Study of Evolution Rule of Aggregates in Ceramic Suspension

2014 ◽  
Vol 633 ◽  
pp. 179-182
Author(s):  
Yu Ding ◽  
Kai Qi Liu ◽  
Xiao Hu Xie ◽  
Yong Feng Liu
Keyword(s):  
Interaction Potential ◽  
Process Conditions ◽  
Alumina Powder ◽  
Electrostatic Repulsion ◽  
Internal Bonding ◽  
Potential Well ◽  
Shear Forces ◽  
Ceramic Suspension ◽  
Reversible Process ◽  
Internal Bonding Strength

Using the micron alumina powder for the study, through the analysis of the ceramic suspension rheological, the generation and evolution and its mechanism of aggregates in the ceramic suspension were studied. The results showed that the number, size and intensity of aggregates will be effected by the gravitational potential or the barrier height between the particles in suspension as varying the process conditions. Generally, the formation of aggregates was corresponded to the interaction potential between particles, that is, the second potential well. Thus, their internal bonding strength is weak. In the flowing suspension, aggregates were meta-stability under shear forces, electrostatic repulsion and van der Waals potential. The variation of the aggregates was a reversible process as decomposition then reunion again.

scholarly journals Physico-Mechanical Properties of Particleboards Produced from Locally Sourced Materials

2018 ◽  
Vol 39 ◽  
pp. 112-118 ◽  
Author(s):  
Peter Pelumi Ikubanni ◽  
Adekunle Akanni Adeleke ◽  
Adeolu Adesoji Adediran ◽  
Olayinka Oluwole Agboola
Keyword(s):  
Rice Husk ◽  
Urea Formaldehyde ◽  
Modulus Of Rupture ◽  
Internal Bonding ◽  
Weight Percentage ◽  
Saw Dust ◽  
Percentage Ratio ◽  
Internal Bonding Strength ◽  
Composite Samples ◽  
Indoor And Outdoor

In this study, particleboard was produced from the blend of sawdust and rice husk with the inclusion of metallic chips and adhesives. Urea formaldehyde and gelatinous starch were used as adhesives. Particleboards (10 mm thickness) were made from varying weight percentage ratio of saw dust and rice husk using pressure in the neighbourhood of 3 N/mm2. The particleboard was tested to determine the density, modulus of rupture (MOR), modulus of elasticity (MOE) and internal bonding strength (IBS). The density of the particleboards developed varies from 762.86 to 801.60 kg/m3. The moisture content of the samples varied between 9.22% and 9.98%. The MOR, MOE and IB values varied between 5.08 MPa and 26.08 MPa; 75.38 MPa and 412.4 MPa; and 0.013 MPa to 0.07 MPa, respectively. Composite samples C, E and H values for MOR, MOE and IBS gave significant results which met with the EN, ANSI A 208.1 and USDA standards. Hence, the admixture of rice husk and sawdust together with UF adhesive will be suitable in producing particleboard that could be useful for indoor and outdoor purposes.

scholarly journals The effect of mat layers moisture content on some properties of particleboard

2019 ◽  
Vol 70 (3) ◽  
pp. 221-228
Author(s):  
Abdullah Istek ◽  
Ismail Ozlusoylu
Keyword(s):  
Mechanical Properties ◽  
Moisture Content ◽  
Modulus Of Elasticity ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Core Layer ◽  
Formaldehyde Resin ◽  
Internal Bonding ◽  
The Core ◽  
Internal Bonding Strength

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.

Development of Oriented Strand Board (OSB) Using Phenol Formaldehyde Adhesive

2014 ◽  
Vol 37 (2) ◽  
pp. 157-160
Author(s):  
Sagrika Behera ◽  
Seema Bhatt ◽  
Sneha Dobhal
Keyword(s):  
Bonding Strength ◽  
Oriented Strand Board ◽  
Phenol Formaldehyde ◽  
Solid Wood ◽  
Resin Content ◽  
Modulus Of Rupture ◽  
Internal Bonding ◽  
Poplar Wood ◽  
Screw Withdrawal ◽  
Internal Bonding Strength

Oriented strand board (OSB) was prepared using poplar wood with different resin content of phenol formaldehyde. It was observed that modulus of rupture and screw withdrawal of face and edge was more in oriented strand board as compare to solid wood. Internal bonding strength was very less in oriented strand board as compare to solid wood. It was also observed that most of the properties improve with increase in resin content.

Effects of Addition Ammonia Modified Urea-Melamine-Formaldehyde Resin on the Adhesions and Formaldehyde Emission in Plywood

2010 ◽  
Vol 113-116 ◽  
pp. 1226-1229
Author(s):  
Jun You Shi ◽  
Sheng You Ye
Keyword(s):  
Bonding Strength ◽  
Formaldehyde Emission ◽  
Formaldehyde Resin ◽  
Internal Bonding ◽  
Melamine Formaldehyde ◽  
Ammonia Content ◽  
Melamine Formaldehyde Resin ◽  
Temperature Time ◽  
Internal Bonding Strength ◽  
Modified Urea

This study was carried out to investigated the effect of addition ammonia which concentration is 20 percent modified urea-melamine-formaldehyde resin on the formald-ehyde emission and internal bonding strength, when hotpress temperature, time and pressure for every plywood was coincide.To determine and compare the effect of ammonia content 0, 2.5, 5 percent by weight of formaldehyde were used. To determine the level of formaldehyde emission, we used the desiccator method. The formaldehyde emissions from poplar multi-plywoods were significantly decreased with increased additions of ammonia, at a ammonia ratio of only 2.5%, the formaldehyde emission level of the un-coated samples which is seven-ply plywood can meet the F☆☆☆ grade, and also the samples with 2.5% ammonia modified resin hot-pressed showed good bonding strength.

scholarly journals Mechanical Properties of Particleboard using Acacia Mangium Wood Particles Binded With Seaweed-Based Adhesives

2021 ◽  
Vol 2129 (1) ◽  
pp. 012001
Author(s):  
K C Liew ◽  
A R Samin
Keyword(s):  
Mechanical Properties ◽  
Bonding Strength ◽  
Urea Formaldehyde ◽  
Brown Seaweed ◽  
Acacia Mangium ◽  
Modulus Of Rupture ◽  
Bending Test ◽  
Internal Bonding ◽  
Wood Particles ◽  
Internal Bonding Strength

Abstract The purpose of this study was to evaluate the mechanical properties of particleboards made from Acacia mangium wood particles binded with three different types of seaweed-based adhesive. Red seaweed (RS), brown seaweed (BS) and green seaweed (GS) were used as the seaweed-based adhesives., while particleboard using urea formaldehyde (UF) adhesive was produced as control. Adhesives and wood particles were mixed and then undergone mat-forming, pre-pressing, hot-pressing and conditioning process. The test pieces for bending test (Modulus of Elasticity, MOE; Modulus of Rupture, MOR), and internal bonding strength (IB) were cut into size according to JIS A 5908: 2003. From mechanical properties results attained, for internal bonding strength test, all boards using RS, BS and GS adhesives were found to be significantly different at p≤0.05. Apart from that, RS adhesive showed highest MOE and MOR at 529.4259 N/mm2 and 1.7900 N/mm2, respectively. As a conclusion, the mechanical properties of particleboard using RS, BS, and GS adhesives showed RS stands out as the better adhesive among them which have significant effects on its strength.

scholarly journals PENGARUH TEMPERATUR PEREBUSAN JERAMI TERHADAP SIFAT FISIS MEKANIS PAPAN PARTIKEL

2017 ◽  
Vol 4 (2) ◽  
pp. 157
Author(s):  
M. I. Iskandar
Keyword(s):  
Physical Properties ◽  
Flexural Modulus ◽  
Effect Of Temperature ◽  
Internal Bonding ◽  
Particle Board ◽  
Thickness Swelling ◽  
Mechanical And Physical Properties ◽  
Extractive Substances ◽  
Effect Of Treatment ◽  
Internal Bonding Strength

Effect of Temperature of Straw Boiling on Mechanical and Physical Properties of Particle Board          Levels of extractive substances in the straw as much as 10-15% and 12-18% silica content respectively. Two of these substances can inhibit good adhesion bonding between the particles during the sealing process. Treatment of straw boiling  before gluing process can reduce the negative effects of extractive substances to the bonding adhesive. The purpose of this study was to determine the effect of temperature of the boiling straw on mechanical and physical properties of particle board. The tested physical properties included density, moisture content, thickness swelling and water absorption while the mechanical properties tested included flexural modulus, fracture modulus, internal bonding strength and screw holding strength. Analysisof statistic of the data used was Complete Random Design (RAL). The treatment consisted of a five-level with three replications so that the total number of trials was fifteen. To determine the effect of treatment carried out the Analysis of Variance. To determine the effect of treatment was significantly different would do a further test the Duncan's multiple range test. Processing data using SAS software, version 6123. The results showed an increase in the temperature of straw boiling was very significant and fluctuative on the properties of particle board and the moisture content, thickness swelling 24 hours, flexural modulus (MOE), fracture modulus (MOR), but did not significant affect the density and internal bonding strength. Boiling temperature 40⁰C on straw produce panels with the best qualities. The properties of particle board research results that met the requirements of Standard JIS A 5908: 215 only the density and moisture content.Keywords: temperature, boiling, straw, mechanical physical properties ABSTRAK         Kadar zat ekstraktif dalam jerami sebanyak 10-15% dan kadar silika 12-18%. Dua zat tersebut dapat menghambat ikatan rekat yang baik antar partikel pada waktu proses perekatan. Perlakuan perebusan jerami sebelum proses perekatan dapat mengurangi pengaruh negatif zat ekstraktif terhadap ikatan rekat. Tujuan penelitian ini adalah untuk mengetahui pengaruh temperatur perebusan jerami terhadap sifat fisis mekanis papan partikel. Sifat fisis yang diuji meliputi kerapatan, kadar air, pengembangan tebal dan daya serap air sedangkan sifat mekanis yang diuji meliputi modulus lentur, modulus patah, keteguhan rekat internal dan kuat pegang sekrup. Analisis statistik data yang digunakan adalah Rancangan Acak Lengkap (RAL). Perlakuan terdiri dari lima taraf dengan ulangan sebanyak tiga sehingga jumlah total percobaan adalah lima belas. Untuk mengetahui pengaruh dari perlakuan dilakukan analisis ragam (Analysis of Variance). Untuk mengetahui pengaruh berbeda nyata perlakuan dilakukan uji lanjut dengan uji wilayah berganda Duncan. Pengolahan data menggunakan software SAS versi 6.123. Hasil penelitian menunjukkan peningkatan temperatur perebusan jerami berpengaruh sangat nyata dan fluktuatif terhadap sifat-sifat papan partikel dan kadar air, pengembangan tebal 24 jam, modulus lentur (MOE), modulus patah (MOR), tetapi tidak berpengaruh nyata terhadap kerapatan dan keteguhan rekat internal. Perebusan jerami pada suhu 40⁰C menghasilkan panil dengan sifat-sifat terbaik. Sifat-sifat papan partikel hasil penelitian yang memenuhi persyaratan Standar JIS A 5908:215 hanya kerapatan dan kadar air.Kata kunci: temperatur, perebusan, jerami, sifat fisis dan mekanis

scholarly journals On the Temperature Role in the Tunneling Process at the Low-Energy Nuclear Fusion

2020 ◽  
Vol 65 (11) ◽  
pp. 958
Author(s):  
B.E. Grinyuk ◽  
I.V. Simenog
Keyword(s):  
Temperature Dependence ◽  
Interaction Potential ◽  
Coulomb Barrier ◽  
Low Temperatures ◽  
Low Energy ◽  
Potential Well ◽  
Oscillator Potential ◽  
Temperature Dependences ◽  
Probable Role

The temperature dependence of the coefficient of tunneling through the Coulomb barrier is estimated for nuclei of the hydrogen isotopes at comparatively low temperatures using a model of screened Coulomb interaction potential between the isotopes put inside an external oscillator potential well. The temperature dependences for the tunneling coefficient are calculated for pp-, pd-, pt-, dd-, and dt-processes at different screening radii. The probable role of pp-reactions is discussed.

Mechanical and Physical Properties of Cement-Bonded Perticleboard Made from Tea Residues and Hardboards

2011 ◽  
Vol 471-472 ◽  
pp. 572-577 ◽  
Author(s):  
Hüsnü Yel ◽  
Ayfer Dönmez Çavdar ◽  
Hülya Kalaycioğlu
Keyword(s):  
Weight Basis ◽  
Modulus Of Rupture ◽  
Lignocellulosic Material ◽  
Internal Bonding ◽  
Thickness Swelling ◽  
Mean Values ◽  
Cement Ratio ◽  
Mechanical And Physical Properties ◽  
The Mean ◽  
Internal Bonding Strength

The residues of tea factory and waste hardboards are generally incinerated without utilizing their heat performances. The first objective of this study was to manufacture cement bonded particleboard using residues of tea factory (Camellia sinenses L.) and waste hardboards. The second objective was to evaluate modulus of rupture (MOR), modulus of elasticity (MOE), internal bonding strength (IB), water absorption (WA) and thickness swelling (TS) properties of the boards produced. The boards were produced at two density levels of 800 and 1200 kg/m3 and at five lignocellulosic mixture ratios of poplar chips/hardboards/tea residues (1/0/0; 1/1/0; 1/0/1; 0/1/0; 0/0/1, based on weigth). All the boards were produced at lignocellulosic material/cement ratio of 1:2.75 on a weight to weight basis. As cement curing accelerators, Al2(SO4)3 and Na2SiO3 were used at ratios of 1.5% and 3.5%, based on cement weight, respectively. The MOR values ranged from 0.8 to 10.99 MPa and MOE values ranged from 254 to 2979 MPa. The mean values of WA and TS after 24 h of water soaking of the cemen bonded particleboards ranged from 28% to 43.5% and 1.3% to 8.08%, respectively.

Biofilm structures

1995 ◽  
Vol 32 (8) ◽  
pp. 35-43 ◽  
Author(s):  
M. C. M. van Loosdrecht ◽  
D. Eikelboom ◽  
A. Gjaltema ◽  
A. Mulder ◽  
L. Tijhuis ◽  
...  
Keyword(s):  
Growth Rate ◽  
Shear Rate ◽  
Loading Rate ◽  
Process Conditions ◽  
Shear Forces ◽  
Surface Loading ◽  
Shear Rates ◽  
Microbial Characteristics ◽  
Biofilm Structure ◽  
Low Shear

The influences of reactor conditions (substrate loading rate and shear) and microbial characteristics (yield and growth rate) on the structure of biofilms is discussed. Based on research on the formation of biofilms in Biofilm Airlift Suspension (BAS) reactors a hypothesis is postulated that the ratio between biofilm surface loading and shear rate determines the biofilm structure. When shear forces are relatively high only a patchy biofilm will develop, whereas at low shear rates the biofilm becomes highly heterogeneous with many pores and protuberances. In case of a right balance smooth and stable biofilms can be obtained. A hypothesis for the evolution of biofilm structures as a function of process conditions is formulated.

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