scholarly journals Effect of Hot-Pressing Temperature on Characteristics of Straw-Based Binderless Fiberboards with Pulping Effluent

Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 922 ◽  
Author(s):  
Jiajun Wang ◽  
Bo Wang ◽  
Junliang Liu ◽  
Lin Ni ◽  
Jianzhang Li
Keyword(s):  
Hot Pressing ◽  
Mechanical Performance ◽  
Thermal Transitions ◽  
Surface Color ◽  
Pressing Temperature ◽  
Surface Appearance ◽  
Property Data ◽  
Ft Ir ◽  
The Difference

This study aimed to improve straw-based fiberboard properties without resins by adding pulping effluent as well as to investigate the difference among boards under variable hot-pressing temperatures. The characterization of fiberboards produced from wheat straw under pressing temperatures ranging from 160 to 200 °C was first described. The surface appearance, surface chemistry, thermal transitions, and mechanical performance of the boards were evaluated to investigate the effect of varying hot-pressing temperature. The results indicated that the surface color of boards became darker when the temperature was above 190 °C. Additionally, Fourier transform infrared (FT-IR) measurements showed that more low-molecular constituents and hydrogen bonds were produced under higher pressing temperatures. Furthermore, the physical and mechanical property data were analyzed statistically using one-way analysis of variance (ANOVA) and Tukey’s tests (α = 0.05). The results demonstrated that straw-based fiberboards with effluent under 190 °C exhibited superior strength and water resistance capacities, and showed great potential in commercial decorating and packaging applications.

Study on Structural Plywood Production Technology from Eucalyptus/poplar

2012 ◽  
Vol 476-478 ◽  
pp. 1547-1552 ◽  
Author(s):  
Li Hong Yao ◽  
Xi Ming Wang ◽  
Ben Hua Fei
Keyword(s):  
Bond Strength ◽  
Production Technology ◽  
Hot Pressing ◽  
Rapid Development ◽  
Practical Significance ◽  
Pressing Pressure ◽  
Poplar Plantation ◽  
Pressing Temperature ◽  
Pressing Time ◽  
The Difference

With the rapid development of wooden structure buildings in China, the demand for structural plywood enlarges significantly. Eucalyptus and poplar plantation is a very wide area of growth in china, therefore, there is practical significance to use eucalyptus and poplar plantation to produce wooden structural plywood. This study uses orthogonal test on pressing temperature, pressing time, pressing pressure, veneer glue spread - four factors influence the bond strength of structural plywood from Eucalyptus/poplar, and has obtained the superior technology. The results show that hot pressing temperature, pressing time, pressing pressure, veneer glue spread –four factors affect the bond strength of the structure plywood significantly, but the difference among the three veneer glue spread levels is not significantly. The better production technology is hot pressing temperature 135 °C, pressing time 24 min, pressing pressure 1.2 Mpa, veneer glue spread 320 g/m2.

Synthesis and Characterization of Novel Poly (aryl ether sulfone ketone) S Containing M-Sulfonylbenzonyl Linkage in the Main Chains

2011 ◽  
Vol 396-398 ◽  
pp. 1518-1522
Author(s):  
Feng Ding ◽  
Da Zhi Wang ◽  
Shao Yin Zhang ◽  
Tian Xing Liu
Keyword(s):  
1H Nmr ◽  
Differential Scanning Calorimeter ◽  
Benzoyl Chloride ◽  
Mechanical Performance ◽  
Synthesis And Characterization ◽  
Aryl Ether ◽  
Ft Ir

A low expense chloro-monomer, 1-(4'-chloro-1-benzoyl)-3-(4'-1-choro-benzene sulfonyl)-benzene(CBCBSB), was synthesized by the Friedel-Crafts reaction of m-chlorosu1fonyl benzoyl chloride with chlorobenzene. A novel poly (aryl ether sulfone ketone)s (PAESK) containing m-sulfonylbenzoyl linkages in the main chains were prepared by copolycondensation of CBCBSB with hydroquinone in N, N-Dimethylacetamide (DMAc). The structure of PAESK was confirmed by FT-IR, 1H-NMR and characterized by XRD. thermogravimetry (TG) and Differential Scanning Calorimeter (DSC) were carried out to demonstrate its good melt processability. The polymer exhibited the better solubility in chloroform, N-methyl-2-pyrrlidone(NMP), dimethylacetamide(DMAC), dimethylformamide (DMF) and dimethylsulfoxide (DMSO) and excellent mechanical performance.

Synthesis and Characterization of Polyaniline Copolymer

2012 ◽  
Vol 217-219 ◽  
pp. 551-554
Author(s):  
Ting Xi Li ◽  
Yu Hua Zhao ◽  
Qian Li ◽  
Cheng Qian Yuan ◽  
Quan Liang Chen ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Infrared Spectroscopy ◽  
Thermogravimetric Analysis ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir ◽  
The Difference ◽  
Thermal Stability Of

Abstract. Polyaniline (PANI) and p-phenylenediamine (p-PDA)-aniline copolymer were prepared via a same microemulsion method. The structures of the PANI and p-PDA-aniline copolymer were characterized by infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis（TGA）. The results revealed the difference of synthesis and characterization between PANI and p-PDA-aniline copolymer. It was shown that structure of the copolymer is almost similar to that of PANI, but the p-PDA-aniline copolymer has a better crystallization than PANI, and the thermal stability of the copolymer is higher than that of pure PANI.

Effect of Blending Modification on Tensile Performance of CPE/PVC

2011 ◽  
Vol 284-286 ◽  
pp. 1732-1735
Author(s):  
Xiao Ling Xie ◽  
Wen Hai Li ◽  
Ying Hui Wei
Keyword(s):  
Tensile Strength ◽  
Polyvinyl Chloride ◽  
Hot Pressing ◽  
Mechanical Performance ◽  
Dioctyl Phthalate ◽  
Test Results ◽  
Pressing Temperature ◽  
Chlorinated Polyethylene ◽  
Breaking Elongation ◽  
Tensile Performance

The samples were modified by using chlorinated polyethylene (CPE) to increase the toughness and using dioctyl phthalate (DOP) to increase the plasticity. The tensile strength and breaking elongation of the samples were studied by changing the chlorinated polyethylene (CPE) and dioctyl phthalate (DOP) contents and the hot-pressing temperature. It was shown by the test results that, with the increase of chlorinated polyethylene (CPE) and dioctyl phthalate (DOP) contents, the tensile strength of the samples was decreased while the breaking elongation was increased. By increasing the hot-pressing temperature, the blending effect between polyvinyl chloride (PVC) and chlorinated polyethylene (CPE) as well as the mechanical performance of the samples were increased, however, over-high hot-pressing temperature would result in plasticizer precipitation.

scholarly journals Lignin Inter-Diffusion Underlying Improved Mechanical Performance of Hot-Pressed Paper Webs

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2485
Author(s):  
Amanda Mattsson ◽  
Tove Joelsson ◽  
Arttu Miettinen ◽  
Jukka A. Ketoja ◽  
Gunilla Pettersson ◽  
...  
Keyword(s):  
Hot Pressing ◽  
Structural Changes ◽  
Mechanical Performance ◽  
Thermomechanical Pulp ◽  
Similar Data ◽  
Pressing Temperature ◽  
Wet Strength ◽  
Wide Range ◽  
Solids Content ◽  
Paper Webs

Broader use of bio-based fibres in packaging becomes possible when the mechanical properties of fibre materials exceed those of conventional paperboard. Hot-pressing provides an efficient method to improve both the wet and dry strength of lignin-containing paper webs. Here we study varied pressing conditions for webs formed with thermomechanical pulp (TMP). The results are compared against similar data for a wide range of other fibre types. In addition to standard strength and structural measurements, we characterise the induced structural changes with X-ray microtomography and scanning electron microscopy. The wet strength generally increases monotonously up to a very high pressing temperature of 270 °C. The stronger bonding of wet fibres can be explained by the inter-diffusion of lignin macromolecules with an activation energy around 26 kJ mol−1 after lignin softening. The associated exponential acceleration of diffusion with temperature dominates over other factors such as process dynamics or final material density in setting wet strength. The optimum pressing temperature for dry strength is generally lower, around 200 °C, beyond which hemicellulose degradation begins. By varying the solids content prior to hot-pressing for the TMP sheets, the highest wet strength is achieved for the completely dry web, while no strong correlation was observed for the dry strength.

scholarly journals Preparation and Characterization of Bio-oil Phenolic Foam Reinforced with Montmorillonite

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1471 ◽  
Author(s):  
Pingping Xu ◽  
Yuxiang Yu ◽  
Miaomiao Chang ◽  
Jianmin Chang
Keyword(s):  
Flame Retardant ◽  
Mechanical Performance ◽  
Flame Resistance ◽  
Promising Alternative ◽  
Phenolic Foam ◽  
Bio Oil ◽  
Ft Ir ◽  
The Fourier Transform ◽  
Small Content

Introducing bio-oil into phenolic foam (PF) can effectively improve the toughness of PF, but its flame retardant performance will be adversely affected and show a decrease. To offset the decrease in flame retardant performance, montmorillonite (MMT) can be added as a promising alternative to enhance the flame resistance of foams. The present work reported the effects of MMT on the chemical structure, morphological property, mechanical performance, flame resistance, and thermal stability of bio-oil phenolic foam (BPF). The Fourier transform infrared spectroscopy (FT-IR) result showed that the –OH group peaks shifted to a lower frequency after adding MMT, indicating strong hydrogen bonding between MMT and bio-oil phenolic resin (BPR) molecular chains. Additionally, when a small content of MMT (2–4 wt %) was added in the foamed composites, the microcellular structures of bio-oil phenolic foam modified by MMT (MBPFs) were more uniform and compact than that of BPF. As a result, the best performance of MBPF was obtained with the addition of 4 wt % MMT, where compressive strength and limited oxygen index (LOI) increased by 31.0% and 33.2%, respectively, and the pulverization ratio decreased by 40.6% in comparison to BPF. These tests proved that MMT can blend well with bio-oil to effectively improve the flame resistance of PF while enhancing toughness.

A Study on Sliced Bamboo Veneer-Chinese Fir Glulam Composite Panel

2010 ◽  
Vol 168-170 ◽  
pp. 2033-2036
Author(s):  
Chun Gui Du
Keyword(s):  
Hot Pressing ◽  
Chinese Fir ◽  
Woven Fabric ◽  
Composite Panel ◽  
Bottom Surface ◽  
Technological Parameters ◽  
Surface Color ◽  
Pressing Temperature ◽  
Pressing Time ◽  
Unit Pressure

Previous studies have indicated that Chinese fir glulam has many defects on surface: color is singleness, knot is more, surface is roughness, etc. This paper presents a study on the manufacturing technology of sliced bamboo veneer-Chinese fir glulam composite panel. Sliced bamboo veneer were glued on both the top and bottom surface of Chinese fir glulam. The results showed: (1)sliced bamboo veneer can beautify the surface of Chinese fir glulam; (2)sliced bamboo veneer should directly overlay on the surface of Chinese fir glulam, and it is not suitable back lining non-woven fabric in gluing; (3)the optimal composite technological parameters are: unit pressure: 0.7MPa; hot pressing temperature: 100°C; hot pressing time: 4min.

The Fiberboard of Hot Pressing Process Optimization and Combination Performance Characterization

2010 ◽  
Vol 44-47 ◽  
pp. 2278-2282
Author(s):  
Ming Hui Guo ◽  
Jian Peng Hu
Keyword(s):  
Hot Pressing ◽  
Mechanical Performance ◽  
Wood Fiber ◽  
Pressing Pressure ◽  
Interface Properties ◽  
Test Results ◽  
Pressing Temperature ◽  
Pressing Time ◽  
Instrument Analysis ◽  
Natural Wood

To pack a certain quality ratio ammonium lignosulfonate / urea as a filler into the natural wood fiber, Using flat pressure process fiberboard materials, Optimize the hot pressing technique that the filler is 20% (The quality ratio of lignosulfonate/ urea is 5: 3), slab moisture content is 13%, hot-pressing temperature is 190°C; hot-pressing time is 7 minutes, hot-pressing pressure is 2MPa and 1% paraffin emulsion. Verifying test results show that mechanical performance is stable and reliable process. Analyze the reactivity of fiberboard packing, fiber gathered, the microstructure of interface properties with the application of FTIR, XRD and ESEM and other modern instrument analysis technology.

Analisis Karakterisasi Teknologi Direct Sequence Spread Spectrum Dan Frequency Hopping Spread Spectrum

2019 ◽  
Vol 2 (2) ◽  
pp. 129-138
Author(s):  
Fawzan Galib Abdul Karim Bawahab ◽  
Elvan Yuniarti ◽  
Edi Kurniawan
Keyword(s):  
Spread Spectrum ◽  
Communication Systems ◽  
Multiple Access ◽  
Frequency Hopping ◽  
Direct Sequence Spread Spectrum ◽  
Direct Sequence ◽  
Frequency Hopping Spread Spectrum ◽  
Two Systems ◽  
The Difference

Abstrak. Pada penelitian ini, telah dilakukan analisa karakterisasi pada teknologi Direct Sequence Spread Spectrum dan Frequency Hopping Spread Spectrum, sebagai salah satu teknik multiple-access pada sistem komunikasi. Karakterisasi dilakukan untuk mencari bagaimana cara meningkatkan keoptimalan kedua sistem tersebut, dalam mengatasi masalah interferensi dengan sistem dan channel yang sama. Dan juga untuk menentukan veriabel apa yang mempengaruhi keoptimalan kedua sistem tersebut. Karakterisasi dilakukan dengan menentukan variabel-variabel yang mempengaruhi keoptimalan keduanya. Hasil dari karakterisasi, diketahui variabel-variabel yang mempengaruhi kemampuan sistem DSSS yaitu nilai frekuensi spreading (). Sedangkan untuk sistem FHSS yaitu nilai frekuensi spreading ( dan ) dan selisih antara frekuensi hopping data dengan frekuensi hopping interferensi . Kata Kunci: BER, DSSS, FHSS, Interference, Spread spectrum. Abstract. In this study, characterization of Direct Sequence Spread Spectrum and Frequency Hopping Spread Spectrum technologies have been done, as one of the multiple-access techniques in communication systems. Characterization is done to find out how to improve the ability of the two systems, in solving interference problems with the same system and channel. And also to determine what veriabel affects the ability of the two systems. Characterization is done by determining the variables that affect the ability of both. The results of the characterization, known variables that affect the ability of the DSSS system are the spreading frequency value (). As for the FHSS system, the spreading frequency value ( and ) and the difference between frequency hopping data with frequency hopping interference .

Spectral Investigation on the Growth and Characterization of NLO Crystals of Thiourea Succinic Acid Single Crystal.

2015 ◽  
Vol 2 (2) ◽  
pp. 70-73
Author(s):  
Kannan.P ◽  
Thambidurai.S ◽  
Suresh.N
Keyword(s):  
Single Crystal ◽  
Succinic Acid ◽  
Slow Evaporation Technique ◽  
Absorption Studies ◽  
Dta Analysis ◽  
Evaporation Technique ◽  
Ft Ir ◽  
Ir Spectroscopic ◽  
Thermal Stability Of

Growth of optically transparent single crystals of thiourea succinic acid (TUSA) was grown successfully from aqueous solution by slow evaporation technique. The crystal structure was elucidated using the single crystal XRD. The various functional groups and the modes of vibrations were identified by FT-IR spectroscopic analysis. The optical absorption studies indicate that the optical transparency window is quite wide making its suitable for NLO applications. Thermal stability of the crown crystal carried out by TGA-DTA analysis.

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