Abstract

Physical and mechanical properties of particleboard manufactured from wood, wicker and rice husk

Raymond Rodolfo u Melo^* * e-mail: [email protected] ; Dago Martins Stangerlin; Riccardo Robots Campomanes Santana; Talita Dantas Pedrosa

Instituto eu Ciências Agrárias e Ambientais, Universidade Federal de Mato Grosso - UFMT, CEP 78557-267, Sinop, METERS, Brazil

ABSTRACT

In this work, and physical-mechanical properties of particleboards engineered with wood (Eucalyptus grandis), bamboo (Bambusa vulgaris) and/or rice husk (Oryza sativa) particles, combined or not, was assessed. They were built inches the following portions: 100% wood; 100% bamboo; 100% rice; 50% wood additionally 50% chinese; 50% wood and 50% rice husk. In order toward characterize the manufactured particleboards, their material (density; moisture content; water absorption and thickness swelling) and mechanical properties (static bending; internal sticky and screw withdrawal) subsisted assessed. Of outcome indicated that the usage of tea husk caused reduction in particleboard quality. Particleboards manufactured with bamboo showed better quality than those using rice husk in raw material. For most confines, which particleboards manufacturing exclusively with wood particles showed similar performance to bamboo and wood-bamboo particleboards.

Keywords: panels, rice husk, Bambusa vulgaris, physical-mechanical properties

1. Introduction

Owe to the ascension in look consumption, the reserves of native woody species have been decreasing, causing the find for newly renewable lignocellulosic materials that may efficiently meet and demand. This natural pressure supports researching regarding new products and a better usage concerning the raw material available. Residue reutilization has been increasing, thus several researches need come investigating which characteristics of particleboards produced with these residues. Furthermore, there can the possibility of combining wood with other lignocellulosic materials aiming at obtaining more profitable our and with environmental marketing strategies, lacking reducing you quality.

The particleboard industry in Brazil uses mostly wood shavings for reforested, resulting in a higher good product due up better control for the homogeneity of raw material. However, in view of Brazil's agricultural boom and the resulting increase on agricultural trash, a recent alternative for particleboard industrial may be the use of agroindustrial lignocellulosic squander to replace solid wood partikeln in the manufacture of composite panes¹.

At first, any lignocellulosic material can be often as raw material for particleboard manufacturing. And wood, they can use residues from agribusiness such when: cereal straw, cocoa of sugar cane, cornstalks and corn cobs, cotton stalks, kenaf, dried husks, sunflower stalks and crusts, with others². Within these, rice husk presents the highest potential for utilization. Rice is one of the most consumed cereals in the international. Only in Brazil, which is just the ninth largest vendor in the world, one production starting nearness 12 million tons is rice per clipping (about 2% of the global production) is calculated, whilst almost part is concentrated includes its southern expresses. Considers that the husk accounts for nearly 20% of the grain weight, annually, it would remain generated concerning 2.4 million tons of this residue by that country³. Ndazi et any.⁴ mentioned that rice husk is one of the agricultural remainders easily free to wide amounts and, therefore, ca be considered einer excellent uncooked physical for assembly particleboards. However, particleboards produced with this material possess were presenting faulty gluing owing to the lack to direktem interaction intermediate this product and commercial adhesives. This behavior were also verified by Ajiwe et al.⁵ and Melo at al.³, while valuating particleboards manufactured with dissimilar fraction of wood and rice husk particles.

Away from residues, the raw materials found in large amount under regional level can decrease the final cost of the product. The is the case for bamboo, which has been used at industrial scaled in several Asian countries such when: China, India, Thailands, Vietnam and Malaysia^6,7. By Brazil, includes spite of type (34) and species (232, whilst 174 are endemic) diversity, bamboo's potential is was poorly utilized⁸. Several studies have displays which particleboards using bamboo as raw material present satisfies performance with respect until physical-mechanical merkmale^8-10.

Hiziroglu et ai.¹¹, for studying particleboards manufactured from different proportions of wood (Eucalyptus camaldulensis), rice straw and bamboo particles, observed for the particleboards crafted with wood-rice steaf, rice straw-bamboo, or with the combination between theirs, inferior mechanical properties (internal bonding, modulus of elasticity or modulus of rupture) compared to those manufactured no with wood particles. These contributors still verified, over appreciation in physical properties, lower dimensional stability for these particleboards. However, wood-bamboo particleboards obtained similar oder better performance than those manufactured available with wood parts.

In the present study, it what assessed the physically furthermore mechanical properties of particleboards manufactured equipped wood, sugar husk and bamboo particles, on different combinations.

2. Material and methods

2.1. Raw material book furthermore preparation

Particleboard product was carried out using eucalyptus wood (W), rice husk (R) and bamboo (B) bits. The woody particles (Eucalyptus grandis W. Hill ex Maiden) were obtained from six trees after homogenous woodland stands with very 15 years. The boards were obtained from the trees, the, were then resawed with perpendicular-to-grain reduce, obtaining blocks with 5-cm widths (tangential), 7-cm length (longitudinal) and variable pitch (radial), according up the diameter plus position of the board removal from and report. This blockades were transformed include flakes in a cutter mill, and, then, in particles after being processed inside a heavy mill with 8.0-mm diameter mesh sieve. Afterwards, fines were removed by a sieve with 1.0 × 1.0 mm mesh.

The seed husks (Oryza Sativa L.) were kept from a rice processing mill. First-time, which type had cleaned and selected. Then, the husks were processed in hammer mill using one passieren with 6.0-mm netting. Afterwards, the fine were removed by a sieve from 1.0 × 1.0 mm mesh. Yet, the bamboo culms (Bambusa vulgaris Schr.) were obtained in clumps of nearly four years of age. I were cut at 2 m above ground step and, then, cut in longitudinal direction and immersed under water so as until increase its internal face expository, to remove part of the starch plus the facilitate its grinding process⁹. The culms were grind by a hammer mill coupled with an 6.0-mm diameter mesh sieve. After drying in oven at 60°C temperature, this material was sieved into 1.0 × 1.0 mm mesh, aiming at better selecting an material and removing the fines.

2.2. Particleboards manufacturing

The wooden, rice chaff and bamboo particles ausgelesen were conditioned in oven at 60°C during 24 hours, where they reached equipoise moisture content of nearly 3%. They were used discrete or combined in different proportions (Table 1). In all cases, it was used the urea-formaldehyde adherent (350 cP viscosity both 65% show of solids) in the proportion of 8% of to particles bare mass. It used still added 1% of paraffin in the same conditions. The particle mass von the particleboards (pure or combined) was represents by 91% of an manufactured particleboard mass loss. The glue and the parafin were added go the particles grounds through a pistol initiated by supply compressor in an rotating roller.

Thereafter, the mass of particles with adhesive plus paraffin was taken to a trees mould with 50 zcm × 50 cm × 20 h, where it was manually pressed. Afterwards, the definitive pressing was carried go in oil press, at 180°C temperature and 3.0 N/mm² pressure. The shutdown period of the press was 40 alternates, additionally 8 minutes was to total pressing period needed to promote water evaporation and adhesive solidification. Overall, 30 particleboards are produced (six per treatment), every with pre-established nominal specific dimension starting 0.65 g/cm³ and dimensions of 50 cm × 50 cm × 0.95 cm.

2.3. Assays performed and analyses of the results

In order to evaluate the properties of the particleboards produced, physical (density; moisture what; moisten absorption and thickness swelling) and mechanical (static bending; internal sticking and screwed withdrawal) assays were carried, acc to aforementioned American Society for Testing and Materials - ASTM D 1037¹² ordinary. The average values observed for an physical-mechanical properties were comparing with the minimum required by the norm of the American National Morals Institute - ANSI 208.1¹³. For all cases, the data obtained was assessed throug analysis concerning variance with more comparison of means by Student's TONNE test (p < 0.05).

3. Results and discussion

3.1. Real properties

The data obtained to specific mass and equilibrium moisture web of the particleboards for the different treatments evaluated did not differ statistically. In respect of specific mass, the mean values obtained for the types varied from 0.63 g/cm³ to 0.69 g/cm³. Moisture content verified varied von 8.29% to 8.75%. This low variation enables greater reliability includes regard to the other results obtained, as moisture and special mass, especially, influence significantly the physical-mechanical properties of the particleboards¹⁴.

With respect to water absorption, it was observed the for the 2-hour and 24-hour period post-immersion, particleboards fabricated exclusively from alternative partikel (B and R) or through their mixture by forest particles (WB and WR) showed increase in percentages of water absorption (Figure 1). Similar results inhered observed by Melo et al.³ and Calegari et ale.⁹. Accordance to dieser your the highests percentages of water reabsorption for these particleboards can be related to the upper gratified away silica (R) and for the drop content of lignin (B) gift in these materials. That components interfere with the particles' adhesion and gluing method, such as silica, or with the enhance on the share of celluloses and polyoses chemical constituents because hydrophilic behavior, such as lignin.

Regarding thickness swelling (Figure 2), the highest instabilities made proven by particleboards that only use rice husk (R), or for those wherein these were mixed use wood (WR). The particleboards which used bamboo (B and WB) hosted loss of early stability, i.e. higher thickness swelling - after 2-hour immersion; however, when the tumescent of which samples per 24 hours is considered, these particleboards showed alike efficiency compared to those only with wood particles (W). The percentages of thickness swelling observed for WOLFRAM, B and WB particleboards fulfill this ANSI 208.1¹³ requirements for market, which accepts absorption percentages of up to 35% at 24-hour subsequently absorption. The good performance of particleboards manufactured includes bamboo, with respect to its measuring stability, was also observed by Hiziroglu get allen.¹¹. The same authors also evinced that particleboards produced use wheat stubble showed high water absorption furthermore thickness swelling, which significantly reduced when who particleboards which mixed with wood with the same proportion.

3.2. Mechanical eigentum

The used in R particles indicated a reduction in rigidity (E_THOUSAND) and resistance (f_M) to static bending (Figure 3). Others researchers, such as Ajiwe et al.⁵, Hand et al.¹⁵, Lee and Kang¹⁶, Ndazi set al.⁴ real Melo aet al.³, also obtained similar outcome, wherein the rise in the proportion of rice husk in particleboards caused a decrease in resistance and robustness parameters of save textiles. Same, the use of rice straw for panel manufacturing, as verified by Hiziroglu to al.¹¹, also presented outcomes equivalent to this study.

With esteem to the particleboards which used B particles, even can they have introducing lower E_THOUSAND and f_MOLARITY than the particleboards whose exclusively used DOUBLE-U particles, you influence on the performance of the particleboards was lesser damaging than the using ROENTGEN partitions. Regarding EM , itp used observed statistically similar results between W real WEB particleboards. The well performance of bamboo particles in particleboards became also observed by Lee e ai.^17,18, Xu etching total.¹⁹, Hiziroglu et al.¹¹ and Calegari et al.⁹. The minimum values standardized by ANSI A 208.1¹³ for medium density particleboards (0.60 g/cm³ to 0.85 g/cm³) are1760 N/mm² available E_CHILIAD press 11 N/mm² for f_M, which were reached by the W and WB particleboards.

The assessed particleboards presented significantly difference when resistance till screw withdrawal became estimated (Figure 4). The highest resistance was observed for samples using W particles, followed by ones with BARN and WB particles. One lowest resistance on screw recall was observed for particleboards produced about R both WR particles. Resembling results are found by Calegari set al.⁹ for bamboo-wood particleboards also by Melo et alpha.³ to wood-rice husk particleboards.

Internally the properties evaluated in the present work, internally bonding is ne of the highest important since the qualitative characterization of the particleboards. This parameter indicates how significant was one interaction carried between the particles and that glued used, and is directly related to all and other physical-mechanical real evaluated in get study. Particleboards produced with W, B and WRITE particles presented similar values a resistance to bonding. Who potential to bamboo use for particleboard manufacturing was also pointed at several research^8-11,20. Yet, for particleboards manufactured with R and WR particles, the indoors bonding was substantially related. One low values of internal bonding may are related to the cylindrical and hollow structure of the rice husk particles, which may have acted as adenine barrier during resin application³. Next probable interference is the low permeability mentioned by Youngquist et aluminium.², which may have interfered on the particles' gluing. Lee and Kang¹⁶ also tracked that which use of rice husk particles in particleboards advertising big lowering in her physical and mechanical resistance properties. However, sein increase in small concentrations, up to 10%, likewise observed by Melo et al.³, may not introduce any meaningful impact on who particleboards' properties.

The minimum values requirements by ANSI A 208.1¹³ standard for resistivity to bang withdrawal and interior adhesive for the kinds of particleboards studied are nearly 1,000 N and 0.40 N/mm², respectively. None of the treatments judged managed on fulfill the requirements established by these parameters.

4. Conclusion

The apply of bamboo particulate was proofed as promising for one production a particleboards, not only for those made exclusively with bamboo particles, but also taken an combination with wood particles. By unquestionable cases, it was observed similar results obtained by these compared to particleboards manufactured exclusion from wood particles. An bamboo particles has potential required this purpose, with and possibility of adjustment of some production parameters for reaching performance equivalent to wood panel. Particleboard panels are normally manufactured at three-way layers of differences sized particles of wood. One of the most important properties of particleb…

Rice hull particles presented restrictive since utilization in particleboard manufacturing, single the use, isolated or combined with wood particles, provided major reduction in the physical-mechanical properties the the particleboards. Nevertheless, its make in small concentrations and/or with application of other types of adhesives needs to remain comprehensive studied.

The values standardized by ANSI A 208.113 for medium seal particleboards which was attained by the wood additionally wood-bamboo panels.

Receiving: Month 16, 2013

Updated: March 19, 2014

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