The influence of defibration pressure and fibres drying parameters on the properties of HDF made with recovered fibres

2020 ◽  
Vol 111 ◽  
pp. 143-159
Author(s):  
Conrad M. Sala ◽  
Grzegorz Kowaluk

Defibration pressure and fibres drying parameters influence on the HDF properties made with recovered fibres. The objective of this study was to investigate the defibration pressure and fibres drying process parameters (influence on the mechanical, physical properties and on formaldehyde content (FC) of ultrathin (2.5 mm) industrial high-density fibreboards (HDF) produced with 5% of recovered HDF (rHDF) addition. For this investigation the fibres were produced in industrial defibrator under four different set points: 0.65 MPa (V1), 0.90 MPa (V2), 1.00 MPa (V3) and 1.06 MPa (V4), dried in industrial two stage dryer with four different dryer inlet temperatures set points: 100°C (V00), 111°C (V11), 122°C (V22) and 133°C (V33). The results indicated that pressure is a significant factor and affects for all HDF properties. Too low defibrator pressure negatively influences HDF mechanical and physical properties as well as FC (high level). Regarding fibre drying temperature influence on HDF properties, no straight correlation was found. Linear negative correlation was found for modulus of rupture – 10% decrease comparing V00 to V33, internal bond – 23% decrease comparing V00 to V22 and surface soundness – also 23% decrease comparing V00 to V33.

2021 ◽  
Vol 115 ◽  
pp. 55-62
Author(s):  
Stella Rzyska-Pruchnik ◽  
Grzegorz Kowaluk

The influence of particleboard resination on their internal bond strength. The aim of the project was to investigate the main mechanical and physical properties of particleboards, especially focused on internal bond, in terms of their resination. For the tests, the particleboards have been produced in laboratory conditions with the following glue content: 7, 10, 15, 30 and 50%. Particular attention was paid for examining the mechanical property – tensile strength perpendicular to surfaces (Internal Bond – IB). In addition, there were investigated modulus of elasticity (MOE), modulus of rupture (MOR) density and density profile. In the light of above mentioned tests, there is no positive effect of improvement of tested parameters when raise resination over 30% when producing particleboards. With the resination increase from 7 to 50% a significant change (densification) of panels’ structure, as well as differences between face and core layers density have been found.


Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2632 ◽  
Author(s):  
Marius Cătălin Barbu ◽  
Yasmin Lohninger ◽  
Simon Hofmann ◽  
Günther Kain ◽  
Alexander Petutschnigg ◽  
...  

The aim of this study is to investigate the formaldehyde content and emissions of bark-based insulation panels bonded with three types of adhesives: urea formaldehyde, melamine urea-formaldehyde, and tannin-based adhesives. These panels were produced at two levels of density—300 and 500 kg/m3—and a thickness of 20 mm, and the influence of the adhesive amount and type on the formaldehyde emissions and content was measured. Other mechanical and physical properties such as modulus of rupture, modulus of elasticity, internal bond, and dimensional stability were also scrutinized. With one exception, all the panels belonged to the super E0 classification for free formaldehyde content (perforator value ≤1.5 mg/100 g oven dry mass of panels). The measurements using the desiccator method for formaldehyde emissions assigned all the testing specimens in the F **** category for low-emission panels according to the Japanese International Standards.


BioResources ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. 6984-6992
Author(s):  
Ali Hassanpoor Tichi

Effects of two widely available and underutilized lignocellulosic materials on the mechanical and physical properties of particleboards were investigated in this work. The ratio of mixtures lignocellulosic flakes at four levels (100% aspen wood), (50% aspen wood: 25% citrus: 25% old railroad ties), (50% aspen wood: 50% citrus), and (50% aspen wood: 50% old railroad ties), and the percentage of resin in two levels (8 and 12%) were considered as variable factors. The 100% aspen wood (Populus tremula) was mixed as a control board (100% aspen wood). Then the mechanical and physical properties of the samples including modulus of rupture, modulus of elasticity, internal bond, water absorption, and thickness swelling after 2 h and 24 h of immersion (EN 310-319) and fire resistance (ISO 11925-2) were measured. The results showed that with increasing poplar wood in mixtures, modulus of rupture, modulus of elasticity, internal bond increased, while water absorption and thickness swelling decreased. Also, in comparison with the control boards, the boards that were made by mixing 50% poplar and 50% citrus branches with 12% glue had the highest mechanical strength. The results also showed that increasing the amount of old railroad ties chips in mixing caused a significant decrease in the fire retardancy of the boards.


Holzforschung ◽  
1999 ◽  
Vol 53 (2) ◽  
pp. 215-222 ◽  
Author(s):  
Todd F. Shupe ◽  
Chung Y. Hse ◽  
Elvin T. Choong ◽  
Leslie H. Groom

Summary The objective of this study was to determine the effect of five different silvicultural strategies and wood type on mechanical and physical properties of loblolly pine (Pinus taeda L.) particleboard and fiberboard. The furnish was prepared in an unconventional manner from innerwood and outerwood veneer for each stand. Modulus of rupture (MOR) differences between the stands were insignificant for particleboard. Some significant modulus of elastisity (MOE) differences existed between the stands for particleboard and fiberboard. Differences between the wood types were minimal for each stand. Innerwood yielded higher mean MOR, MOE, and internal bond (IB) values than outerwood for most of the stands. The differences between the stand and wood types for 2 and 24 h thickness swell and 2 and 24h water adsorption were very minimal. This research has shown that innerwood can produce particleboard and fiberboard panels with very comparable mechanical and physical properties to outerwood. The effect of the silvicultural strategy (i. e., stand) was minimal for most properties.


2007 ◽  
Vol 18-19 ◽  
pp. 43-48 ◽  
Author(s):  
J.O. Osarenmwinda ◽  
J.C. Nwachukwu

The purpose of this study was to determine the effect of particle size on the mechanical properties (Modulus of Elasticity, Modulus of Rupture, and Internal Bond) and physical properties (thickness swelling and water absorption) of rice husk particleboard. The particle sizes used were 1.0mm, 1.18mm, 2mm, 2.36mm and 2.80mm. Each was mixed with a constant resin (urea formaldehyde) concentration of 20% of oven dry weight of rice husk particles. The results showed that as the particle size increased, the particleboard’s mechanical and physical properties decreased. For example, the modulus of elasticity, modulus of rupture, internal bond, thickness swelling and water absorption for 1.0mm particle size particleboard were 1590N/mm2, 11.11N/mm2, 0.28N/mm2,10.90% and 38.53% respectively, while for 2.8mm particle size they were 1958N/mm2,14.2N/mm2, 0.44N/mm2, 11.51% and 47.21% respectively. Overall results showed that particleboard made from rice husk exceed the EN standard for modulus of elasticity, modulus of rupture, internal bond. However, thickness swelling values were poor. Hence, the smaller the particle size the better the properties of the particleboard.


BioResources ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 4171-4199
Author(s):  
Eva Oktoberyani Christy ◽  
Soemarno ◽  
Sumardi Hadi Sumarlan ◽  
Agoes Soehardjono

This study investigated the effects of the pressing temperature on the mechanical and physical properties of binderless bark particleboard made from Gelam bark waste and the improvement of those properties. In addition, the thermal insulation properties of the particleboard were determined. Four different temperatures (140 °C, 160 °C, 180 °C, and 200 °C) were used to make single-layer binderless bark particleboard with a target density of less than or equal to 0.59 g/cm3. Results revealed that the pressing temperature affected the mechanical properties (modulus of rupture, modulus of elasticity, and tensile strength perpendicular to panel surface), which increased as the temperature increased, and the physical properties (thickness swelling and water absorption), which decreased as the temperature increased. Based on the Tukey test, increasing the temperature from 180 to 200 °C did not significantly affect the mechanical or physical properties, except for the tensile strength perpendicular to panel surface. None of the mechanical properties met SNI standard 03-2105-2006 (2006); however, the 12% maximum thickness swelling requirement was met for binderless bark particleboard hot-pressed at 200 °C. Binderless bark particleboard hot-pressed at 200 °C had high water resistance, regardless of its low strength, and a thermal conductivity value of 0.14 W/m∙K.


Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4260
Author(s):  
Ziling Shen ◽  
Zhi Ye ◽  
Kailin Li ◽  
Chusheng Qi

Wood–plastic composites (WPC) with good mechanical and physical properties are desirable products for manufacturers and customers, and interfacial bond strength is one of the most critical factors affecting WPC performance. To verify that a higher interfacial bond strength between wood and thermoplastics improves WPC performance, wood veneer–thermoplastic composites (VPC) and oriented strand–thermoplastic composites (OSPC) were fabricated using hot pressing. The effects of the coupling agent (KH550 or MDI) and the thermoplastic (LDPE, HDPE, PP, or PVC) on the interfacial bond strength of VPC, and the mechanical and physical properties of OSPC, were investigated. The results showed that coupling agents KH550 and MDI improved the interfacial bond strength between wood and thermoplastics under dry conditions. MDI was better than KH550 at improving the interfacial bond strength and the mechanical properties of OSPC. Better interfacial bonding between plastic and wood improved the OSPC performance. The OSPC fabricated using PVC film as the thermoplastic and MDI as the coupling agent displayed the highest mechanical properties, with a modulus of rupture of 91.9 MPa, a modulus of elasticity of 10.9 GPa, and a thickness swelling of 2.4%. PVC and MDI are recommended to fabricate WPCs with desirable performance for general applications.


2021 ◽  
Vol 71 (3) ◽  
pp. 275-282
Author(s):  
Yoichi Kojima ◽  
Tetsuya Makino ◽  
Kazuaki Ota ◽  
Kazushige Murayama ◽  
Hikaru Kobori ◽  
...  

Abstract The objective of this study was to investigate the lab-scale manufacturing process of insulation fiberboard (IFB) with cellulose nanofibers (CNFs) and evaluate the effects of CNFs on the mechanical and physical properties of the IFB. Because the fabricated IFBs with CNFs had a homogeneous appearance, it was assumed that CNFs can be easily dispersed within IFB by adding them during the mixing stage of the wet process of wood-based board production. The results for the IFBs with CNFs revealed that the density and bending properties increased, while the thickness decreased with an increase in the CNF addition ratio. Furthermore, after the water absorption test, the weight change rates of the IFBs decreased, and the thickness swelling rates increased. Although the size of the specimens was different from the size in JIS A 5905 (Japan Standards Association 2014), the modulus of rupture (MOR) values of IFBs with a target density more than or equal to 0.20 g/cm3 were higher than the value of A-class IFB in the standard for all CNF addition ratios. In addition, lower thermal conductivity may be realized under similar MOR values by adding CNFs to IFB. On the other hand, to produce CNF-reinforced IFBs with target density/thickness, it is necessary to develop a method for decreasing the cohesive force derived from CNF aggregation and the compressive force originating from the water surface tension caused by the high water retention of CNFs.


2007 ◽  
Vol 37 (5) ◽  
pp. 866-873 ◽  
Author(s):  
Jun Li Shi ◽  
Bernard Riedl ◽  
James Deng ◽  
Alain Cloutier ◽  
S. Y. Zhang

Mechanical and physical properties of medium-density fibreboard (MDF) panels made from black spruce ( Picea mariana (Mill.) BSP) top, middle, and butt logs were studied. The analysis of variance and analysis of covariance were both performed to examine the impact of log position in the tree on panel modulus of rupture (MOR), modulus of elasticity (MOE), internal bond (IB), linear expansion (LE), thickness swell (TS), and water absorption. Results indicate that MOE and IB strength of MDF panels made from top and middle logs were significantly superior to those of panels made from butt logs; however, there was no significant difference in MOE and IB between panels made from top and middle logs. Water absorptions of top and middle log panels were significantly lower than that of panels made from butt logs, and the difference in water absorption between panels made from top and middle logs was not significant. TS of top log panels was the smallest among the panels from the three log positions in the tree and was significantly different from those of middle and butt log panels. TS of butt log panels was the highest, which was significantly different from that of top and middle log panels. The differences in LE among the panels made from top, middle, and butt logs were not significant. The comparison of MOR of top, middle, and butt log panels was dependent on panel density because of the interactions among the three groups. Top and middle log panels showed superior properties, because the thinner cell walls of fibres from top and middle logs resulted in an increased compaction ratio compared with the butt log panels. Panel density affected both panel MOR and MOE considerably; however, its impact on IB, LE, TS, and water absorption was not significant in this study. The equations describing the linear relationships between MOR, MOE, and panel density were developed.


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