scholarly journals Physico-mechanical and joint performance of bamboo veneer products manufactured by mould pressing

BioResources ◽  
2019 ◽  
Vol 14 (2) ◽  
pp. 3823-3832
Author(s):  
Wenfu Zhang ◽  
Shaohua Gu ◽  
Cuicui Wang ◽  
Haitao Cheng ◽  
Ge Wang

Bamboo can be processed into engineering materials with excellent properties by reasonable processing methods. In this study, the performance of mould-pressed bamboo (MBP) veneer products was examined. The physical mechanical properties and connection properties of MPB were tested, and the application performance of the MPB was analyzed. The results show that MPB has a comprehensive property of high internal bonding and good dimensional stability, and its density and mechanical properties are similar to those of wood dimensional stock. The overall bending strength, bending modulus, and compression strength of MPB were 29.0 MPa, 6.83 GPa, and 15.6 MPa, respectively. While the overall carrying capacity was relatively low, the connection performance of BPM was good. Thus, it can be used as a connector or substructure.

2014 ◽  
Vol 1025-1026 ◽  
pp. 246-250 ◽  
Author(s):  
Bruno Santos Ferreira ◽  
Cristiane Inácio de Campos ◽  
Marcos Tadeu Tibúrcio Gonçalves

Alternative raw materials have been studied for the total or partial replacement of wood in wood panels, in order to decrease the use of wood and to recovery waste. The present study tested the influence on the physico-mechanical properties of the panels produced with particles of Eucalyptus saligna and macadamia nutshell. For this were produced panels in proportions of 0%, 30%, 60% and 100% with respect to the macadamia nutshells. With the obtained results it was noticed that the increasing of the nutshell proportion led to a decrease in the dimensional stability, internal bonding and bending strength. These results were primarily due to the geometry of the particles of macadamia nutshell, besides being thicker, not allowing a good interaction between them and the adhesive, they were shorter, reducing the bending strength.


2019 ◽  
Vol 27 (4(136)) ◽  
pp. 88-93
Author(s):  
K.Z.M. Abdul Motaleb ◽  
Md Shariful Islam ◽  
Rimvydas Milašius

Two types of composites:(1) pineapple fabric reinforced polyester resin (Pineapple/PR) and (2) jute fabric reinforced polyester resin (Jute/PR) were prepared and the mechanical properties investigated for various gamma radiation doses ranging from 100-500 krad. Properties like tensile strength, Young’s modulus, elongation-at-break, bending strength, bending modulus and impact strength were increased significantly by 19%, 32%, 45%, 32%, 47% and 20%, respectively, at a dose of 300 krad for Pineapple/PR, and by 47%, 49%, 42%, 45%, 52% and 65%, respectively, at a dose of 200 krad for the Jute/PR composite in comparison to the non-irradiated composite. Gamma radiation improved the mechanical properties, but overdoses of radiation even caused a reduction in them.


2019 ◽  
Vol 24 ◽  
pp. 1-7
Author(s):  
Md. Naimul Islam ◽  
Harun Ar-Rashid ◽  
Farhana Islam ◽  
Nanda Karmaker ◽  
Farjana A. Koly ◽  
...  

E-glass fiber mat reinforced Unsaturated Polyester Resin (UPR)-based composites were fabricated by conventional hand lay-up technique. The fiber content was varied from 5 to 50% by weight. Mechanical properties (tensile and bending) of the fabricated composites were investigated. The tensile strength (TS) of the 5% and 50% fiber reinforced composites was 32 MPa and 72 MPa, respectively. Similarly, tensile modulus, bending strength and bending modulus of the composites were increased by the increase of fiber loading. Interfacial properties of the composites were investigated by scanning electron microscopy (SEM) and the results revealed that the interfacial bond between fiber and matrix was excellent. Keywords: Unsaturated Polyester Resin, Mechanical Properties, E-glass Fibers, Composites, Polymer.


Forests ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 920 ◽  
Author(s):  
Lin Yang ◽  
Hong-Hai Liu

Wood is an environmentally friendly material, but some natural properties limit its wide application. To study the effect of a combination of heat treatment (HT) and wax impregnation (WI) on wood hygroscopicity, dimensional stability, and mechanical properties, samples of Pterocarpus macrocarpus Kurz wood were subjected to HT at a moderate temperature of 120 °C and a high temperature of 180 °C, for a 4 h duration. Subsequently, half of the 120 °C HT samples were treated with WI at 90 °C. The results showed that 180 °C HT and WI decreased the capacity of adsorption and liquid water uptake and swelled the wood significantly, while WI had the biggest reduction. The effect of 120 °C HT was significant only on decreasing the capacity of adsorption and the swelling of liquid water uptake. The bending strength (MOR) of wood decreased only after 180 °C HT, and 120 °C/4h HT and WI had no significant influence on MOR. The bending stiffness (MOE) increased significantly after 180 °C HT and WI, while 120 °C/4h HT had no significant influence on MOE. Therefore, the combination of moderate-temperature HT can act synergistically in the improvement of certain aspects of wood properties such as capacity of water adsorption and liquid water uptake. WI effectively improved wood hygroscopicity, dimensional stability, and mechanical properties.


2017 ◽  
Vol 726 ◽  
pp. 3-7
Author(s):  
Zhao Liu ◽  
Chun Lin Hu ◽  
Yi Wang Bao

To explore the effects of preparation process on the mechanical properties of fiber reinforced tubes in radial direction, the closed ring method was applied to assess the elastic modulus and bending strength of GFRP and CFRP prepared by winding method and pultrusion method, respectively. The results indicate that there are two obvious differences between the winding tube and the pultrusion tube: i) the elastic modulus and bending strength of the winding tube for two materials are larger than that of the pultrusion tube. It should be attributed to the position of materials under stress: the former is the fibers while the latter is the matrix; ii) the failure mode for the winding tube is brittle fracture while elastic-plastic fracture is for the pultrusion tube. Compared with other experimental methods, the results of the closed ring method are accurate and reliable, which is demonstrated to be a potential method to evaluate the mechanical properties of fiber tubes in radial direction rapidly and conveniently.


2019 ◽  
Vol 70 (3) ◽  
pp. 221-228
Author(s):  
Abdullah Istek ◽  
Ismail Ozlusoylu

In this study, the effect of mat moisture content on the physical and mechanical properties of particleboard was investigated. The experimental boards were produced by using 40 % softwood, 45 % hardwood chips, and 15 % sawdust. The formaldehyde resin/adhesive was used in three-layers (bottom-top layer 12 %, core layer 8 %). Multi-opening press was used during manufacturing the experimental particleboards. The physical and mechanical properties of boards obtained were identified according to the TS-EN standards. The optimum core layer moisture content was determined as 6 % and 7 % according to the results, whereas the moisture content of bottom and top layers was 14 %. Under these moisture content conditions, the bending strength was found to be 13.3 N/mm², the modulus of elasticity in bending 2466 N/mm², and internal bonding strength 0.44 N/mm². The optimum bottom-top layer moisture content was determined to be between 13 % and 15 % and 6.5 % for the core layer.


Author(s):  
A.N.M. Masudur Rahman ◽  
Shah Alimuzzaman ◽  
Ruhul Amin Khan ◽  
Md. Ershad Khan ◽  
Sheikh Nazmul Hoque

In this study, an attempt has been taken to manufacture okra fiber (OF) composites with varying the fiber content ranging from 25-65% on total weight of the composites and polypropylene (PP) was preferred as matrix material. To fabricate the composites untreated and mercerized fibers were selected. A systematic study was done to observe the mechanical behaviors of the composites such as tensile, impact and bending properties. It was found that treated (mercerized) fiber composites exhibited improved mechanical properties than that of untreated fiber composites. Maximum tensile strength (TS) and bending strength (BS) was examined 38.5 MPa and 72.5 MPa respectively, whereas the highest tensile modulus (TM) and bending modulus (BM) was observed 675 MPa and 5.4 GPa respectively. The optimum impact strength (IS) and hardness value was found to be 22.87 KJ/m2 and 97 (Shore-A) for mercerized fiber composites containing 45% fiber. The composite samples were exposed to different intensities of γ radiation (2.5 kGy–10.0 kGy) and found significant improvement in the mechanical properties up to 5.0 kGy dose. Water absorption, degradation properties due to heat and soil medium of the composites were also performed. The interfacial property was examined by Microscopic Projector and Scanning Electron Microscope (SEM) and found that the interfacial bonding between matrix material and fiber was enhanced due to the treatment of fibers which authenticate the found mechanical characteristics of the composites.


BioResources ◽  
2017 ◽  
Vol 12 (4) ◽  
pp. 9212-9226
Author(s):  
Qilan Fu ◽  
Alain Cloutier ◽  
Aziz Laghdir

Effects of heat and steam were investigated relative to the mechanical properties and dimensional stability of thermo-hygromechanically-densified sugar maple wood (Acer saccharum Marsh.). The densification process was performed at four temperatures (180 °C, 190 °C, 200 °C, and 210 °C) with and without steam. The hardness, bending strength, bending stiffness, and compression set recovery of the control and densified samples were determined. The effects of heat and steam on the density profile of the samples across thickness were also investigated. The results suggested that the effects of steam on the mechanical properties and dimensional stability of sugar maple wood were more important than that of heat’s influence. Compared to the samples densified without steam, the samples densified with steam showed higher values for hardness, bending strength, bending stiffness, compression set, and density, but much lower compression set recovery when treatment temperature was below 200 °C. High temperature combined with steam contributed to decreased compression set recovery. The lowest compression set recovery was obtained after the first swelling/drying cycle for all of the treatments. A higher weight loss occurred at 210 °C, which resulted in a noticeable decrease of wood density.


2007 ◽  
Vol 546-549 ◽  
pp. 1521-1524
Author(s):  
Xiao Hu Zhang ◽  
He Jun Li ◽  
Zhi Biao Hao ◽  
Hong Cui

The influence of needling parameters on mechanical properties of carbon-carbon (C-C)composites reinforced by needled carbon cloth was studied in the present investigation. The results showed that needling density (ND)and needle-punching depth (PD) both had a larger effect on interlaminar shear strength (ILSS) than on compression strength and flexible strength of Needling C-C(NC-C). The mechanical properties of NC-C increased with increasing punching density in the range of 20-45 punch/cm2 and also with increasing punching depth range from10 to16mm. The NC-C with the highest ND value of 55punch/cm2 had highest ILSS value of 27 MPa.The optimized ND and PD parameters was 30 punch/cm2 and 12mm respectively, which resulted in a high value of tensile strength(119MPa), bending strength (220MPa) and compression strength (235 MPa) in the X-Y direction .


Holzforschung ◽  
2019 ◽  
Vol 73 (6) ◽  
pp. 605-611
Author(s):  
Xinwu Xu ◽  
Ling Chen ◽  
Jingquan Han ◽  
Xianxu Zhan

Abstract Proper utilization of recycled rubber is of high environmental and resource concern. In this study, a composite (COMP) was created based on high-density fiberboard sawdust (HDFS), ground tire rubber (GTR) particles and virgin high-density polyethylene (HDPE) with the ratio of HDFS:GTR:HDPE=30:21:49 and with 1% PE wax as lubricant. A dual coupling agent system, i.e. bis-(triethoxysilylpropyl) tetrasulfide (TESPT, up to 5% based on the COMP total weight) together with maleated polyethylene (MaPE, 3, 5 and 8% based on the COMP weight), was applied. The rheological properties of the hybrid during the extrusion process was evaluated in a HAAKE miniLab rheometer, and the bending and tensile properties of injected COMP were tested. The results showed that addition of MaPE and TESPT has an evident influence on the shear viscosity and stress of the COMP fluid, and the two coupling chemicals have synergetic effects. Increased content of MaPE and/or TESPT improved the tensile and bending strength of the COMP, while excessive addition of TESPT (over 1%) decreased the bending modulus. To conclude, a dual coupling system, 5% MaPE plus 1% TESPT, seems to be advantageous for the COMP behavior.


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