scholarly journals Binderless MDF from Hydroxymethylated Kenaf Pulp

2018 ◽  
Vol 12 (1) ◽  
pp. 3
Author(s):  
Nyoman J Wistara ◽  
Wulan Starini ◽  
Fauzi Febrianto ◽  
Gustan Pari

Modified lignin with improved reactivity can be a potential alternative for synthetic phenol formaldehyde resin for the adhesive of wood composite. Direct hydroxymethylation of kenaf in the present experiments was intended to increase lignin reactivity, and therefore was expected to result in satisfying properties of binderless MDF. The stem of kenaf was refined in a disk refiner and the refined fibers were hydroxymethylated in various levels of alkalinity. The concentration of NaOH during hydroxymethylation was of 3%, 6% and 12%. Wet process was applied to produce MDF (30 cm x 30 cm x 1 cm) with target density of 0.65 g/cm³. Physical and mechanical properties of MDF were measured in accordance with the standard procedure of JIS A 5905: 2003. Chemical changes in the surface of pulp and the change of board crystallinity were evaluated by FTIR-KBr method and X-Ray Diffractometry (XRD), respectively. Density, moisture content, and screw withdrawal of the board increased with increasing of NaOH concentration. Thickness swelling, water absorption, MOE and MOR increased up to 3% concentration of NaOH. The IB and heat conductivity of MDF were not influenced by NaOH concentration. Increasing OH groups due to hydroxymethylation was thought to be the origin of high water absorption and thickness swelling of the resulting boards. Higher alkalinity during hydroxymethylation stage was likely increasing cellulose crystallinity that brought about increasing board density. However, chemical modification of the fiber was thought to be more influential to the bending strength and stiffness of the resulting fiberboard. Hydroxymethylation of kenaf pulp was successfully improved board properties. Except for the moisture content, thickness swelling and internal bonding (at 0% and 3% NaOH concentration), all properties of the MDF satisfied the requirement of JIS A 5905: 2003 (type 5) standard. MDF Tanpa Perekat dari Pulp Kenaf TerhidroksimetilasiIntisariLignin yang telah ditingkatkan reaktifitasnya dapat menjadi bahan alternatif perekat resin sintetis fenol formaldehida. Reaktivitas lignin dapat diperbaiki melalui hidroksimetilasi. Dalam penelitian ini, batang kenaf digiling menggunakan disk refiner, dan selanjutnya dilakukan hidroksimetilasi pada beragam alkalinitas. Konsentrasi NaOH yang digunakan dalam hidroksimetilasi bervariasi dari 3%, 6% dan 12%. Proses basah diterapkan untuk membuat MDF (30 cm x 30 cm x 1 cm) dengan target kerapatan 0,65 g/cm3. Sifat fisis dan mekanis MDF diukur mengikuti  prosedur standar JIS A 5905: 2003. Perubahan gugus fungsi permukaan pulp dan tingkat kristalinitas papan masing-masing dievaluasi menggunakan FTIR-metode KBr dan difraksi sinar X (XRD). Hasil penelitian menunjukkan bahwa konsentrasi NaOH tidak mempengaruhi IB dan konduktivitas panas MDF. Kerapatan, kadar air, dan kuat pegang sekrup cenderung meningkat dengan meningkatnya konsentrasi NaOH. Pengembangan tebal, daya serap air, MOE, dan MOR meningkat sampai dengan hidroksimetilasi dalam NaOH konsentrasi 3%. Peningkatan gugus OH serat akibat hidrosimetilasi diduga meningkatkan penyerapan air dan pengembangan tebal papan yang dihasilkan. Alkalinitas hidroksimetilasi yang lebih tinggi meningkatkan gugus cincin aromatik yang menunjukkan bahwa reaksi formaldehida berlangsung dengan lebih baik. Peningkatan alkalinitas dalam hidroksimetilasi meningkatkan kristalinitas selulosa. Peningkatan kristalinitas selulosa diduga berkontribusi dalam meningkatkan kerapatan, namun perubahan gugus kimia serat diduga lebih berpengaruh terhadap MOR dan MOE dari papan serat yang dihasilkan. Hidroksimetilasi pulp kenaf berhasil meningkatkan sifat papan. Kecuali untuk kadar air, pengembangan tebal dan IB (pada hidroksimetilasi dalam 0% dan 3% NaOH), semua sifat-sifat dari MDF yang dihasilkan memenuhi persyaratan standar JIS A 5905: 2003 (tipe 5).

2020 ◽  
Vol 111 ◽  
pp. 21-26
Author(s):  
Jakub Kawalerczyk ◽  
Dorota Dziurka ◽  
Radosław Mirski

The possible reduction of phenol-formaldehyde resin spread rate by its nanocellulose-reinforcement in plywood manufacturing process. The aim of the study was to investigate the possibility of phenol-formaldehyde (PF) resin consumption in plywood by its reinforcement with cellulosic nanoparticles (NCC). In order to determine the possible reduction of resin spread rate bonding quality was assessed both after boiling in water for 24h and after ageing test including i.e. boiling in water. Studies have shown that the addition of nanocellulose made it possible to significantly reduce the amount of the applied adhesive. Reference samples were characterized by similar shear strength values to experimental plywood manufactured with the adhesive application of 140 g/m2. NCC-reinforcement resulted also in the increase of mechanical properties such as modulus of elasticity and bending strength. The analysis of the data confirmed the tendency observed during bonding quality evaluation and it was concluded that resin modification allowed to reduce its spread rate by 30 g/m2.


2003 ◽  
Vol 14 (1) ◽  
pp. 36-42 ◽  
Author(s):  
Kensuke Kawarada ◽  
Hirotaka Nakanami ◽  
Takahiko Iida ◽  
Takayuki Okayama ◽  
Toshio Waku ◽  
...  

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 5422-5435
Author(s):  
Sena Maulana ◽  
Wahyu Hidayat ◽  
Ihak Sumardi ◽  
Nyoman J. Wistara ◽  
Muhammad I. Maulana ◽  
...  

Physical and mechanical properties were evaluated for bamboo-oriented strand boards (BOSB) prepared with combinations of two contrasting bamboo species and bonded with phenol formaldehyde resin under various compression ratios. The strands from the culms of Gigantochloa pseudoarundinacea and Dendrocalamus asper bamboo were steam-treated at a temperature of 126 °C and a pressure of 0.14 MPa for 1 h and then washed with a 1% NaOH solution. Three-layer dual-species bamboo-oriented strand boards with a shelling ratio of 25 to 50 to 25 (face to core to back) were manufactured with different compression ratios using an 8% phenol formaldehyde adhesive and 1% paraffin. The slenderness ratio and aspect ratio were evaluated by measuring 100 random strands to determine uniformity. The solidity profiles of the dual-species bamboo-oriented strand boards (thickness direction) were relatively uniform. The modulus of rupture, modulus of elasticity, and internal bond values of the dual-species bamboo-oriented strand boards increased as the compression ratio increased, but the water absorption and thickness swelling decreased. The dual-species bamboo-oriented strand boards prepared with compression ratios of 1.44 to 1.25 and 1.54 to 1.33 met all the requirements of CSA standard 0437 (2011). The optimum compression ratio for the preparation of dual-species bamboo-oriented strand boards was 1.44 to 1.25.


2019 ◽  
Vol 26 (3) ◽  
Author(s):  
Viviane Teixeira Iwakiri ◽  
Rosilani Trianoski ◽  
Dalton Luiz Razera ◽  
Setsuo Iwakiri ◽  
Thiago Souza da Rosa

ABSTRACT The objective of this work was to evaluate the feasibility of using lignin-phenol-formaldehyde resin in the production of Mimosa scabrella Benth (bracatinga) structural particleboard. The boards were produced with nominal specific mass of 0.75 and 0.95 g/cm3, 10% and 12% of phenol-formaldehyde and lignin-phenol-formaldehyde resins, with 10 and 12 min of pressing time. The boards quality was evaluated by means of the following physical-mechanical tests: specific mass, compression ratio, water absorption and thickness swelling after 2 and 24 hours soaking, perpendicular traction, static bending and screw pulling. Positive interactions of specific mass, resin content and pressing time were observed in the properties of the boards produced. The evaluation of the properties results based on the requirements of EN 312 (type P5) standard indicated the feasibility of using lignin-phenol-formaldehyde resin in the production of particleboard of Mimosa scabrellla for structural applications.


Forests ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 84 ◽  
Author(s):  
Susanne Bollmus ◽  
Cara Beeretz ◽  
Holger Militz

This study deals with the influence of chemical modification on elasto-mechanical properties of Scots pine (Pinus sylvestris L.). The elasto-mechanical properties examined were impact bending strength, determined by impact bending test; tensile strength; and work to maximum load in traction, determined by tensile tests. The modification agents used were one melamine-formaldehyde resin (MF), one low molecular weight phenol-formaldehyde resin, one higher molecular weight phenol-formaldehyde resin, and a dimethylol dihydroxyethyleneurea (DMDHEU). Special attention was paid to the influence of the solution concentration (0.5%, 5%, and 20%). With an increase in the concentration of each modification agent, the elasto-mechanical properties decreased as compared to the control specimens. Especially impact bending strength decreased greatly by modifications with the 0.5% solutions of each agent (by 37% to 47%). Modification with DMDHEU resulted in the highest overall reduction of the elasto-mechanical properties examined (up to 81% in work to maximum load in traction at 20% solution concentration). The results indicate that embrittlement is not primarily related to the degree of modification depended on used solution concentration. It is therefore assumed that molecular size and the resulting ability to penetrate into the cell wall could be crucial. The results show that, in the application of chemically modified wood, impact and tensile loads should be avoided even after treatment with low concentrations.


2016 ◽  
Vol 860 ◽  
pp. 73-77 ◽  
Author(s):  
Sergey Borisovich Vasilyev ◽  
Gennady Nikolaevich Kolesnikov ◽  
Aleksandr Vasilyevich Pitukhin ◽  
Nikolai Gennadievich Panov ◽  
Vadim Kostyukevich

The article presents the methods and the results of the experimental investigation of the additive influence of shungite nanopowder when mixed in the glue for three-ply particle board. The hypothesis of shungite nanopowder influence on physical-mechanical properties, water absorption and thickness swelling of wood particle board was formulated. The results of experimental investigations proved that the optimum shungite nanopowder quantity in glue solution makes up about 10 % of absolutely dry resin mass. Wooden particles of aspen and coniferous species, as well as glue solution based on carbamide-formaldehyde resin, were used in boards manufacturing. The samples were tested in order to determine physical-mechanical properties. It was found out that the 10 % shungite nanopowder additive increases the breaking point of three-ply particle board under bending strength by 18.3-25.7 %, the breaking point of three-ply particle board under tension perpendicular to the face of board by 7.5-11.7 %. As the result of experimental investigation it was found out that the 10 % shungite nanopowder when mixed in the glue decreases water thickness swelling of three-ply particle board up to 14.2 % and water absorption by 10.6-20.1 %. The shungite nanopowder powder contained particles of 50...100 nm in size and specific surface of 120 m2/g. In the course of the experiment three-ply particle boards were used with the thickness of 15.6 mm.


2010 ◽  
Vol 7 (1) ◽  
pp. 1
Author(s):  
Jamaludin Kasim ◽  
Siti Zalifah Mahmud ◽  
Nurrohana Ahmad ◽  
Shaikh Abdul Karim Yamani ◽  
Siti Nor Ain Tamiran ◽  
...  

Twenty five year old oil palm trunk supplied by MPOB, Bangi, Selangor, was converted into strands using a disk flaker and into particles using a dust extractor. Particleboard was produced using phenolic resin at 7, 9 and 11 % compositions based on particle weight used Particle size varied from 1.0-2.0 mm and the board density varied from 500-700 kg m-3. No significant improvement in MOR, MOE and IB was observed when the particle size was increased from 1.0 to 2.0 mm. However, with larger particle size the water absorption and thickness swelling properties improved. Increasing the resin content from 7-11 % significantly increases the mechanical properties and improves the water absorption and thickness swelling properties. Increasing the board density results in an increase in MOR, MOE and IB and a significant increase in the water absorption and thickness swelling properties. Particleboard with a high board density and resin content of more than 9 %met the minimum British Standard requirements. 


Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 135 ◽  
Author(s):  
Zhaoqing Li ◽  
Wangbing Zhou ◽  
Lei Yang ◽  
Peng Chen ◽  
Chunze Yan ◽  
...  

In this study, glass fiber (GF)/phenol formaldehyde resin (PF)/epoxy resin (EP) three-phase electrical insulating composites were fabricated by selective laser sintering (SLS) additive manufacturing technology and subsequent infiltration. In the three-phase composites, glass fibers modified by a silane coupling agent (KH-550) were used as reinforcements, phenol formaldehyde resin acted as the binder and matrix, and infiltrated epoxy resin was the filler. Mechanical and electrical properties such as tensile strength, bending strength, dielectric constant, electrical conductivity, and electric breakdown strength of the GF/PF/EP three-phase composite parts were investigated. The results indicated that after being infiltrated with EP, the bending strength and tensile strength of the GF/PF/EP composites increased by 30% and 42.8%, respectively. Moreover, the flexural strength and tensile strength of the GF/PF/EP composite increased with the increase of the glass fiber content. More importantly, the three-phase composites showed high electrical properties. Significant improvement in the dielectric constant, electric breakdown strength, and resistivity with the increase in the content of glass fiber was observed. This enables the prepared GF/PF/EP composites to form complex structural electrical insulation devices by SLS, which expands the materials and applications of additive manufacturing technology.


2021 ◽  
Vol 17 (2) ◽  
pp. 152-159
Author(s):  
Rynaldo Davinsy ◽  
Sena Maulana ◽  
Muhammad I Maulana ◽  
Elvara D Satria ◽  
Deded S Nawawi ◽  
...  

Hybrid Bamboo Oriented Strand Boards (OSB) were produced to improve bamboo OSB's physical and mechanical properties. Shelling ratio adjustment of the strand type combination could determine the optimal physical and mechanical properties of hybrid bamboo oriented strand boards (OSB). The purpose of this study was to evaluate the physical and mechanical properties of hybrid betung and andong bamboos OSB at various shelling ratios. Steam modified strands of betung and andong bamboo were used as an outer layer and core layer, respectively. Hybrid bamboo OSBs were prepared with 0.7 g cm-3 target density and 8% phenol-formaldehyde resin content. Three layers of OSB were made with outer: core shelling ratios of 30:70, 40:60, 50:50, and 60:40. The physical and mechanical properties of the OSB were tested referring to the JIS A 5908-2003 standard. The targeted board density was achieved and the physical properties of all hybrid bamboo OSB have met the requirement of CSA O437.0 (Grade O-1) standard criteria. The parallel modulus of elasticity (MOE) and modulus of rupture (MOR) increased with increasing outer layer ratio. However, the perpendicular MOE and MOR decreased with increasing outer layer ratio. The internal bonding (IB) of the OSB with a shelling ratio of 30:70 and 40:60 met with the requirement of the CSA O437.0 (Grade O-1) standard.


2020 ◽  
Vol 2 (2) ◽  
pp. 131-138

The main objective of the present study was to modify phenol-formaldehyde (PF) resin by using bio-oil obtained by pyrolysis with and without alkali catalyst (potassium carbonate: K2CO3) (10 to 50 weight %) and determine technological properties oriented strandboard (OSB) panels produced using the modified PF resin formulations. The pine sawdust was used as a raw material of bio-oil. The chemical characterization of bio-oils was determined by GC-MS analysis. The OSB panels were produced with the bio-based PF resins and then their technological properties were determined. As the amount of potassium carbonate catalyst increased up to 20 wt% in the PF resin, 24-h thickness swelling of OSB panels decreased from 15.4 to 14.3%, but further increment in the potassium carbonate catalyst content increased the thickness swelling (22.8%). The IB strength of the OSB specimens with PF resin with 10 wt% bio-oil produced with catalyst or pyrolysis process was found the same (2.18 N/mm2) and it was higher than the reference value (1.97 N/mm2). As the amount of bio-oil was increased to 20 wt%, the difference in the IB values between treated OSB and reference OSB was negligible. However, above the 20 wt% bio oil, it was observed a decreasing trend in the IB values. The bending strength and bending modulus of the OSB specimens containing 20 wt% bio-oil were also found to be higher than those of the reference OSB specimens. It was concluded that the PF resin synthesized using bio-oil of (20 wt%) produced with and without alkali catalyst could be successfully used in the production of the OSB.


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