scholarly journals EFFECTS OF HOT PRESSING PARAMETERS ON THE PROPERTIES OF HARDBOARDS PRODUCED FROM MIXED HARDWOOD TREE SPECIES

Wood Research ◽  
2021 ◽  
Vol 66 (3) ◽  
pp. 437-448
Author(s):  
Petar Antov ◽  
Viktor Savov ◽  
Nikolay Neykov ◽  
Ľuboš Krišťák

In this work, wet-process fibreboards (hardboards) were produced in the laboratory using industrial wood fibres of the species European beech (Fagus sylvatica L.) and Turkey oak (Quercus cerris L.) at the total volume of 40%, and white poplar (Populus alba L.) at 60% volume. The effects of hot pressing pressure (varied from 3.3 MPa to 5.3 MPa) and pressing time (from 255 s to 355 s) on the physical and mechanical properties of hardboards were investigated and optimal values of the parameters for fulfilling the European standard requirements were determined. It was concluded that hardboards with acceptable physical and mechanical properties may be produced from 60% poplar wood waste and residues, combined with 40% hardwood raw materials (beech and oak) by regulating the hot pressing regime only, i.e. pressure and pressing time. The following minimum parameters for producing hardboards from mixed hardwood tree species were determined: a pressure of 4.6 MPa and a pressing time of 280 s.

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1166 ◽  
Author(s):  
Pavlo Bekhta ◽  
Ján Sedliačik

Thermoplastic films exhibit good potential to be used as adhesives for the production of veneer-based composites. This work presents the first effort to develop and evaluate composites based on alder veneers and high-density polyethylene (HDPE) film. The effects of hot-pressing temperature (140, 160, and 180 °C), hot-pressing pressure (0.8, 1.2, and 1.6 MPa), hot-pressing time (1, 2, 3, and 5 min), and type of adhesives on the physical and mechanical properties of alder plywood panels were investigated. The effects of these variables on the core-layer temperature during the hot pressing of multiplywood panels using various adhesives were also studied. Three types of adhesives were used: urea–formaldehyde (UF), phenol–formaldehyde (PF), and HDPE film. UF and PF adhesives were used for the comparison. The findings of this work indicate that formaldehyde-free HDPE film adhesive gave values of mechanical properties of alder plywood panels that are comparable to those obtained with traditional UF and PF adhesives, even though the adhesive dosage and pressing pressure were lower than when UF and PF adhesives were used. The obtained bonding strength values of HDPE-bonded alder plywood panels ranged from 0.74 to 2.38 MPa and met the European Standard EN 314-2 for Class 1 plywood. The optimum conditions for the bonding of HDPE plywood were 160 °C, 0.8 MPa, and 3 min.


2012 ◽  
Vol 503-504 ◽  
pp. 74-77
Author(s):  
Nan Hu ◽  
Xian Jun Li ◽  
Yi Qiang Wu ◽  
Xin Gong Li ◽  
Zhi Cheng Xue

In this paper, the new bamboo-based consolidated composite floors were fabricated with thin bamboo veneers which used as decoration layers, wear resistant layers, high density fiberboards and equilibrium layers through assembling and scuffing. The effect rules of the composite floor on properties were preliminarily studied by three factors: hot-pressing temperature, pressure and time. The results showed that the wear resistance and surface bond strength of the thin bamboo veneer consolidated composite floor significantly increased with the rise of hot-pressing temperature. In the scope of resources, the effect of hot-pressing pressure and time on properties of the floor is not significant. The optimizing technology is hot-pressing temperature 170°C, pressure 3MPa and time 40s/mm in this study. The thin bamboo veneer consolidated composite floor is an excellent floor decorative material, which has good physical and mechanical properties.


2018 ◽  
Vol 8 (1) ◽  
pp. 132-138
Author(s):  
Виктор Бурындин ◽  
Viktor Buryndin ◽  
Лариса Бельчинская ◽  
Larisa Belchinskaya ◽  
Андрей Савиновских ◽  
...  

The possibility of obtaining wood and plant plastics without a binder (WP-WB) in the presence of a catalyst of man-ganese-containing sodium vanadomolybdophosphate has been investigated. The use of this catalyst makes it possible to reduce the temperature of hot pressing in closed molds from 1,800°C to 1,600°C. The fractional composition of the initial press raw material influences physical and mechanical properties of WP-WB. Higher values of the plastic properties are obtained by using a 0.7 mm fraction, which is associated with an increased specific surface area of the particles compared to 1.3 mm particles. The results has showed that the samples obtained by using the catalyst have increase in strength properties (flexural strength, flexural modulus, hardness) at lower pressing temperature, but reduction of water resistance performance has been observed . This is explained by the increase in the content of functional groups when using a catalyst. The process of obtaining plastic can be broken down into two successive stages: the first is hydrothermal destruction of lignin-carbohydrate complex (initial moisture of the press raw material is 12%, the temperature of hot pressing in closed molds is 160 ... .180 ° C) and partial chemical activation of lignin as a result of hydrogen peroxide and catalyst application; the second stage - formation of plastic with the formation of a network structure due to the formed functional groups. It is established that the values of physical and mechanical properties of WP-WB are higher than those of plastic obtained on the basis of plant raw materials (PP-WB). This can be explained by the fact that lignin of coniferous species has the guaiacylpropane structure, while plant raw material has a hydroxyphenylpropane structure


BioResources ◽  
2019 ◽  
Vol 14 (2) ◽  
pp. 3746-3757
Author(s):  
Marilia da Silva Bertolini ◽  
César Augusto Galvão de Morais ◽  
André Luis Christoforo ◽  
Stelamaris Rolla Bertoli ◽  
Wilson Nunes dos Santos ◽  
...  

The development of materials that offer environmental comfort inside buildings, through adequate thermal and acoustic behavior, has been as relevant as the search for raw materials of renewable origin. In this context, this study produced and characterized panels made with Pinus sp. waste materials, which were treated with a copper chrome boric oxide preservative and a castor-oil based polyurethane resin. The physical and mechanical properties of the panels were evaluated according to the ABNT NBR 14810 standard (2013). The panel porosity was investigated by scanning electron microscopy (SEM) and mercury intrusion porosimetry techniques. The sound absorption was analyzed by a reverberation chamber and thermal conductivity by the modified fractionated column method. Samples with a higher pressing pressure (4 MPa) during the manufacturing presented lower thickness swelling and higher mechanical properties in static bending. Panels made with a lower press pressure (2.5 MPa) resulted in a higher porosity volume (55.7%). The more highly porous panels were more acoustically efficient, with a sound absorption coefficient close to 0.8 at 3.2 kHz, and they had a better thermal conductivity performance.The potential of these panels for application where sound absorption and thermal insulation are prioritized is thus observed.


2011 ◽  
Vol 80-81 ◽  
pp. 207-212 ◽  
Author(s):  
Jin Wang ◽  
Li Liu ◽  
Chun De Jin

The different age pleioblastus amarus particle were taken as the raw materials, and the wet-process bamboo powder-boards were made from the laccase-treated powder by hot pressing. The raw material chemical constituents were analyzed. The reactive oxygen species free radicals produced from the laccase-treated bamboo were detected by electron spin resonance. The physical and mechanical properties of the bamboo particleboards were measured. In order to provide some theoretical basis for producing bamboo particleboard by laccase activation, the relations between physical and mechanical properties of bamboo particle boards and chemical constituents, the reactive oxygen species free radicals were researched.


2012 ◽  
Vol 193-194 ◽  
pp. 329-332 ◽  
Author(s):  
Li Hua Lv ◽  
Gui Bin Liu ◽  
Dan Zhou

In this paper, the basalt fiber/polylactic acid composites were prepared by laying-up hot-pressing process, using PLA sheet as the matrix material and basalt fiber fabrics as the reinforced material, besides, the mechanical properties were studied and the parameters of hot-pressing were optimized. PLA mass fraction, heat pressing temperature, heat pressing pressure and heat pressing time were selected as the four main influence factors and tensile strength and bending strength were taken as the test indexes, the best processing conditions: PLA mass fraction 63%, Heat pressing temperature 195 °C, Heat pressing pressure 7MPa, Heat pressing time 10min were optimized through orthogonal experiment and range analysis. The significance of the study was providing theoretical guidance for the further development of high-performance basalt fiber composites.


2019 ◽  
Vol 51 (2) ◽  
pp. 132-143
Author(s):  
Andi Sri Rahayu Diza Lestari ◽  
Yusuf Sudo Hadi ◽  
Dede Hermawan ◽  
Adi Santoso ◽  
Antonio Pizzi

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 334
Author(s):  
Aidong Xia ◽  
Jie Yin ◽  
Xiao Chen ◽  
Zhengren Huang ◽  
Xuejian Liu ◽  
...  

In this work, a (SiC-AlN)/ZrB2 composite with outstanding mechanical properties was prepared by using polymer-derived ceramics (PDCs) and hot-pressing technique. Flexural strength reached up to 460 ± 41 MPa, while AlN and ZrB2 contents were 10 wt%, and 15 wt%, respectively, under a hot-pressing temperature of 2000 °C. XRD pattern-evidenced SiC generated by pyrolysis of polycarbosilane (PCS) was mainly composed by 2H-SiC and 4H-SiC, both belonging to α-SiC. Micron-level ZrB2 secondary phase was observed inside the (SiC-AlN)/ZrB2 composite, while the mean grain size (MGS) of SiC-AlN matrix was approximately 97 nm. This unique nano-micron hybrid microstructure enhanced the mechanical properties. The present investigation provided a feasible tactic for strengthening ceramics from PDCs raw materials.


2011 ◽  
Vol 43 (3) ◽  
pp. 289-294 ◽  
Author(s):  
J. Zhu ◽  
L. Ye ◽  
F. Wang

A Ti3AlC2/Al2O3 nanocomposite was synthesized using Ti, Al, C and TiO2 as raw materials by a novel combination of high-energy milling and hot pressing. The reaction path of the 3Ti-8C-16Al-9TiO2 mixture of powders was investigated, and the results show that the transitional phases TiC, TixAly and Al2O3 are formed in high-energy milling first, and then TixAly is transformed to the TiAl phase during the hot pressing. Finally, a reaction between TiC and TiAl occurs to produce Ti3AlC2 and the nanosized Ti3AlC2/Al2O3 composite is synthesized. The Ti3AlC2/Al2O3 composite possessed a good combination of mechanical properties with a hardness of 6.0 GPa, a flexural strength of 600 MPa, and a fracture toughness (K1C) of 5.8 MPa?m1/2. The strengthening and toughening mechanisms were also discussed.


2019 ◽  
Vol 7 (2) ◽  
Author(s):  
Dendi Prayoga ◽  
. Dirhamsyah ◽  
. Nurhaida

This research aimed to examine the physical and mechanical properties of particle boards based on the composition of raw materials and adhesive content and know the treatment of the composition of raw materials and the best adhesive content and meet the standard JIS A 5908-2003. The research was conducted at Wood Workshop Laboratory, Wood Processing Laboratory Faculty of Forestry,Tanjungpura University and Laboratory of PT. Duta Pertiwi Nusantara Pontianak. The adhesive used is Urea Formaldehyde with 52% Solid Content. Comparison of the composition of rice husks and sengon varies namely rice husk 50%: sengon 50%, rice husk 60%: sengon 40% and rice husk 70%: sengon 30%  and variations in the levels of UF adhesives, namely 14% and 16%, with target density 0,7 gr/cm3. The particleboard was 30 cm x 30 cm x 1 cm Pressing at temperature 140oC for 8 minutes, with  pressure of 25 kg/cm2. The research results of the study of density and moisture content meet the standards JIS A 5908-2003. The best particle values of rice husk and sengon  with composition a ratio of  rice husk 50%: sengon 50% , 16% adhesive content  16%, with density value of  0,7072 gr/cm3, moisture content 9,1949 %, thick development 12,3210 %, water absorption 68,8270 %, MOE 12110,7273 kg/cm2, MOR 161,0025 kg/cm2, firmness sticky 1,9320 kg/cm2, screw holding strength 62,3124 kg.Keywords : adhesive, composition, particle board, rice husk, sengon


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