Quality Enhancement of Falcataria-Wood through Impregnation

( Ihak Sumardi ),( Atmawi Darwis ),( Sahriyanti Saad ),( Muhammad Navis Rofii ) 한국목재공학회 2020 목재공학 Vol.48 No.5

The purpose of this research is to determine the efficiency of impregnation usingphenol formaldehyde resin to enhance Falcataria wood’s stability and better mechanical properties. Impregnation process was carried out after moisture content stabilized at 12% on samples with a dimension of 20 mm × 20 mm × 300 mm at various concentrations and pressure time. Dimensional stability was evaluated by thickness swelling (TS) and anti-swelling efficiency (ASE) and the young’s modulus was conducted according to BS 573. The mechanical properties and dimensional stability of impregnated wood were evaluated. Dimensional stability and mechanical properties of Falcataria wood were successfully increased after impregnation. PF impregnation can improve the mechanical properties and the density from 0.26 g/cm³ to 0.30 g/cm³ even with only 10% of weight percent grain. Dimensional stability increases with increasing resin concentration and time pressure. The highest increase in mechanical properties was found at a higher concentration of PF. The penetration of PF into the wood’s cell darkens the color of impregnated wood.

Development of Bamboo Zephyr Composite and the Physical and Mechanical Properties

Ihak Sumardi,Eka Mulya ALAMSYAH,Yoyo SUHAYA,Rudi Dungani,Ignasia Maria SULASTININGSIH,Syahdilla Risandra PRAMESTIE 한국목재공학회 2022 목재공학 Vol.50 No.2

The objective of this study is to determine the effect of fiber direction arrangement and layer composition of hybrid bamboo laminate boards on the physical and mechanical properties. The raw material used was tali bamboo (Gigantochloa apus (J.A. & J.H. Schultes) Kurs) rope in the form of flat sheets (zephyr) and falcata veneer (Paraserianthes falcataria (L) Nielsen). Zephyr bamboo was arranged in three layers using water-based isocyanate polymer (WBPI) with a glue spread rate of 300 g/m2. There were variations in the substitution of the core layer with falcata veneers (hybrid) as much as two layers and using a glue spread rate of 170 g/m2. The laminated bamboo board was cold-pressed at a pressure of 22.2 kgf/cm2 for 1 h, and the physical and mechanical properties were evaluated. The results showed that the arrangement of the fiber direction significantly affected the dimensional stability, modulus of rupture, modulus of elasticity, shear strength, and screw withdrawal strength. However, the composition of the layers had no significant effect on the physical and mechanical properties. The bonding quality of bamboo laminate boards with WBPI was considered to be quite good, as shown by the absence of delamination in all test samples. The bamboo hybrid laminate board can be an alternative based on the physical and mechanical properties that can meet laminated board standards.

Drying Efficiency of Betung Bamboo Strips (Dendrocalamus asper) Based on Different Solar Drying Oven Designs

Ihak Sumardi,Anggit Kusuma Dewan DARU,Alfi RUMIDATUL,Rudi Dungani,Yoyo SUHAYA,Neil PRIHANTO,Rudi Hartono 한국목재공학회 2024 목재공학 Vol.52 No.1

Betung bamboo (Dendrocalamus asper) is used as a building and handicraft material in Indonesia; however, bamboo needs to be dried to increase its stability. This study aimed to evaluate the efficiency of drying bamboo using solar energy and different drying oven designs. The betung bamboo pieces were dried using a direct solar dryer (direct drying) and an indirect solar dryer (indirect drying) and then the decrease in levels that occurred based on the relative humidity (RH) and temperature values achieved in the two dryers were compared. The highest average temperature in the direct indirect drying oven compartment was 60.1 ± 13.1℃ with 19.9 ± 16.4% RH and 60.2 ± 11.9℃ with 19.5 ± 15.5% RH, respectively. The drying defect in indirect drying was lower than that in direct drying, and indirect drying had a 61.7% greater average water loss than direct drying with significant difference (95%, analysis of variance) based on water loss/compartment volume parameters. Thus, the solar drying oven can be used to air-dry bamboo (14%) for 7 d from an initial moisture content of 70%–80% in bamboo strips. The results of this research can be used for small-scale bamboo processing industries that have limited use of electrical energy with quite good results.

Effect of Vascular Bundles and Fiber Sheaths in Nodes and Internodes of Gigantochloa apus Bamboo Strips on Tensile Strength

Atmawi Darwis,Anne HADIYANE,Endah SULISTYAWATI,Ihak Sumardi 한국목재공학회 2023 목재공학 Vol.51 No.4

Bamboo culm is in the form of a tube/pipe, composed of internodes which are bounded by a partition/diaphragm (node). Anatomically, bamboo is composed of vascular bundles and parenchyma ground tissue. One of the constituents of vascular bundles is fibers that are grouped to form a fiber sheath. The anatomical structure of the nodes and internodes is thought to influence the strength of bamboo strips, including tensile strength. This study aimed to determine the characteristics of vascular bundles (distribution and fiber percentage) and their effects on the density and tensile strength of Gigantochloa apus bamboo strips with and without nodes. The bamboo culms were divided into three parts (outer, middle, and inner) along the radial direction. The results showed that the distribution of vascular bundles and percentage of fiber sheaths decreased significantly from the outer to the inner layer. This also had a significantly decreased density and tensile strength. Furthermore, the number of vascular bundles (in the transverse plane) was greater in the internodes than in the nodes. Anatomically, the orientation of the vascular bundles at irregular nodes is observed in the radial and tangential planes, where the direction is not only in the axial direction, but also in the radial and tangential directions. This caused the tensile strength of the G. apus bamboo strips to be lower at the nodes than at the internodes.

Effects of Steam Treatment on Physical and Mechanical Properties of Bamboo Oriented Strand Board

Sena Maulana,Imam Busyra,Adesna Fatrawana,Wahyu Hidayat,Rita Kartika Sari,Ihak Sumardi,I Nyoman Jaya Wistara,Seung Hwan Lee,Nam Hun Kim,Fauzi Febrianto 한국목재공학회 2017 목재공학 Vol.45 No.6

The objective of this study was to evaluate the properties of bamboo oriented strand board (B-OSB) from an-dong (Gigantochloa psedoarundinacea) and betung (Dendrocalamus asper) with and without steam treatment. Strands were steam-treated at 126℃ for 1 h under 0.14 MPa pressure. The extractive content of bamboo strands before and after steam treatment were determined according to a standard (TAPPI T 204 om-88). Three-layer B-OSB with the core layer perpendicular to the surface and back layers were formed and binded with 8% of phenol formaldehyde (PF) resin with the addition of 1% of wax. The evaluation of physical and mechanical properties of the boards were conducted in accordance with the JIS A 5908:2003 standard. The results showed that steam treatment of bamboo strands significantly reduced the extractive content. Steam treatment tended to increase the dimensional stability and mechanical properties of B-OSB from andong and betung. The results showed that the dimensional stability and bending strength of B-OSB from betung was higher than those of andong. The internal bond strength of B-OSB from andong was higher than betung owing to a greater amount of extractives dissolved during the steam treatment.

< 전시-P-51 > Properties of Oriented Strand Board via Destructive and Non-destructive Test

( Sena Maulana ),( Rima V Ningsih ),( Fauzi Febrianto ),( I Nyoman J Wistara ),( Ihak Sumardi ) 한국목재공학회 2018 한국목재공학회 학술발표논문집 Vol.2018 No.1

Bamboo resources in Indonesia is abundant and have big potential to be development. Bamboo has been used as raw material for industry or construction. However bamboo also has some limitations when used for construction material, due to its diameter. Oriented strand board (OSB) is one of the alternative to increase the efficient utilization of bamboo for construction material. The objective of this study was to evaluate the properties of OSB on various shelling ratio and to evaluate the relation of mechanical properties of OSB via destructive and non-destructive testing. Strands were steamed at 126 oC for 1 h under 0.14 MPa. Three-layer OSB with core layer perpendicular to the surface and back layers were formed and binded with 8% of phenol formaldehyde (PF) resin with the addition of 1% of wax. Shelling ratio investigation of OSB was carried out by several types of strand with the ratio of face and core layer were 50:50, 55:45, 60:40, 65:35, 70:30, and 75:25 based on the strand oven dry weight on percent. From the result show that physical and mechanical properties of OSB that treated by steam was meet the requirement of CSA 0437 (Grade O-2) and EN 300 (Grade 2) standard. Non-destructive test using simple regression analyze was performed to analyze the statistic modulus elasticity (MOEs), modulus of rupture (MOR) of several shelling ratio. At shelling ratio 70:30 and 75:25 with parallel direction have higher mechanical properties as compared to perpendicular direction. OSB treated by steam has lower emission as compared to untreated OSB.

Destructive and Non-destructive Tests of Bamboo Oriented Strand Board under Various Shelling Ratios and Resin Contents

( Sena Maulana ),( Yuarsa Gumelar ),( Adesna Fatrawana ),( Muhammad Iqbal Maulana ),( Wahyu Hidayat ),( Ihak Sumardi ),( Nyoman Jaya Wistara ),( Seung Hwan Lee ),( Nam Hun Kim ),( Fauzi Febrianto ) 한국목재공학회 2019 목재공학 Vol.47 No.4

The objectives of this study were to evaluate the effects of shelling ratio and resin content on the properties of bamboo oriented strand board (BOSB) from betung (Dendrocalamus asper) and to determine the correlation between the results of dynamic and static bending tests. Strands were steam-treated at 126 ºC for 1 h under 0.14 MPa pressure and followed by washing with 1% NaOH solution. Three-layer BOSB with the core layer perpendicular to the surface was formed with shelling ratios (face:core ratio) of 30:70; 40:60; 50:50; 60:40 and binded with 7% and 8% of phenol formaldehyde (PF) resin with the addition of 1% of wax. The evaluation of physical and mechanical properties of BOSB was conducted in accordance with the JIS A 5908:2003 standard and the results were compared with CSA 0437.0 standard for commercial OSB (Grade O-1). Non-destructive testing was conducted using Metriguard Model 239A Stress Wave Timer which has a wave propagation time from 1 to 9,999 μs and a resolution of 1 μs. BOSB with 8% resin content showed better physical and mechanical properties than those with 7% resin content. The increase of the face layer ratio improved the strength of BOSB in parallel direction to the grain. The results suggested that shelling ratio of 50:50 could be used as a simple way to reduce PF resin requirements from 8% to 7% and to meet the requirements of CSA 0437.0 standard. The results of non-destructive and destructive tests showed a strong correlation, suggesting that non-destructive test can be used to estimate the bending properties of BOSB.

Physical and Mechanical Properties of Laminated Board from Betung Bamboo (Dendrocalamus asper)

Muhammad Navis Rofii,Michael Jose MAIRING,Tomy LISTYANTO,Ihak Sumardi,Rudi Hartono 한국목재공학회 2024 목재공학 Vol.52 No.4

Laminated bamboo is an engineered bamboo technology to maintain its mechanical durability for both construction and furniture materials. This study was conducted to assess the properties of laminated bamboo made from Betung bamboo at different culm positions and laminate orientations. The materials used in this study were 4-year Betung bamboo (Dendrocalamus asper) obtained from a community forest in Yogyakarta and polyvinyl acetate resin as adhesive. Two factors were applied for this study, i.e., culm position (lower, middle, and upper) and laminate orientations (vertical and horizontal direction). To examine the mechanical properties, a static bending test and the hardness test were performed in accordance with ASTM D1037-99. Moisture content and density were determined in accordance with BS 373-1957. The results indicated that there was no interaction between the culm position and laminate orientation on the moisture content, density, static bending properties and hardness. The culm position affected the static bending and hardness, with the higher position of the culm resulting a greater strength. The laminate orientation also affected the strength of laminated bamboo, with the vertical direction resulting in higher strength than the horizontal.

< 전시-P-54 > Destructive and Non-destructive Tests of Bamboo Oriented Strand Board under Various Shelling Ratio and Resin Content

( Sena Maulana ),( Muhammad Iqbal Maulana ),( Marwanto ),( Yuarsa Gumelar ),( Wahyu Hidayat ),( Nyoman Jaya Wistara ),( Ihak Sumardi ),( Fauzi Febrianto ),( Nam Hun Kim ) 한국목재공학회 2019 한국목재공학회 학술발표논문집 Vol.2019 No.1

The objective of this study was to evaluate the properties of bamboo oriented strand board (BOSB) from betung (Dendrocalamus asper ) bamboo using destructive and non-destructive methods under various shelling ratio and resin content. Strands were vacuum-treated at 126 ºC for 1 h under 0.14 MPa pressure and followed by washing with 1% NaOH solution. Three-layer BOSB (face:core:back) layers with the core layer perpendicular to the surface was formed with 15:70:15; 20:60:20; 25:50:25; 30:40:30 weight ratio and binded with 7 and 8% of phenol formaldehyde (PF) resin with the addition of 1% of wax. The evaluation of physical and mechanical properties of the boards was conducted in accordance with the JIS A 5908:2003 standard and compared with CSA 0437.0 standard for commercial OSB (Grade O-1). The results showed that BOSBs manufactured using 8% resin content with various core-to-face layer ratios had better physical and mechanical properties than using 7% resin content. Increasing core layer ratio increased the strength of BOSBs parallel to the grain. The face:core:back layers ratio of 25:50:25 could be used as a simple way to reduce PF resin requirements from 8% to 7%. Testing of non-destructive mechanical properties in betung BOSB has a high correlation with destructive testing.