scholarly journals Properties of High Density Fiberboard Mixed with Poplar Bark

2020 ◽  
Vol 17 (12) ◽  
pp. 1286-1293
Author(s):  
Zoltán PÁSZTORY ◽  
Katalin HALÁSZ ◽  
Zoltán BÖRCSÖK ◽  
Suthon SRIVARO
Keyword(s):  
Mechanical Properties ◽  
Health Risk ◽  
Indoor Air ◽  
Color Change ◽  
Urea Formaldehyde ◽  
Chemical Compounds ◽  
Dry Weight ◽  
Wood Products ◽  
Raw Material ◽  
Formaldehyde Resin

Formaldehyde in the indoor air is one of the chemicals which can cause health risk; therefore, researchers have strived to reduce formaldehyde emissions from different wood products. There are many chemical compounds in bark, including tannins, which can react with formaldehyde. The aim of this study was to reduce the formaldehyde emissions from HDF by mixing poplar bark powder into the raw material. 2, 4, 6, and 8 % (based on dry weight) Populus×euramericana bark was mixed with fibers, and HDF panels were manufactured with urea-formaldehyde resin. Mechanical properties, color change, and formaldehyde release were measured. Contrary to expectations, the mixed bark did not reduce formaldehyde emissions, but the mechanical properties deteriorated due to the bark powder. Formaldehyde emissions were reduced only in the case of 2 % added bark; in cases of 4, 6, and 8 %, the emissions increased.

scholarly journals Improving Thermal Conductivity Coefficient in Oriented Strand Lumber (OSL) Using Sepiolite

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 599 ◽  
Author(s):  
Hamid R. Taghiyari ◽  
Abolfazl Soltani ◽  
Ayoub Esmailpour ◽  
Vahid Hassani ◽  
Hamed Gholipour ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Core Temperature ◽  
Thermal Conductivity Coefficient ◽  
Urea Formaldehyde ◽  
Wood Products ◽  
Raw Material ◽  
Formaldehyde Resin ◽  
The Core ◽  
Uf Resin ◽  
Hardness Values

An issue in engineered wood products, like oriented strand lumber (OSL), is the low thermal conductivity coefficient of raw material, preventing the fast transfer of heat into the core of composite mats. The aim of this paper is to investigate the effect of sepiolite at nanoscale with aspect ratio of 1:15, in mixture with urea-formaldehyde resin (UF), and its effect on thermal conductivity coefficient of the final panel. Sepiolite was mixed with UF resin for 20 min prior to being sprayed onto wood strips in a rotary drum. Ten percent of sepiolite was mixed with the resin, based on the dry weight of UF resin. OSL panels with two resin contents, namely 8% and 10%, were manufactured. Temperature was measured at the core section of the mat at 5-second intervals, using a digital thermometer. The thermal conductivity coefficient of OSL specimens was calculated based on Fourier’s Law for heat conduction. With regard to the fact that an improved thermal conductivity would ultimately be translated into a more effective polymerization of the resin, hardness of the panel was measured, at different depths of penetration of the Janka ball, to find out how the improved conductivity affected the hardness of the produced composite panels. The measurement of core temperature in OSL panels revealed that sepiolite-treated panels with 10% resin content had a higher core temperature in comparison to the ones containing 8% resin. Furthermore, it was revealed that the addition of sepiolite increased thermal conductivity in OSL panels made with 8% and 10% resin contents, by 36% and 40%, respectively. The addition of sepiolite significantly increased hardness values in all penetration depths. Hardness increased as sepiolite content increased. Considering the fact that the amount of sepiolite content was very low, and therefore it could not physically impact hardness increase, the significant increase in hardness values was attributed to the improvement in the thermal conductivity of panels and subsequent, more complete, curing of resin.

scholarly journals Low viscosity melamine urea formaldehyde resin as a bulking agent in reducing formaldehyde emission of treated wood

BioResources ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. 2195-2211
Author(s):  
Rabiatol Adawiah Mohd Ali ◽  
Zaidon Ashaari ◽  
Seng Hua Lee ◽  
Mohd Khairun Anwar Uyup ◽  
Edi Suhaimi Bakar ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Dimensional Stability ◽  
Urea Formaldehyde ◽  
Treated Wood ◽  
Physical And Mechanical Properties ◽  
Formaldehyde Emission ◽  
Wood Products ◽  
Formaldehyde Resin ◽  
Low Viscosity ◽  
Resin Impregnation

Melamine urea formaldehyde (MUF) resin impregnation followed by heat compression is a prominent method in improving mechanical properties and dimensional stability of wood. In addition, melamine is reactive to formaldehyde, and therefore able to reduce the free formaldehyde of the treated wood. This study aimed to produce compressed sesenduk (Endospermum diadenum) wood with low formaldehyde emission using low viscosity MUF resin. The effects of treatment efficiency on the physical and mechanical properties of the wood products were evaluated. The experimental design included impregnation of sesenduk strips with 20% and 30% MUF at five different formulations. Then, it was pre-cured at a temperature of 70 °C for 90 min, followed by hot compression at 140 °C with the compression ratio of 80%. The optimum treatment combination was determined through treatability, mechanical strength, dimensional stability, and formaldehyde emission. It was also compared to other treatments, including impregnation without further compression using formulated MUF and commercial MUF. The results revealed that F4 MUF, which consisted of 30% melamine, 50% formaldehyde, and 20% urea, was the optimal MUF formulation that resulted in low formaldehyde emission and acceptable physical and mechanical properties.

scholarly journals Suitability of Muli Bamboo (Melocanna baccifera) for Making Bamboo Mat Plywood

1970 ◽  
Vol 46 (4) ◽  
pp. 543-548 ◽  
Author(s):  
M Ashaduzzaman ◽  
R Rana ◽  
MNH Khan ◽  
MI Shams
Keyword(s):  
Mechanical Properties ◽  
Modulus Of Elasticity ◽  
Urea Formaldehyde ◽  
Physical And Mechanical Properties ◽  
High Strength ◽  
Average Density ◽  
Raw Material ◽  
Modulus Of Rupture ◽  
Formaldehyde Resin ◽  
Alternative Source

This paper investigated the potentiality of muli (Melocanna baccifera) for making bamboo mat plywood. Bamboo mat plywood with the length, width and thickness of 2.4 m × 1.2 m × 7 mm was made using liquid urea formaldehyde resin. The physical and mechanical properties of such plywood were compared with the existing market plywood. The average density of bamboo mat plywood was much higher compared to the existing market plywood. The modulus of rupture (MOR) of bamboo mat plywood was 3 times and the modulus of elasticity (MOE) was 6 times higher compared to commercial (Bombax ceiba) plywood. Interestingly, the specific MOR and MOE were significantly higher than those of market plywood. The high strength values might be due to the long fiber length of the bamboo. Furthermore, the lamination of decorative thin garjan (Dipterocarpus turbinatus) veneer did not significantly reduce mechanical properties of the products. Bamboo plywood mat as well as garjan laminated bamboo mat plywood showed better performance in respect to thickness swelling, linear expansion and water absorption. Hence, muli bamboo can be a potential alternative source of raw material for the manufacture of plywood materials. Key words: Bamboo mat plywood; Density; Dimensional stability; Modulus of elasticity; Modulus of rupture DOI: http://dx.doi.org/10.3329/bjsir.v46i4.9605 BJSIR 2011; 46(4): 543-548

Manufacture of thin rice straw particleboards bonded with various polymeric methane diphenyl diisocyanate/ urea formaldehyde resin mixtures

BioResources ◽  
2019 ◽  
Vol 15 (1) ◽  
pp. 935-944
Author(s):  
Peng Luo ◽  
Chuanmin Yang ◽  
Mengyao Li ◽  
Yueqi Wang
Keyword(s):  
Mechanical Properties ◽  
Rice Straw ◽  
Water Resistance ◽  
Urea Formaldehyde ◽  
Single Layer ◽  
Formaldehyde Resin ◽  
Manufacturing Cost ◽  
Board Density ◽  
Layer Medium ◽  
Resin Formulation

Reducing particleboard thickness is one of the major approaches to decrease consumption volume of particleboard for furniture manufacture. This study employed an adhesive mixture of polymeric methane diphenyl diisocyanate (PMDI) and urea formaldehyde (UF) to produce single-layer medium density thin rice straw particleboard. The effects of various PMDI/UF formulations as well as board density on mechanical properties and water resistance of rice straw particleboard were studied. The results indicated that the mechanical properties and water resistance of the thin rice straw particleboard were appreciably affected by resin formulation. The panels bonded with PMDI/UF adhesive mixtures had mechanical properties and water resistance far superior to those bonded with UF. Higher PMDI content levels in resin mixtures led to improved mechanical properties and water resistance. Density influenced mechanical properties and water resistance of the thin rice straw particleboard. Increasing the density of the panel could upgrade the mechanical properties of the thin rice straw particleboard. The experimental outcomes showed that PMDI/UF resin systems had potential to substitute for pure PMDI resin in producing thin rice straw particleboard, which could effectively lower manufacturing cost and bring economic efficiencies due to reduced amount of pricey PMDI.

scholarly journals Particleboards from Recycled Thermally Modified Wood

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1462
Author(s):  
Ján Iždinský ◽  
Zuzana Vidholdová ◽  
Ladislav Reinprecht
Keyword(s):  
Mechanical Properties ◽  
Urea Formaldehyde ◽  
Brown Rot ◽  
Decay Resistance ◽  
Raw Material ◽  
Modulus Of Rupture ◽  
Negative Effect ◽  
Serpula Lacrymans ◽  
Thermally Modified Wood ◽  
Modified Wood

In recent years, the production and consumption of thermally modified wood (TMW) has been increasing. Offcuts and other waste generated during TMWs processing into products, as well as already disposed products based on TMWs can be an input recycled raw material for production of particleboards (PBs). In a laboratory, 16 mm thick 3-layer PBs bonded with urea-formaldehyde (UF) resin were produced at 5.8 MPa, 240 °C and 8 s pressing factor. In PBs, the particles from fresh spruce wood and mixed particles from offcuts of pine, beech, and ash TMWs were combined in weight ratios of 100:0, 80:20, 50:50 and 0:100. Thickness swelling (TS) and water absorption (WA) of PBs decreased with increased portion of TMW particles, i.e., TS after 24 h maximally about 72.3% and WA after 24 h maximally about 64%. However, mechanical properties of PBs worsened proportionally with a higher content of recycled TMW—apparently, the modulus of rupture (MOR) up to 55.5% and internal bond (IB) up to 46.2%, while negative effect of TMW particles on the modulus of elasticity (MOE) was milder. Decay resistance of PBs to the brown-rot fungus Serpula lacrymans (Schumacher ex Fries) S.F.Gray increased if they contained TMW particles, maximally about 45%, while the mould resistance of PBs containing TMW particles improved only in the first days of test. In summary, the recycled TMW particles can improve the decay and water resistance of PBs exposed to higher humidity environment. However, worsening of their mechanical properties could appear, as well.

Mechanical Strength of Sago/Urea Formaldehyde Particleboard Affected by the Particle Size

2016 ◽  
Vol 833 ◽  
pp. 3-10
Author(s):  
Tay Chen Chiang ◽  
Sinin Hamdan ◽  
Mohd Shahril Osman
Keyword(s):  
Mechanical Properties ◽  
Manufacturing Industry ◽  
Urea Formaldehyde ◽  
Great Influence ◽  
Single Layer ◽  
Milling Process ◽  
Raw Material ◽  
Huge Amount ◽  
Testing Method ◽  
Sago Waste

Every year, the sago processing industry in Sarawak-Mukah had generated huge amount of sago waste after the milling process and scientists have employ the waste into composite material. The fabrication and testing method are based on the Japanese A5908 Industrial Standard. Single-layer particleboards with targeted density of 600kg/m3 were produced from different sizes of sago particles. The mechanical properties of sago waste were investigated to study the feasibility of using this sample as a raw material in particleboard manufacturing. The results of the test demonstrate that samples with different sizes of particles have great influence on the mechanical properties such as Young’s Modulus, Tensile Strength and Impact Strength. The findings show that the performance of the board is affected by the different sizes of sago particles used in the experiment and had proved that sago plants can be used as an alternative raw material in the particleboard manufacturing industry.

scholarly journals Physical and Mechanical Properties of Binderless Particleboard Made from Steam-Pretreated Oil Palm Trunk Particles

2019 ◽  
Vol 3 (2) ◽  
pp. 46 ◽  
Author(s):  
Jia Geng Boon ◽  
Rokiah Hashim ◽  
Mohammed Danish ◽  
Wan Noor Aidawati Wan Nadhari
Keyword(s):  
Mechanical Properties ◽  
Oil Palm ◽  
Chemical Constituents ◽  
Starch Content ◽  
Urea Formaldehyde ◽  
Health And Safety ◽  
Physical And Mechanical Properties ◽  
Steam Pretreatment ◽  
Formaldehyde Resin ◽  
Oil Palm Trunk

Formaldehyde emissions from conventional particleboards raise issues of health and safety. One of the potential solutions is binderless particleboards made without using synthetic adhesives. However, the physical and mechanical properties of untreated binderless particleboards are relatively poor compared to conventional particleboards. This research aims to reveal the potential of using steam pretreatment to improve binderless particleboard properties made from oil palm trunk. The oil palm trunk particles were treated with steam pretreatment for different durations of time (20, 40, 60 min). The chemical constituents of the treated and untreated particles were evaluated. The binderless particleboards were made from treated and untreated particles. In addition, panels using untreated oil palm trunk particles with 10% urea–formaldehyde resin were made and used as a comparison. The boards were evaluated according to European Standards. The results indicated that the hemicellulose and starch content gradually reduced with the progression of steam pretreatment. The physical and mechanical properties were improved by increasing steam pretreatment duration. The steam pretreatment was able to improve the properties of binderless particleboards made from oil palm trunk. However, the performance of steam-pretreated binderless particleboard in this study is not compatible with the particleboards made using 10% urea–formaldehyde.

scholarly journals Research Progress of Wood-Based Panels Made of Thermoplastics as Wood Adhesives

Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 98
Author(s):  
Xianfeng Mo ◽  
Xinhao Zhang ◽  
Lu Fang ◽  
Yu Zhang
Keyword(s):  
Production Efficiency ◽  
Urea Formaldehyde ◽  
Formaldehyde Emission ◽  
Raw Material ◽  
Research Progress ◽  
Formaldehyde Resin ◽  
Wood Adhesives ◽  
Bonding Structure ◽  
Existing Problems ◽  
Thermoplastic Resins

When thermoplastic resins such as polyethylene (PE) and polypropylene (PP) are selected as wood adhesives to bond wood particles (fibers, chips, veneers) by using the hot-pressing technique, the formaldehyde emission issue that has long existed in the wood-based panel industry can be effectively solved. In this study, in general, thermoplastic-bonded wood-based panels presented relatively higher mechanical properties and better water resistance and machinability than the conventional urea–formaldehyde resin-bonded wood-based panels. However, the bonding structure of the wood and thermoplastic materials was unstable at high temperatures. Compared with the wood–plastic composites manufactured by the extruding or injection molding methods, thermoplastic-bonded wood-based panels have the advantages of larger size, a wider raw material range and higher production efficiency. The processing technology, bonding mechanism and the performance of thermoplastic-bonded wood-based panels are comprehensively summarized and reviewed in this paper. Meanwhile, the existing problems of this new kind of panel and their future development trends are also highlighted, which can provide the wood industry with foundations and guidelines for using thermoplastics as environmentally friendly adhesives and effectively solving indoor pollution problems.

scholarly journals Process modification involving strong-acid step in urea-formaldehyde resin preparation

2020 ◽  
Vol 16 (2) ◽  
pp. 212-217
Author(s):  
Dicky Dermawan ◽  
Lucky William Kusnadi ◽  
Jemmy Lesmana
Keyword(s):  
Urea Formaldehyde ◽  
Gelation Time ◽  
Strong Acid ◽  
Raw Material ◽  
Molar Ratio ◽  
Formaldehyde Resin ◽  
Formaldehyde Concentration ◽  
Formaldehyde Content ◽  
Process Modification ◽  
Uf Resin

Urea-formaldehyde (UF) resin adhesive for wood-based panel industries are commonly manufactured using conventional alkaline-acid process. This paper reports a process modification of a conventional UF resin preparation by incorporating a strong-acid step, involving simultaneous methylolation and condensation reactions at very low pH at the beginning of the processing step. The experiment showed that this additional step should be carried out at short duration and at high enough temperature in order to avoid gelation or separation problems. In order to control temperature rise caused by the exothermic nature of the reactions, the modified process requires a higher initial formaldehyde-to-urea (F/U) molar ratio compared to the original. For the same reason, the first urea should be fed incrementally to ensure high F/U ratio at any time during the strong acid step. Using regular formalin concentration as raw material at the same F/U molar ratio, the modified resin showed lower free formaldehyde content thus have lower reactivity in comparison to those of the original. However, when the same procedure was applied using higher formaldehyde concentration at higher solid content, the produced resin showed comparable free formaldehyde content and shorter gelation time. Application test for making plywood showed that the modified process gave a very significant improvement in both the internal bonding strength and formaldehyde emission.

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