The results were above the literature values and the minimum values required by the CS 236-66 standard for swelling after 24 hours immersion.

SELECTION OF CLONES OF Eucalyptus urophylla FOR PLYWOOD PRODUCTION

This work aimed at the evaluation of six (6) Eucalyptus urophylla clones of Companhia Mineira Metais - Unidade Agroflorestal (VM-AGRO) for making particleboard panels. Six (6) panels to each clone studies were produced. About 320g/m² of Phenol phormol aldehyde adhesives Were utilized. The pressing cycle parameters were: pressure of 1.47MPa, temperature of 150oC and 10 minutes of pressing time. It was concluded that clones of Eucalyptus urophylla show a great potential for production of particleboard panels, since they presented values of physical and mechanical properties above the ones referenced in literature and highly superior to those required by the ABNT Standards 31:000.05-00/2 (static bending) and EN 314-2 (shearing resistance), the tested clones can be used for producing concrete mold (FOR). The clone which stood out the most in all the properties tested was the clone 36.This work aimed at the evaluation of six (6) Eucalyptus urophylla clones of Companhia Mineira Metais - Unidade Agroflorestal (VM-AGRO) for making particleboard panels. Six (6) panels to each clone studies were produced. About 320g/m² of Phenol phormol aldehyde adhesives Were utilized. The pressing cycle parameters were: pressure of 1.47MPa, temperature of 150oC and 10 minutes of pressing time. It was concluded that clones of Eucalyptus urophylla show a great potential for production of particleboard panels, since they presented values of physical and mechanical properties above the ones referenced in literature and highly superior to those required by the ABNT Standards 31:000.05-00/2 (static bending) and EN 314-2 (shearing resistance), the tested clones can be used for producing concrete mold (FOR). The clone which stood out the most in all the properties tested was the clone 36.

Evaluation of Physical Properties of Particleboard Produced from Sugarcane Leaves

The southwest region of the state of Goiás stands out for agriculture, especially the production of grain and sugarcane. This high agricultural production has a result of generation of agroindustrial waste and it has a high potential to be exploited for particleboard manufacturing. In this context, the objective of this study was to evaluate the use of sugarcane leaves in the production of particleboards, compared to eucalyptus panels, through the evaluation of their physical properties. Three panels were made with 100% sugarcane leaves, and three with eucalyptus wood were produced. They were produced with a nominal density of 0.60 g/cm3. 12% urea-formaldehyde adhesives were applied based on their resin solid content. The used pressing cycle was: pressure of 4.00 MPa, temperature of 180°C and time of 15 minutes. After production, the same properties were evaluated on their water absorption and thickness swelling after 2 and 24 hours of immersion. A randomized design was used, and the averages were compared by the Scott-Knott test at 5% significance. Based on these results, it can be seen that panels produced with sugarcane leaves exhibited higher values for physical properties than eucalyptus panels.Keywords: Thickness swelling, waste ,water absorption.

Dimensional Stability of Particleboards Produced with Soybean Residue

The southwest region of Goiás is a major grain producer in the country, with emphasis on soybeans. It is protected by a pellicle grain into a legume. After its separation, the film is eventually discarded or used as animal feed. One alternative is the production of particleboards, considering lignocellulosic material, which could add value to this raw material. In this sense, the objective of this study was to evaluate the dimensional stability of particleboards produced with soybean residue, comparing them with eucalyptus panels. The particleboard was made with a nominal density of 0.55 g/cm3, and 12% of urea-formaldehyde adhesive were used, based on their content of resin solids and pressing cycle of 3.92 MPa, 180oC for 15 minutes. Three panels were produced by treating. The assessment of dimensional stability was made by measuring their density, water absorption and thickness swelling after immersion for 2 and 24 hours. Based on the results, it can be seen that, statistically, the panels had equal densities, an average value of 0.52 g/cm3. It is noted that the panels produced with a soy film had water absorption values of 2 to 24 hours, and thickness swelling in 24 hours, in comparison with the upper eucalyptus. For thickness swelling after 2 hours, no statistically significant difference between the tested materials was observed.

Feasibility of Using MDP Panels, Compared to Conventional Particleboards

The objective of this study was to investigate, by physical properties, the efficiency of MDP panels, compared to conventional particleboards, since MDP was considered as a raw material for the manufacture of these panels. MDP panels had the following composition: 20/60/20 face/core; a urea-formaldehyde adhesive was used, with a solids content of 55%; pH 8.42; viscosity of 420 Cp and gel time of 51 seconds. 12% of dry base resin were applied to the particles. The pressing cycle was 4 MPa, with a temperature of 160°C for a period of 8 minutes. The panels were produced with a density of 0.70g/cm3. We observed that with the exception of the physical properties of water absorption after 2 hours, the MDP showed lower physical properties (water absorption after 24 hours and thickness swelling after 2 hours and 24 hours of immersion in water) in relation to the panels conventional clusters. Thus demonstrating its superiority in relation to the physical properties of MDP compared to conventional agglomerated panels, emphasizing their use in this way.

Physical Properties of MDP Panels Produced with Different Proportions of Wood and Pseudostem

The objective of the present study was to verify the technical feasibility of using banana pseudostem fibers in the manufacture of MDP in intermediate panel layers, in different associations with wood from eucalyptus and banana pseudostem. The physical properties of water absorption and thickness swelling for immersion in water for both 2 and 24 hours were evaluated. Three panels were produced according to American Standard ASTM D 1037. 12% urea-formaldehyde adhesive were used for the production of panels. The pressing cycle was 4 MPa, with a temperature of 160°C for a period of 8 minutes. The panels were produced with a density of 0.70g/cm3 and had the following composition: 20/60/20 face/core, in which the face consisted of eucalyptus and varying proportions of pseudostem in the core (10%, 20% and 30%) and in eucalyptus. It is observed that the panels with 20% particles in the core showed the best results, compared to other panels evaluated.