scholarly journals Preparation and Study Hardness and Thermal Conductivity (Tc) to Polyester Resin Composite with (Titanium Dioxide, Zinc Oxide, Acrylonitril, Wood Flour Coconut

2010 ◽  
Vol 7 (4) ◽  
pp. 1400-1409
Author(s):  
Baghdad Science Journal
Keyword(s):  
Thermal Conductivity ◽  
Polyester Resin ◽  
Wood Flour ◽  
Resin Composite ◽  
Experimental Results ◽  
Thermal Isolation ◽  
Molding Method ◽  
Maximum Value ◽  
Hardness Tests ◽  
Virgin Sample

This study is attempt to improve thermal isolation through measuring thermal conductivity composite of on polyester resin with fillers of (TiO2, ZnO, Acrylonitril, wood flour Coconut (Wf). The grain size of the fillers is 200 µm. The number of samples is (16) in addition to the virgin sample; these samples are prepared by cast molding method for polyester with filler volume fractions (5%, 10%, 15% and 20%). Shore hardness tests were used to measure the hardness and Lee disk method for thermal conductivity. The experimental results showed that the (20% ZnO) sample has the maximum value of thermal conductivity where (20% w.f) has minimum thermal conductivity .on the other hand (15% ZnO) sample give the maximum value of hardness where (20% w.f) sample gave the minimum value of hardness. From this study there is an important factor that should be observed that is the relationship between hardness and thermal conductivity. The study prove that the experimental results satisfy the theoretical assumptions in that the additive material (fillers) of metals base increase thermal conductivity where the material of cellulose base decrease the thermal conductivity and give good thermal isolation but with low hardness and all the result above the refry sample .

scholarly journals Effect of calcium carbonate filler and alkali treatment on physical and elastic properties of jute mat reinforced polyester resin composites

2020 ◽  
Vol 26 (2) ◽  
pp. 61-68
Author(s):  
Rahima Nasrin ◽  
Salma Begum ◽  
MA Gafur ◽  
AH Bhuiyan ◽  
AH Bhuiyan
Keyword(s):  
Calcium Carbonate ◽  
Elastic Properties ◽  
Polyester Resin ◽  
Alkali Treatment ◽  
Reinforced Composites ◽  
Soaking Time ◽  
Molding Method ◽  
Maximum Value ◽  
Carbonate Filler ◽  
Press Molding

Polyester resin-jute mat reinforced composites with different wt% of calcium carbonate (CaCO3) filler were fabricated using a simple cold press molding method. The effects of CaCO3 filler and alkali (NaOH) treatment on various physical and elastic properties were evaluated. Water absorption (WA) increases with the increase of soaking time and load. The maximum WA was observed for 5 wt% addition of CaCO3 and for more CaCO3, WA decreases. The ultimate tensile strength (UTS) and flexural strength (FS) decreases with the addition of CaCO3 for 0.5 wt% NaOH treated composites but for 5 wt% NaOH treated composites UTS and FS increases with the addition of CaCO3 filler. The optimum filler addition is about 5 wt% CaCO3. With the addition of CaCO3, tangent modulus increases for 0.5 wt% NaOH treated composites and for 5 wt% NaOH treated composites it increases up to a maximum value and then decreases. The effect of load on tensile and flexural properties is also discussed. Bangladesh Journal of Physics, 26(2), 61-68, December 2019

The Preparation and Properties of Si3N4-Filled Epoxy Resin Composites for Electronic Packaging

2007 ◽  
Vol 336-338 ◽  
pp. 1346-1349 ◽  
Author(s):  
Ren Li Fu ◽  
Ke Xin Chen ◽  
Jin Tang ◽  
Yuan Shen ◽  
Hong He
Keyword(s):  
Thermal Conductivity ◽  
Dielectric Constant ◽  
Epoxy Resin ◽  
Volume Fraction ◽  
Resin Composite ◽  
Thermal Conductance ◽  
Molding Method ◽  
Epoxy Resin Composite ◽  
Filled Composite ◽  
Press Molding

Si3N4-filled epoxy resin composite was fabricated employing liquid press molding method. Properties, such as thermal conductivity, dielectric constant of Si3N4-filled epoxy resin composite were evaluated, the effect of the content of Si3N4 and surface treatment of the filler was also considered. A silane coupling agent, namely NH2−(CH2)3Si−(OC2H5)3, was applied to functionalize the surface of Si3N4 filler. Experimental results showed that the thermal conductivity of the composites is strongly dependent on the filler and is dominated by the interface of epoxy resin and Si3N4 particles. As the Si3N4 volume fraction increasing, thermal conductance of Si3N4-filled composite was improved obviously, especially for that of silane-treated Si3N4 powder filled composite. Dielectric constant of the composite increases linearly, however, it still remains at a relatively low level (<5, at 1MHz).

scholarly journals Physical, Mechanical and Thermal Properties of Sand Reinforced Polyester Resin Composite

2015 ◽  
Vol 56 ◽  
pp. 99-103 ◽  
Author(s):  
Md Mahfujul Islam ◽  
Md Alamgir Kabir ◽  
Humayun Kabir ◽  
Farid Ahmed ◽  
Md Abdul Gafur
Keyword(s):  
Compressive Strength ◽  
Thermal Properties ◽  
Polyester Resin ◽  
Resin Composite ◽  
Unsaturated Polyester ◽  
Hardness Test ◽  
Mechanical And Thermal Properties ◽  
Flexure Strength ◽  
Molding Method ◽  
Polyester Composite

Sand reinforced polyester composite have been prepared by compression molding method with a variety of range (0,15,30,45 60%) sand respect to the unsaturated polyester resin. various parameter like mechanical, Physical and thermal properties of sand reinforced, polyester resin composite have been determined by various technique like water compressive strength ,flexural strength , hardness and thermal analysis. Physical properties like density and water intake increases with the addition of sand ,compressive strength increases but flexure strength decreases with the amount of sand, on hardness test, Vickers hardness increases but on leeb rebound it decreases with amount of sand, and finally thermal conductivity decreases with the addition of sand.

scholarly journals A Novel Gate Drive Circuit for Suppressing Turn-on Oscillation of Non-Kelvin Packaged SiC MOSFET

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2449
Author(s):  
Hongyan Zhao ◽  
Jiangui Chen ◽  
Yan Li ◽  
Fei Lin
Keyword(s):  
Thermal Conductivity ◽  
Breakdown Voltage ◽  
Basic Principle ◽  
Double Pulse ◽  
Experimental Results ◽  
Switching Frequency ◽  
Turn On ◽  
Proof Testing ◽  
Gate Driver ◽  
Drive Circuit

Compared with a silicon MOSFET device, the SiC MOSFET has many benefits, such as higher breakdown voltage, faster action speed and better thermal conductivity. These advantages enable the SiC MOSFET to operate at higher switching frequencies, while, as the switching frequency increases, the turn-on loss accounts for most of the loss. This characteristic severely limits the applications of the SiC MOSFET at higher switching frequencies. Accordingly, an SRD-type drive circuit for a SiC MOSFET is proposed in this paper. The proposed SRD-type drive circuit can suppress the turn-on oscillation of a non-Kelvin packaged SiC MOSFET to ensure that the SiC MOSFET can work at a faster turn-on speed with a lower turn-on loss. In this paper, the basic principle of the proposed SRD-type drive circuit is analyzed, and a double pulse platform is established. For the purpose of proof-testing the performance of the presented SRD-type drive circuit, comparisons and experimental verifications between the traditional gate driver and the proposed SRD-type drive circuit were conducted. Our experimental results finally demonstrate the feasibility and effectiveness of the proposed SRD-type drive circuit.

scholarly journals 3D Thermal Network Supported by CF Felt for Improving the Thermal Performance of CF/C/Epoxy Composites

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 980
Author(s):  
Xinfeng Wu ◽  
Yuan Gao ◽  
Tao Jiang ◽  
Lingyu Zheng ◽  
Ying Wang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electronic Devices ◽  
Epoxy Composites ◽  
Operating Efficiency ◽  
Impregnation Method ◽  
Molding Method ◽  
Needle Punching ◽  
3D Network ◽  
Network Method ◽  
Process Method

The heat generated by a high-power device will seriously affect the operating efficiency and service life of electronic devices, which greatly limits the development of the microelectronic industry. Carbon fiber (CF) materials with excellent thermal conductivity have been favored by scientific researchers. In this paper, CF/carbon felt (CF/C felt) was fabricated by CF and phenolic resin using the “airflow network method”, “needle-punching method” and “graphitization process method”. Then, the CF/C/Epoxy composites (CF/C/EP) were prepared by the CF/C felt and epoxy resin using the “liquid phase impregnation method” and “compression molding method”. The results show that the CF/C felt has a 3D network structure, which is very conducive to improving the thermal conductivity of the CF/C/EP composite. The thermal conductivity of the CF/C/EP composite reaches 3.39 W/mK with 31.2 wt% CF/C, which is about 17 times of that of pure epoxy.

scholarly journals Synthesis, Characterization and Testing of Antimicrobial Activity of Composites of Unsaturated Polyester Resins with Wood Flour and Silver Nanoparticles

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1122
Author(s):  
Przemysław Pączkowski ◽  
Andrzej Puszka ◽  
Malgorzata Miazga-Karska ◽  
Grażyna Ginalska ◽  
Barbara Gawdzik
Keyword(s):  
Silver Nanoparticles ◽  
Staphylococcus Epidermidis ◽  
Polyester Resin ◽  
Wood Flour ◽  
Unsaturated Polyester ◽  
Thermomechanical Properties ◽  
Resin Composites ◽  
Polyester Resins ◽  
Before And After

This paper presents the properties of the wood-resin composites. For improving their antibacterial character, silver nanoparticles were incorporated into their structures. The properties of the obtained materials were analyzed in vitro for their anti-biofilm potency in contact with aerobic Gram-positive Staphylococcus aureus and Staphylococcus epidermidis; and aerobic Gram-negative Escherichia coli and Pseudomonas aeruginosa. These pathogens are responsible for various infections, including those associated with healthcare. The effect of silver nanoparticles incorporation on mechanical and thermomechanical properties as well as gloss were investigated for the samples of composites before and after accelerating aging tests. The results show that bacteria can colonize in various wrinkles and cracks on the composites with wood flour but also the surface of the cross-linked unsaturated polyester resin. The addition of nanosilver causes the death of bacteria. It also positively influences mechanical and thermomechanical properties as well as gloss of the resin.

Principle and structure of a multi-chamber piezoelectric pump with large flow rate integrated into printed circuit board

2022 ◽  
pp. 1045389X2110721
Author(s):  
Yun-Hao Peng ◽  
Dai-Hua Wang ◽  
Lian-Kai Tang
Keyword(s):  
Flow Rate ◽  
Compression Ratio ◽  
Layer Structure ◽  
Experimental Results ◽  
Processing Technology ◽  
Rate Model ◽  
Piezoelectric Pump ◽  
Central Deflection ◽  
Maximum Value ◽  
Large Flow

Parametric simulation of multi-chamber piezoelectric pump proposed by authors shows that its flow rate is positively correlated with chamber compression ratio when height of chamber wall is not less than central deflection of circular piezoelectric unimorph actuator (CPUA). Therefore, in this paper, principle and structure of multi-chamber piezoelectric pump with novel CPUAs with three-layer structure are proposed and realized, so as to improve its chamber compression ratio, and then improve its flow rate. Its processing technology compatible with PCB processing technology is studied and its flow rate model is established. Central deflection of CPUA with three-layer structure and the flow rate characteristics are tested. Experimental results show that when the central deflection of CPUA with three-layer structure reaches the maximum value of 106.8 μm, the chamber compression ratio and flow rate of multi-chamber piezoelectric pump reach the maximum value of 50% and 3.11 mL/min, respectively. The maximum flow rate is increased by 622% compared to unimproved pump. By comparing experimental results with numerical and finite element simulation results, the realized multi-chamber piezoelectric pump has large flow rate and the established flow rate model can predict its flow rate.

scholarly journals Undergraduate Study of Thermal Conductivity of Metals

2002 ◽  
Vol 24 (3) ◽  
pp. 296-305
Author(s):  
T. B. Ferrari ◽  
S. H. Hara ◽  
J. L. Aziani ◽  
L. Rocha ◽  
E. de Paula ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Experimental Results ◽  
Empirical Results ◽  
Undergraduate Study ◽  
Link Theory ◽  
Semi Empirical ◽  
Empirical Corrections

In this work we analyze an undergraduate experiment used to determine the thermal conductivity of metals (K). We introduce few modifications in order to offer the student the chance to explore dierent models, learning the basic scientiffic method of developing appropriate and improved explanations for each experiment in order to better link theory and empirical results. Semi-empirical corrections are introduced in the system in order to check the experimental results according to previously reported K values. As specific cases we use copper [K = 0.92 cal /(°C s cm)], aluminum [K = 0.49 cal /(°C s cm)] and brass [K = 0.26 cal /(°C s cm)] cylinders.

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