Impregnation of Bamboo (Gigantochloa Scortechinii) with Phenolic Resin for the Production of Dimensionally Stable Plybamboo

Low molecular weight phenol formaldehyde (LMwPF) resin was used to enhance the dimensional stability of bamboo strips (Gigantochloa scortechinii). Resin was impregnated into bamboo strips via vacuum process before the strips were converted into plybamboo. The present study was undertaken to develop a process to produce high dimensionally stable plybamboo. The work included evaluation of resin impregnation process, establishment of suitable drying/curing technique and final pressing of phenolic-treated bamboo strips. Evaluation of bonding properties, dimensional stability and mechanical properties of phenolic-treated plybamboo were also conducted. The bamboo strips were taken from basal and middle portions of bamboo culm. To treat the bamboo strips with LMwPF resin, firstly, a vacuum period of 1 hour was applied before the strips were soaked in resin for at least 90 minutes. The samples were later dried in an oven at 60°C for 9 hours. The mean weight percent gain (WPG) and moisture content (MC) of dried phenolic-treated bamboo strips were 14.5% and 7%, respectively. Drying the phenolic-treated bamboo strips for > 9 hours resulted in cupping of the strips. Phenolic-treated strips were then hot pressed for 5, 8, 11, 14 and 17 minutes at 14 kgm-2 and 140°C. Water absorption (WA), thickness swelling (TS) and linear expansion (LE) of the strips decreased when the curing time was extended from 5 minutes to 17 minutes but antishrink efficiency (ASE) increased. The mean value of modulus of rupture (MOR) for untreated strips (177 Nmm-2) was significantly lower than the phenolic-treated strips (224 Nmm-2) after 17 minutes pressing time. However, no significant difference was observed in modulus of elasticity (MOE) and compression parallel to grain. Results showed that the optimum pressing time for phenolic-treated strips was 11 minutes. This work also established an optimum pressing time to produce high dimensionally stable plybamboo. For this, phenolic-treated bamboo strips were glued together edge-to-edge using phenol resorcinol formaldehyde (PRF) resin to produce a veneer. The veneers were then assembled perpendicular to each other to form a 3-ply (12 mm) and 5-ply (20 mm) plybamboo using phenol formaldehyde resin as a binder. The plybamboos were hot pressed at an optimum pressing condition of 140oC (pressure 14 kgm-2) for 22 (3-ply) and 33 (5-ply) minutes. The bonding strength of the plybamboo obtained in this study met the minimum requirement of MS 228-1991. WA, TS, and LE of phenolictreated plybamboo were significantly lower compared to those of untreated plybamboo. The MOR, MOE and compression parallel to grain of the phenolic-treated plybamboo were significantly higher compared to those of untreated plybamboo. For 3-ply, the values were 164 and 127 Nmm-2 for MOR, and 19767 and 16778 Nmm-2 for MOE, and 60 and 41 Nmm-2 for compression parallel to grain, respectively. Similarly, for 5-ply phenolic-treated plybamboo the MOR, MOE and compression parallel to grain of were 38%, 30% and 33% respectively higher than those of untreated plybamboo. Generally, the treatment of bamboo strips with LMwPF resins were found to significantly improve the properties of plybamboo made from them

Evaluation of wetting, structural and thermal properties of electrospun nanofibers at different pineapple leaf fiber / polyethylene terephthalate ratios

In this study, pineapple leaf fiber and polyethylene terephthalate electrospun nanofibers were produced via electrospinning process. Six ratios of pineapple leaf fiber/polyethylene terephthalate, namely 1/10; 1/7,5; 1/5; 1/1 and 1,3/1 were prepared and their wetting, structural and thermal properties were characterised. Wetting properties of this sample were studied using contact angle measurement. X-Ray Diffraction, differential scanning calorimetry and thermogravimetric analysis  were conducted to get better understanding on the structural and its thermal properties respectively. The results revealed that increasing the pineapple leaf fiber content simultaneously increased the ability of nanofibers to adsorb water as shown by lower contact angle degree with 81,6° and adsorption time of 15 seconds. An increase in pineapple leaf fiber ratio did not change the peak position in X-Ray Diffraction and no new peaks observed for any sample. However, the peak at 23° for samples with ratio 1/1 and ratio 1,3/1 exhibited higher intensity compared to that of pure polyethylene terephthalate. Thermal properties obtained from thermogravimetric analysis results suggested that thermal properties were not influenced by the pineapple leaf fiber ratio. Overall, pineapple leaf fiber/polyethylene terephthalate electrospun nanofibers produced at the ratio of 1/1 displayed the optimum performance

Adhesion and bonding characteristics of preservative-treated bamboo (Gigantochloa scortechinii) laminates.

This study were investigate the adhesion and bonding characteristics of bamboo (Gigantochloa scortechinii) strips and laminates treated with permethrin-based preservative (Light Organic Solvent-Based (LOSP) and Water-Based (WBP)) formulations, Tributyl Tin Oxide (TBTO) and borax. The bomboo culm were cut into strips and treated with those selected chemicals. The bamboo strips were then glued edge to edge to form a bamboo veneers before fabrication of the three ply perpendicular bamboo laminates. In this research the properties studied include wettability, buffering capacity, shear strength and wood failure. Untreated strips and bamboo strips which were boiled in water (100°C) were also tested for comparison purposes. Those strips treated with LOSP had higher contact angle (3°-9°) which reflects that the surface of the treated strips is less readily wetted. Whereas, borax-treated strips had the highest wetting rate where the value is 1°. In buffering capacity study shows that treated bamboo was more stable towards alkali. This is suggested that a buffering agent (Calcium carbonate) is required in the adhesive formulation to ensure sufficient curing of the resin. Preservative treatments on bamboo strips significantly affect shear strength and wood failure of the laminates. Shear and wood failure of the laminated bamboo were significantly reduced especially in the wet condition where, the range is 0 N mm-2 (WBP treated) to 0.65 N mm-2 (boiled-treated) when compared to untreated bamboo laminates (0.79 N mm-2). While, in dry condition test, the glue bond strength of were range from 0.64 N mm-2 (WBP-treated) to 2.04 N mm-2 (borax-treated). All chemicals and non-chemical treatment generally affects the glue strength of the bamboo laminates especially in wet condition test. In dry condition test there are slightly reductions in glue bond strength but the quality still meets the requirement in the British Standard Part 8: Specification for Bond Performance of Veneer Plywood

Properties of medium-density fibreboard (MDF) made from treated empty fruit bunch of oil palm

The objective of this study was to evaluate the physical and mechanical properties of experimental medium density fibreboard (MDF) panels manufactured from empty fruit bunch (EFB) of oil palm (Elaeis guineensis). Panels were made from EFB treated with boiling water, soaked in sodium hydroxide (NaOH) or their combination by using phenol formaldehyde at 8, 10 and 12% based on oven-dry weight of fibre. Mechanical and physical properties including modulus of elasticity (MOE), modulus of rupture (MOR), internal bond strength, thickness swelling and water absorption of the samples were determined according to the Malaysian Standards (MS 1787: 2005). Based on results of this work, it seems that EFB can be used as raw material to manufacture value-added MDF with accepteble properties based on the standards. Panels made from fibres treated with NaOH in 12% resin produced the highest MOR (31.4 MPa). Fibres treated with the combination of NaOH and boiling water resulted in panels with reduced bending properties. All types of treatments enhanced dimensional stability of panels. All treated EFB fibres were less sensitive when exposed to alkaline condition compared with acidic condition

Impregnation and drying process of bamboo strips treated with low molecular weight phenol formaldehyde (LMwPF) resin

Impregnation and drying process of phenolic treated bamboo strips with low molecular weight phenol formaldehyde (LMwPF) resin. A study was under taken to determine an impregnation process and suitable drying duration for phenolic treated bamboo strip at basal and middle portions of Gigantochloa scortechinii. The strips were impregnated using vacuum process. After treated with low molecular weight phenol formaldehyde resin (LMwPF) using different duration of soaking, the weight percent gain (WPG) of bamboo strips was measured. The weight percent gain (WPG) of the impregnated G. scortechinii (basal and middle portions) increases when longer soaking time. After 150 minutes of soaking, the WPG were 14% and 15% for basal and middle portions, respectively. The specimens were then dried in an oven for 3 to 12 hours at 60°C. The reduction of moisture content (Mc) was plotted in a graph and analyzed. The suitable drying duration for bamboo strips were found to be between 6 to 9 hours. A significant difference (p<0.05) WPG was observed at middle portion but not within the basal portion. Moisture content of bamboo strips reduced with drying duration from average of 20% to 5%. However, the optimum drying duration should not exceed 9 hours after which the samples start to cupping

Enhancing the Properties of Mahang (Macaranga spp.) Wood through Acrylic Treatment in Combination with Crosslinker

Macaranga spp. (mahang) was treated with methyl methacrylate (MMA) in combination with a crosslinker trimethylolpropane trimethacrylate (TMPTMA). Polymerisation was carried out by catalyst heat treatment. A fairly consistent acrylic retention was found in the wood when treated with or without crosslinker. Polymerisation of MMA is at maximum with 1% crosslinker and beyond this concentration the polymerisation decreased. The dimensional stability in terms of anti-swelling efficiency (ASE) was determined and found to be improved on treatment. Water absorption was also found to be decreased considerably for treated wood. Mechanical strength of the treated wood in terms of modulus of rupture (MOR), compressive stress and hardness were improved, but the stiffness (modulus of elasticity) did not change. In terms of specific strength (strength to density ratio), the treated material is less stiffer and less strength in lateral direction compared to untreated wood. However, the specific compressive strength perpendicular to the grain and hardness of the treated material were superior compared with the untreated

Mechanical Properties and Failure Behaviour of Gigantochloa Scortechinii

The physical and mechanical properties of bamboo have been widely studied but information of these properties at the nodes is still lacking. The presence of node in a bamboo split may affect the mechanical strength of the material. To enable usage of bamboo in a longer length, understanding the mechanical properties and behaviour of the bamboo at the node is crucial. This study used 4-year-old Gigantochloa scortechinii bamboo. The physical and mechanical properties at the nodal and internodal sections of the bamboo split were tested in green and air dry conditions. The orientations of the bamboo splits with the periphery of the bamboo split oriented facing downwards (referred to as compression) and facing upwards (referred to as tension) were taken into consideration during the mechanical test. Results suggested avoiding orientating the bamboo splits with the peripheral skin positioned at the bottom as it reduced the mechanical properties. The failure behaviour of bamboo splits at the node and internode were evaluated and compared

Tensile properties of untreated bambusa vulgaris, gigantoch- loa levis gigantochloa scortechinii, gigantochloa wrayi, and schizostachyum zollingeri bamboo fibers

In the last couple decades, bamboo is getting interest due to the usefulness in textile application beside the most sustainable plant in earth. Textile fiber requires physically long, featherweight, and fine in diameter. Bamboo fibers impose high cellulose and lignin content. In a single fiber form, bamboo has very short physical length which lesser than 4 mm. This natural characteristic could affect the mechanical properties in fiber bundle or long fiber formation for textile processing. Besides, the extraction of long and fine bamboo fibers is significantly challenging over different species of them. Therefore, the tensile behavior of the untreated bamboo fibers over variety species shall be understanding in-depth. This study is about identifying tensile properties of bamboo fiber bundle of five commercialized bamboo species in Malaysia. Three regions of fiber bundles locations were extracted mechanically and tested. The long bamboo fiber tenacity and fineness were examined besides tensile strength and strain to failure value. Among those species, G. levis species demonstrated the highest tensile strength around 98MPa with strain to failure at 4.51%. G. wrayi (BT) recorded the coarsest fiber at 231 tex while the highest tenacity was obtained by B. vulgaris (MYK) at 10.88 cN/tex

The potential of utilising bamboo culm (Gigantochloa scortechinii) in the production of structural plywood

The potential of utilising 4-year-old Gigantochloa scortechinii culms for structural plywood was evaluated based on their gluing, physical and mechanical properties. Bamboo strips (without epidermis) were glued together edge to edge using polyvinyl acetate to produce a ply of 400 mm x 400 mm x 4 mm. The plies were assembled perpendicularly to each other to form a bamboo plywood of three plies. Phenol formaldehyde was used as a binder. The assembly time of the adhesive was 30 min. The hot press temperature and pressure were 140°C and 1.4 N/mm2, respectively, and they were maintained for 6.5 min. A commercial structural grade 5-ply plywood (Hopea sp.) with the same thickness of the bamboo plywood (12 mm) was used for comparison purposes. The bonding strength of bamboo plywood meets the minimum standard requirement of the Malaysian Standard. The modulus of rupture (MOR), modulus of elasticity (MOE) and compression parallel to grain of the bamboo plywood were significantly higher compared to commercial plywood. The values were 65.4 vs. 42.0 N/mm 2 for MOR and 8955 vs. 4583 N/mm2 for MOE and 35.39 vs. 19.93 N/mm2 (compression parallel to grain). The width expansion and thickness swelling of bamboo plywood (after soaking in water 24 h) were markedly higher than commercial plywood, i.e. 1.51 vs. 0.43% and 5.44 vs. 4.42%, respectively

Mechanical properties of 10-year-old sentang (Azadirachta excelsa) grown from vegetative propagation

Mechanical properties of 10-year-old sentang (Azadirachta excelsa) grown from vegetative propagation. This paper reports the mechanical properties of sentang (Azadirachta excelsa) wood cut from trees that were planted by vegetative propagation, their variations along tree height and also between sapwood and heartwood. The correlation between selected anatomical properties as well as density and mechanical properties were also presented. There was no significant difference in modulus of rupture between wood from seedling and rooted- cutting trees. However, wood from rooted-cutting trees showed higher modulus of elasticity compared with wood from seedling trees. On the other hand, compression and shear parallel to the grain were significantly higher in wood planted from seedling compared with wood from rooted-cutting trees. There was an increase in mechanical properties at the bottom portion towards the top irrespective of the planting technique. Mechanical properties were higher in heartwood than in sapwood. Mechanical properties were correlated with anatomical properties rather than density. Rooted cutting could be a promising method for planting sentang, apart from seedling