Study on the Bending Mechanical Properties of Bamboo Plywood Used Middle Temperature PF Resine

2011 ◽  
Vol 374-377 ◽  
pp. 1239-1243
Author(s):  
Jan Han ◽  
Yue Zou
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Hot Pressing ◽  
Bending Strength ◽  
Phenol Formaldehyde ◽  
Stress And Strain ◽  
Pressing Temperature ◽  
Study Results ◽  
Load Increase ◽  
Middle Temperature

The bending mechanical properties of bamboo plywood which was glued with phenol formaldehyde (PF) resine were detected and analysised. The study results showed that the differences of the bending strength (MOR)and the elastic modulus(MOE) of bamboo plywood prepared separately within 110-130°C were not large, and MOR and MOE exceeded all the targets ruled by JB/T 156-2004. It was proved that the property of this kind of middle temperature PF resine was very well for using in bamboo plywood. When the load was the same, the differences of the deflection、the stress of the bamboo plywood prepared on the different hot-pressing temperature were very small too, but some differences existed in the those strains，and the strains on the lower sursurface of the boards were larger than those on upper surface. When the load was smaller, The deflection、stress and strain of the boards linearly changed with the load increase, which proved that the bamboo plywood mainly produced elastic deformation under this circumstances.

Fabrication of Carbon Nanotube Reinforced Boron Carbide Composite by Hot-Pressing Following Extrusion Molding

2014 ◽  
Vol 616 ◽  
pp. 27-31 ◽  
Author(s):  
Tomohiro Kobayashi ◽  
Katsumi Yoshida ◽  
Toyohiko Yano
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Elastic Modulus ◽  
Carbon Nanotube ◽  
Boron Carbide ◽  
Vickers Hardness ◽  
Hot Pressing ◽  
Bending Strength ◽  
Extrusion Direction ◽  
Sem Observation

The CNT/B4C composite with Al2O3 additive was fabricated by hot-pressing following extrusion molding of a CNT/B4C paste, and mechanical properties of the obtained composite were investigated. Many CNTs in the composite aligned along the extrusion direction from SEM observation. 3-points bending strength of the composite was slightly lower than that of the monolithic B4C. Elastic modulus and Vickers hardness of the composite drastically decreased with CNT addition. Fracture toughness of the composite was higher than that of the monolithic B4C.

Manufacturer Technology of Dense Chinese Fir Laminated Veneer Lumber (LVL)

2012 ◽  
Vol 542-543 ◽  
pp. 363-366
Author(s):  
Chi Qiang Yao ◽  
Li Yu ◽  
Yan Jun Li ◽  
Shi Ke Xu ◽  
Lan Xing Du
Keyword(s):  
Mechanical Properties ◽  
Hot Pressing ◽  
Phenol Formaldehyde ◽  
Chinese Fir ◽  
Water Soluble ◽  
Technological Parameters ◽  
Pressing Temperature ◽  
Laminated Veneer Lumber ◽  
Pressing Time ◽  
Processing Factors

Dense Chinese Fir LVL was manufactured from Chinese Fir veneer which was impregnated with laboratory prepared water soluble phenol formaldehyde(PF) resin. The influences of various processing factors on properties of dense Chinese Fir LVL were explored. It is showed that the mechanical properties of dense Chinese Fir LVL first increase and then decrease with the increase of drying temperature and hot-pressing time. Plank performance becomes higher with the increase of compressibility and hot-pressing temperature. The optimum technological parameters for LVL process are set.

Fabrication and Mechanical Properties Analysis of Flame-Retardant Fiberboards Made of Abandoned Flax Fibers and Polyurethanes

2012 ◽  
Vol 627 ◽  
pp. 892-895 ◽  
Author(s):  
Li Hua Lv ◽  
Min Zuo ◽  
Chun Yan Wei ◽  
Xiao Wang ◽  
Ke Wang
Keyword(s):  
Mechanical Properties ◽  
Flame Retardant ◽  
Hot Pressing ◽  
Mass Fraction ◽  
Bending Strength ◽  
Range Analysis ◽  
Pressing Temperature ◽  
Limiting Oxygen Index ◽  
Flax Fibers ◽  
Pressing Time

In this paper, abandoned flax fibers were adopted as reinforcing materials, polyurethane particles were adopted as matrix materials. Through blend mastication and hot-pressing methods to exploit flame-retardant fiberboards, which were made of abandoned flax fibers and polyurethanes. This paper explored the mechanical properties and flame-retardant property.Tensile strength, bending strength and impact strength were selected as mechanical properties' test index, limiting oxygen index was selected as flame-retardant property's test index. Abandoned flax fibers mass fraction, hot-pressing temperature, hot-pressing time and flame-retardant mass fraction acted as level of factor. The optimized processing conditions were concluded through orthogonal experiment and the range analysis: abandoned flax fibers mass fraction 45%, hot-pressing temperature 170°C, hot-pressing time 6 min, flame-retardant mass fraction 10%. This paper studied the solution of the abandoned fibers’ reuse. At the same time, it provided theoretical guidance for the further development of flame- retardant polyurethane fiberboard.

Process and Mechanical Properties of Basalt Fiber/Polylactic Acid Composites

2012 ◽  
Vol 193-194 ◽  
pp. 329-332 ◽  
Author(s):  
Li Hua Lv ◽  
Gui Bin Liu ◽  
Dan Zhou
Keyword(s):  
Mechanical Properties ◽  
Polylactic Acid ◽  
Hot Pressing ◽  
Mass Fraction ◽  
Bending Strength ◽  
Matrix Material ◽  
Basalt Fiber ◽  
Pressing Pressure ◽  
Pressing Temperature ◽  
Pressing Time

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.

Investigation of Furfural Formation and Mechanical Properties of Suberinic Acids-Bonded Particleboards Depending on their Preparation Parameters

2021 ◽  
Vol 903 ◽  
pp. 235-240
Author(s):  
Raimonds Makars ◽  
Daniela Godiņa ◽  
Janis Rizhikovs ◽  
Aigars Paze ◽  
Ramunas Tupciauskas ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Hot Pressing ◽  
High Performance ◽  
Bending Strength ◽  
Ph Value ◽  
Raw Material ◽  
Technological Parameters ◽  
Pressing Temperature ◽  
Outer Bark ◽  
Wood Particles

Silver birch (Betula pendula) outer bark suberin can be used as a raw material to make an adhesive for particleboards (PBs). It is a promising formaldehyde-free alternative to traditional synthetic resins. However, the adhesive is acidic, which can catalyse furfural (FUR) formation from xylans in wood particles that are used for the preparation of PBs. FUR being a volatile organic compound can be emitted from the PBs and exposure to it can have harmful effects on humans. In the scope of this study, the effects on technological parameters (wet adhesive pH: 3, 6 and 9), glycerol as an additive to adhesive and hot-pressing temperature (180...230 °C) were investigated on the FUR formation in PBs. The FUR content was determined with high-performance liquid chromatography-ultraviolet spectroscopy system from the extracts of milled PBs. Mechanical properties (modulus of elasticity, bending strength, and thickness swelling) of the PBs were also studied. When using an adhesive with a pH 6 at hot-pressing temperature 230 °C with no glycerol added, it was possible to obtain PBs that satisfied the requirements of EN 312 P2 (boards for interior fitments). The FUR yield of these boards were more than 6 times lower than for the PBs pressed at 230 °C with a wet adhesive pH value 3.

scholarly journals Effects of different pressing conditions on properties of spruce plywoods

2012 ◽  
Vol 52 (No. 6) ◽  
pp. 285-292 ◽  
Author(s):  
P. Král ◽  
J. Hrázský
Keyword(s):  
Mechanical Properties ◽  
Bond Strength ◽  
Shear Test ◽  
Bending Strength ◽  
Phenol Formaldehyde ◽  
Physical And Mechanical Properties ◽  
Institutional Research ◽  
Specific Pressure ◽  
Pressing Temperature ◽  
Nominal Thickness

The paper presents results of an institutional research aimed at assessing the effect of different technological conditions in pressing on physical and mechanical properties of plywood sheets. Spruce plywood sheets of the veneer nominal thickness of 3.0 and 3.5 mm were analyzed. The plywood sheets were produced as five-ply and BAKELITE PF B118 phenol-formaldehyde adhesives were used for there manufacture. In relation to a different pressing temperature 115, 120 and 125°C and a different specific pressure, density, bending strength, MOE in bending and glue-bond strength by a shear test were assessed. The determined values of properties were statistically tested.

A Study on Tensile Mechanical Properties of Bamboo Plywood

2011 ◽  
Vol 291-294 ◽  
pp. 1009-1014 ◽  
Author(s):  
Jian Han ◽  
Xi Tao Gao
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Tensile Stress ◽  
Elastic Deformation ◽  
Modulus Of Elasticity ◽  
Tensile Deformation ◽  
Tensile Modulus ◽  
Stress And Strain ◽  
Load Increase ◽  
Tensile Elastic Modulus

The tensile mechanical properties of bamboo mat and curtain plywood（for short bamboo plywood）were studied through “electrometric method”. It was proved that in the range of elastic deformation，the Poisson′s ratio and the elastic modulus of the bamboo plywood were not constant. The Poisson′s ratio of the bamboo plywood decreased nonlinearly with the load increase that Poisson′s ratio decreased markedly when the load was less than 1kN，and decreased gently when more than 1kN.The tensile elastic modulus of the bamboo plywood also increased nonlinearly with the load increase that the tensile modulus of elasticity increased drastically when the load was less than 800N，and increased less when exceeded 800N. In the process of loading，the tensile deformation、the tensile stress and strain all increased linearly with the load increase，and the tensile stress and strain both were linearly relevant to tensile deformation.

Mechanical Properties of Secondary Wall and Compound Corner Middle Lamella near the Phenol-Formaldehyde (PF) Adhesive Bond Line Measured by Nanoindentation

2011 ◽  
Vol 236-238 ◽  
pp. 1746-1751 ◽  
Author(s):  
Kun Liang ◽  
Guan Ben Du ◽  
Omid Hosseinaei ◽  
Si Qun Wang ◽  
Hui Wang
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Secondary Wall ◽  
Phenol Formaldehyde ◽  
Middle Lamella ◽  
Adhesive Bond ◽  
Cellular Level ◽  
Bond Line ◽  
Line Region ◽  
Penetration Behavior

To find out the penetration of PF into the wood cell wall and its effects onthe mechanical properties in the cellular level, the elastic modulus and hardness of secondary wall (S2layer) and compound corner middle lamella (CCML) near PF bond line region were determined by nanoindentation. Compare to the reference cell walls (unaffected by PF), PF penetration into the wood tissues showed improved elastic modulus and hardness. And the mechanical properties decreased slowly with the increasing the distance from the bond line, which are attributed to the effects of PF penetration into S2layer and CCML. The reduced elastic modulus variations were from18.8 to 14.4 GPa for S2layer, and from10.1 to 7.65 GPa for CCML. The hardness was from 0.67 to 0.52 GPa for S2layer, and from 0.65 to 0.52 GPa for CCML. In each test viewpoint place, the average hardness of CCML was almost as high as that of S2layer, but the reduced elastic modulus was about 50% less than that of S2layer. But the increase ratio of mechanical properties was close. All the results showed PF penetrates into the CCML. The penetration behavior and penetration depth from bond line were similar in both S2layer and CCML.

scholarly journals Fabrication of (SiC-AlN)/ZrB2 Composite with Nano-Micron Hybrid Microstructure via PCS-Derived Ceramics Route

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 334
Author(s):  
Aidong Xia ◽  
Jie Yin ◽  
Xiao Chen ◽  
Zhengren Huang ◽  
Xuejian Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Flexural Strength ◽  
Hot Pressing ◽  
Raw Materials ◽  
Secondary Phase ◽  
Pressing Temperature ◽  
Xrd Pattern ◽  
Mean Grain Size ◽  
The Mean

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.

scholarly journals Environmentally-Friendly High-Density Polyethylene-Bonded Plywood Panels

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1166 ◽  
Author(s):  
Pavlo Bekhta ◽  
Ján Sedliačik
Keyword(s):  
Mechanical Properties ◽  
Hot Pressing ◽  
High Density Polyethylene ◽  
Phenol Formaldehyde ◽  
Urea Formaldehyde ◽  
Physical And Mechanical Properties ◽  
Core Layer ◽  
High Density ◽  
Pressing Pressure ◽  
Pressing Time

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.

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