Properties of thermally modified medium-density fibreboards

Holzforschung ◽  
2012 ◽  
Vol 66 (1) ◽  
Author(s):  
Jürgen Bonigut ◽  
Detlef Krug ◽  
Beate Stephani
Keyword(s):  
Thermal Treatment ◽  
Moisture Content ◽  
Equilibrium Moisture Content ◽  
Phenol Formaldehyde ◽  
Creep Behaviour ◽  
Modulus Of Rupture ◽  
Medium Density ◽  
Thickness Swelling ◽  
Short Term ◽  
European Standards

Abstract Thermal treatment of solid timber and oriented strandboards (OSB) improves durability against fungal decay and dimensional stability (swelling and shrinking). It is not clear whether thermal treatment of medium-density fibreboards (MDF) has the same effects. In this work, four variants of phenol-formaldehyde (PF)-bonded MDF with varying contents of resin and hydrophobing agent were thermally post-treated according to the Mühlböck procedure at three different maxi-mum temperatures. The short-term properties internal bond, modulus of rupture, modulus of elasticity, thickness swelling and equilibrium moisture content and the long-term property creep behaviour of treated variants and of one untreated variant have been tested. The results are presented and discussed in comparison with the respective European standards. Altogether, the thermal treatment had a positive effect on most of the tested mechanical short-term properties. The moisture-related properties, i.e., thickness swelling and equilibrium moisture content, were also positively influenced. The creep behaviour of heat-treated MDF could also be improved by thermal modification.

Medium Density Particleboard with Addition of Impregnated Paper

2014 ◽  
Vol 1025-1026 ◽  
pp. 543-546
Author(s):  
Juliana Cortez Barbosa ◽  
Anderson Luiz da Silva Michelon ◽  
Elen Aparecida Martines Morales ◽  
Cristiane Inácio de Campos ◽  
André Luis Christoforo ◽  
...  
Keyword(s):  
Moisture Content ◽  
Modulus Of Elasticity ◽  
Mechanical Tests ◽  
Modulus Of Rupture ◽  
Medium Density ◽  
Test Results ◽  
Thickness Swelling ◽  
Adhesion Test ◽  
Layer Medium ◽  
Determine Moisture Content

The aim of this research was to produce three-layer Medium Density Particleboard (MDP), with the addition of impregnated paper, in the inner layer, in proportions of 1; 5 and 20%. In this study, MDP was composed with particles of small size in outer layers, and larger particles in internal layer. After panel manufacturing, physical and mechanical tests based on Brazilian Code ABNT NBR 14.810 were carried out to determine moisture content; density; thickness swelling; water absorption; modulus of rupture (MOR) and modulus of elasticity (MOE) in static bending and internal adhesion. Test results were compared to commercial panels, produced with 100% Eucalyptus, considering the requirements specified by Brazilian Code. Properties presented values close to normative specifications, indicating positively the possibility of production of MDP using addition of waste paper impregnated.

Wood-Based Panels’ Properties when Subject to Temperature and Humidity Variation

2013 ◽  
Vol 787 ◽  
pp. 106-110
Author(s):  
Hai Xia Yu ◽  
Man Ping Xu ◽  
Chong Rong Fang ◽  
Fei Yan Guo
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Moisture Content ◽  
Internal Bond ◽  
Modulus Of Rupture ◽  
High Humidity ◽  
Thickness Swelling ◽  
Temperature And Humidity ◽  
Low Humidity ◽  
European Standards

In order to reveal impact of environment humidity and temperature on properties of indoor decorated materials, the paper tested physical and mechanical prosperities of 5 kinds of wood-based panels according to European standards after equilibrium treatments in 3 types of atmosphere. The results showed that the tested materials were very hydrophilic and their strength were closely related to moisture content. Internal bond, modulus of rupture, 24h-thickness swelling and surface soundness of wood-based panels decreased at high temperature and high humidity atmosphere and increased in low temperature and low humidity surroundings, and the decrement are greater than the increment. In contrast, density almost kept the same value during these treatments.

scholarly journals KUALITAS PAPAN KOMPOSIT LIMBAH KULIT BATANG SAGU (Metroxylon sp) DAN PLASTIK POLIPROPILENA BERDASARKAN JUMLAH LAPISAN PENYUSUN

2018 ◽  
Vol 7 (1) ◽  
Author(s):  
Mayang Archila ◽  
Farah Diba ◽  
Dina Setyawati ◽  
. Nurhaida
Keyword(s):  
Mechanical Properties ◽  
Moisture Content ◽  
Physical And Mechanical Properties ◽  
Modulus Of Rupture ◽  
Internal Bonding ◽  
Thickness Swelling ◽  
Composite Board ◽  
Average Value ◽  
Composite Layers ◽  
Sago Bark

The objective of this research is to evaluate the effect of the number of composite layers on the quality of the composite board from sago bark waste and plastic waste, and the number of composite layers that produce the best quality on composite board. The composite board is made with size 30 cm x 30 cm x 1 cm. The composition and division of the material was carried out manually with the polypropylene distribution divided into three parts: the front and rear respectively of 15%, and the center 70% of the plastic weight. Target density of composite boards was 0.7 g / cm3. The treatment used is based on the number of layers composing, which is 5 layers, 7 layers, 9 layers, 11 layers and 13 layers. After mixed the sago bark particle and waste of polypropylene, the materials then compressed with hot press at 180oC with pressure about ± 25 kg / cm2 for 10 minutes. The composite boards then tested the quality included physical and mechanical properties. Testing of physical and mechanical properties refers to JIS A 5908-2003 standard. Physical properties consist of density, moisture content, thickness swelling, and water absorption. Mechanical properties consist of modulus of rupture, modulus of elasticity, internal bonding, and modulus of screw holding strength. The study used a completely randomized design experiment consisting of 5 treatments and 3 replications. The results showed the average value of composite density was range between 0.6962 – 0.7896 g/cm3, the moisture content was range between 4.3388 % - 6.8066%, the thickness swelling was range between 8.2605% - 11.9615%, and water absorption was range between 17.2380% - 22.3867%. The average value of modulus of rupture was range between 60,0632 kg/cm2 – 64,4068 kg/cm2, the modulus of elasticity was range between 17935,1813g/cm2 – 32841,8278 kg/cm2, the internal bonding was range between 1,9268 kg/cm2  - 5,4119 kg/cm2, and the modulus of screw holding strength was range between 78,2530 kg/cm2 – 92,9677 kg/cm2. The composite board made from sago stem bark waste and polypropylene waste plastic with 13 layers treatment is the best composite board and fulfilled the JIS A 5908-2003 standard. Keywords: bark of sago, composite boards, layer of composite, polypropylenes plastic, waste

scholarly journals INFLUENCE OF THERMAL MODIFICATION ON THE PHYSICAL AND MECHANICAL PROPERTIES OF Eucalyptus badjensis MIXED PARTICLEBOARD / OSB PANELS

FLORESTA ◽  
2021 ◽  
Vol 51 (2) ◽  
pp. 419
Author(s):  
Giuliano Ferreira Pereira ◽  
Setsuo Iwakiri ◽  
Rosilani Trianoski ◽  
Polliana D'angelo Rios ◽  
Renan Zunta Raia
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Phenol Formaldehyde ◽  
Physical And Mechanical Properties ◽  
Dry Mass ◽  
Thermal Modification ◽  
Modulus Of Rupture ◽  
Thickness Swelling ◽  
Swelling Properties ◽  
Different Temperatures

The objective of this research was to evaluate the effects of thermal modifications, at different temperatures and exposure times, on the technological properties of mixed particleboard / OSB panels made out of Eucalyptus badjensis. Using the wood of Eucalyptus badjensis, Particleboard, OSB and mixed Particleboard/OSB panels (control and thermally modified) were manufactured. The mixed panels’ thermal modification was carried out under three temperatures (180ºC, 200ºC and 220ºC) and two exposure times (10 minutes and 12 minutes). For the panels’ manufacturing, 6% of phenol-formaldehyde adhesive and 1% of paraffin were employed, which was calculated based on the particles’ dry mass. The water absorption and thickness swelling properties were evaluated after 2 and 24 hours of immersion, in addition to the panels’ modulus of elasticity, modulus of rupture and internal bond. Based on the results, we were able to conclude that the thermal modification affected most of the physical properties positively. From the different exposure times studied, the most effective one was the period of 12 minutes, especially for water absorption after 2 hours, which caused a reduction of 11.27%. In turn, the most effective temperature was of 220ºC, highlighting the thickness swelling after 24 hours, which caused a swelling decrease of 23.76% in comparison with the control panels. Regarding the mechanical properties, the thermal modification, in terms of the studied exposure times and temperatures, did not affect the results of the mixed particleboard /OSB panels. 

scholarly journals Effects of thermo-hydro-mechanical treatments on various physical and mechanical properties of poplar (Populus) wood

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 9596-9610
Author(s):  
Yali Shao ◽  
Lili Li ◽  
Zhangjing Chen ◽  
Sunguo Wang ◽  
Ximing Wang
Keyword(s):  
Mechanical Properties ◽  
Thermal Treatment ◽  
Modulus Of Elasticity ◽  
Mechanical Treatment ◽  
Elasticity Modulus ◽  
Physical And Mechanical Properties ◽  
Modulus Of Rupture ◽  
Compression Rate ◽  
Thickness Swelling ◽  
Maximum Thickness

Poplar (Populus) wood was subjected in this work to thermo-hydro-mechanical treatment. The influence of the treatment parameters on the physical and mechanical properties were investigated. The wood samples were densified under three compression ratios (0%, 30%, and 50%), and thermally treated at three temperatures (180 °C, 200 °C, and 220 °C), at three thermal treatment durations (3 h, 4 h, and 5 h). The density, modulus of elasticity, modulus of rupture, radial hardness, and thickness swelling were measured. The results showed that the densities of the samples increased by 36.6% to 49.7%. As the compression rate increased, the temperature, duration, modulus of elasticity, modulus of rupture, and hardness increased. However, the dimensions of the densified samples were less stable. Compared to the densified samples, the maximum thickness swelling could be reduced by 74% (from 29.7% to 7.8%) when subjected to a thermal treatment at 220 °C for 3 h.

scholarly journals Properties of dual-species bamboo-oriented strand boards bonded with phenol formaldehyde adhesive under various compression ratios

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 5422-5435
Author(s):  
Sena Maulana ◽  
Wahyu Hidayat ◽  
Ihak Sumardi ◽  
Nyoman J. Wistara ◽  
Muhammad I. Maulana ◽  
...  
Keyword(s):  
Compression Ratio ◽  
Phenol Formaldehyde ◽  
Slenderness Ratio ◽  
Physical And Mechanical Properties ◽  
Phenol Formaldehyde Resin ◽  
Modulus Of Rupture ◽  
Formaldehyde Resin ◽  
Thickness Swelling ◽  
Naoh Solution ◽  
Dendrocalamus Asper

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.

scholarly journals Properties of Particleboard from Sawmill Wastes and Rubberwood (Hevea brasiliensis) with Different Board Thickness and Resin Content

2019 ◽  
Vol 8 (4) ◽  
pp. 6808-6812
Keyword(s):  
Mechanical Properties ◽  
Modulus Of Elasticity ◽  
Hevea Brasiliensis ◽  
Urea Formaldehyde ◽  
Resin Content ◽  
Modulus Of Rupture ◽  
Internal Bonding ◽  
Thickness Swelling ◽  
Board Thickness ◽  
European Standards

This study investigate the effect of the board thickness and resin content on the properties of particleboard. Single-layered sawmill wastes and rubberwood particleboards bonded with urea formaldehyde (UF) resins were manufactured. The boards were fabricated with three different board thicknesses (15, 18 and 25mm) at three different resin contents (7, 8 and 9%). The boards produced were evaluated for their modulus of elasticity (MOE), modulus of rupture (MOR), internal bonding (IB) and thickness swelling (TS) in accordance with the European Standards. Board thickness does affect the mechanical properties of particleboard. The study revealed that thinner boards gave higher MOE, MOR, IB and TS. No significant effects were found among three resin contents for MOE, MOR, IB and TS. It can be concluded that the particleboard made from mix tropical wood from sawmill waste and with rubberwood were suitable for particleboard manufacturing.

scholarly journals Pengaruh Suhu dan Waktu Kempa Terhadap Sifat Fisik dan Mekanik Papan Komposit dari Serat Tkks Berperekat Gambir Berlapis Anyaman Bambu

2018 ◽  
Vol 13 (2) ◽  
pp. 54
Author(s):  
Junaidi -
Keyword(s):  
Moisture Content ◽  
Physical And Mechanical Properties ◽  
Layered Composite ◽  
National Standards ◽  
Raw Material ◽  
Modulus Of Rupture ◽  
Thickness Swelling ◽  
Composite Board ◽  
Empty Fruit Bunches ◽  
Pressing Time

Fiber from oil palm empty fruit bunches (OPEFB) can be used as a raw material for the production of composite board.  Gambier can be used in a natural adhesive because of its high tannin content.  Appropriate material to veneer the board and the correct temperature and pressing time are needed to improve the quality of this composite board. This research was to discover the optimal temperature, needed to make woven bamboo veneer composite board from OPEFB fiber and  gambier based adhesive that can fulfill the Indonesian National Standards for veneered composite boards and the pressing time required for the board to reach thermal equilibrium. Results showed that both temperature and pressing time have a significant influence on density, moisture content, thickness swelling and modulus of rupture (MOR) of the boards but not on the internal bond strength or the compression strength parallel to the grain.  Multi-layered composite board pressed at 1300C has weaker physical and mechanical properties than that pressed at  1450C, or 1600C.  Twenty-five minutes of pressing time yielded a better product than 15 minutes and the combination of 25 minutes and 1450C proved to be optimal for the curing of the gambier based adhesive used with 8.4% moisture content fibers. Use of woven bamboo veneer resulted in boards that reached the density, moisture content, thickness swelling at 24 hours (PT24) and MOR National standards SNI 03-2105-2006 for standard veneered particle board however it failed to reach the standard for modulus of elasticity (MOE). The bonding strength of the boards reached the Nation Standard SNI 01-5008.7-1999 of 3.5 kg/cm2 minimum for structural veneered boards.

scholarly journals Drying performance, as well as physical and flexural properties of oil palm wood dried via the super-fast drying method

BioResources ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. 1674-1685
Author(s):  
Mohd Rafsan Rais ◽  
Edi Suhaimi Bakar ◽  
Zaidon Ashaari ◽  
Lee Seng Hua ◽  
Mojtaba Soltani ◽  
...  
Keyword(s):  
Moisture Content ◽  
Oil Palm ◽  
Modulus Of Rupture ◽  
Flexural Properties ◽  
Total Thickness ◽  
Drying Method ◽  
Thickness Swelling ◽  
Board Density ◽  
Hole Depth ◽  
Specific Modulus

Effects of incising parameters were studied relative to the drying performance and properties of super–fast dried oil palm wood. Different incising depths (1/3, 1/2, 2/3, and 100% of the total thickness) and distance (38 mm and 50 mm) were made on the oil palm wood boards prior to the super-fast drying procedure. All the boards achieved the desired moisture content after drying. Drying defects were minimal, as only two boards indicated end checks and surface checks defects. The board density ranged from 0.44 g/m3 to 0.60 g/m3, and the thickness swelling and water absorption of the boards ranged from 8.3% to 12.5% and 45% to 67%, respectively. The specific modulus of rupture and elasticty ranged from 0.35 N m3/kg mm2 to 0.77 N m3/kg mm2 and from 77.64 N m3/kg mm2 to 118.40 N m3/kg mm2, respectively. It can be concluded that the hole distances did not exert significant effect on the properties, with exception of specific modulus of elasticity. A hole depth of 1/3 mm was preferable, since the surface looked like no incision had been made and the sample had good physical and flexural properties.

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
Keyword(s):  
Moisture Content ◽  
Water Absorption ◽  
Bending Strength ◽  
Phenol Formaldehyde ◽  
Standard Procedure ◽  
Phenol Formaldehyde Resin ◽  
Formaldehyde Resin ◽  
Thickness Swelling ◽  
Board Density ◽  
Oh Groups

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).

Sign in / Sign up

Export Citation Format

Share Document