Investigation on Electromechanical Properties of Solid Silicone Rubber Composites with Conductive Carbon Filler

2019 ◽  
Vol 969 ◽  
pp. 409-414
Author(s):  
B.S. Manohar Shankar ◽  
S.M. Kulkarni
Keyword(s):  
Silicone Rubber ◽  
Mixing Time ◽  
Curing Temperature ◽  
Compression Moulding ◽  
Carbon Filler ◽  
Moulding Process ◽  
Active Filler ◽  
Energy Harvesters ◽  
Electromechanical Transduction ◽  
Roll Mill

Dielectric elastomers belonging to the class of electroactive polymers are promising materials for electromechanical transduction. They are used as actuators, capacitive sensors and energy harvesters. In the present study solid silicone rubber-super conducting carbon black composites are prepared through compression moulding process and evaluated for their mechanical and dielectric properties. Electromechanical sensitivity is estimated and discussed using Taguchi orthogonal arrays for the factors, such as content of active filler and curing agent, mixing time in roll mill, curing temperature. Permittivity of the composites increased 6 times when compared with the sample without active filler. Electromechanical sensitivity of the composite improved 2 times, thus highlighting that this approach could lead to development of newer dielectric elastomer transducer materials.

Effect of Cobalt Stearate and Vegetable Oil on Uv and Biodegradation of Linear Low-Density Poly(Ethylene)-Poly(Vinyl Alcohol) Blends

2011 ◽  
Vol 2 (4) ◽  
pp. 131-148 ◽  
Author(s):  
Francis Vidya ◽  
Subin S. Raghul ◽  
Sarita G Bhat ◽  
Eby Thomas Thachil
Keyword(s):  
Vegetable Oil ◽  
Vinyl Alcohol ◽  
Water Soluble ◽  
Poly Vinyl Alcohol ◽  
Low Density ◽  
Compression Moulding ◽  
Melt Mixing ◽  
Degradation Behaviour ◽  
Moulding Process ◽  
Poly Ethylene

The main objective of this study was to enhance the rate of UV and biodegradation of polyethylene by incorporating biodegradable materials and prooxidants. Prooxidants such as transition metal complexes are capable of initiating photooxidation and polymer chain cleavage, rendering the product more susceptible to biodegradation. In this work, the effect of (1) a metallic photoinitiator, cobalt stearate, and (2) different combinations of cobalt stearate and vegetable oil on the photooxidative degradation of linear low-density poly(ethylene)-poly(vinyl alcohol) (LLDPE/PVA) blend films has been investigated. For this, film-grade LLDPE was blended with different proportions of PVA. PVA is widely used in the industrial field, and recently it has attracted increasing attention as a water-soluble biodegradable polymer. Cobalt stearate and vegetable oil were added to the blends as prooxidants. The blends were prepared by melt mixing in a Thermo HAAKE Polylab system. Thin films containing these additives were prepared by a subsequent compression moulding process. The effect of UV exposure on LLDPE/PVA films in the presence as well as absence of these additives was investigated. Tensile properties, FTIR spectra, and scanning electron microscopy (SEM) were employed to investigate the degradation behaviour. It was found

scholarly journals Mechanical Characteristics of Aluminium Powder Filled Glass Epoxy Composites

2017 ◽  
Vol 12 ◽  
pp. 1-14 ◽  
Author(s):  
Pujan Sarkar ◽  
Nipu Modak ◽  
Prasanta Sahoo
Keyword(s):  
Mechanical Characteristics ◽  
Tensile Modulus ◽  
Epoxy Composites ◽  
Aluminium Content ◽  
Compression Moulding ◽  
Moulding Process ◽  
Aluminium Powder ◽  
Void Fractions ◽  
Aluminium Addition ◽  
Powder Addition

Mechanical characteristics of glass epoxy and aluminium powder filled glass epoxy composites are experimentally investigated using INSTRON 8801 testing device as per ASTM standards. With a fixed wt% of fiber reinforcement, glass epoxy and 5-15 wt% aluminium powder filled glass epoxy composites are fabricated in conventional hand lay-up technique followed by light compression moulding process. Experimental results show that aluminium powder as a filler material influences the mechanical properties. Density and void fraction in composites increase whereas steady decrease of tensile strength is recorded with aluminium powder addition. Micro hardness, flexural strength, inter laminar shear strength (ILSS) of 5 and 10 wt% aluminium content composites are improved compared to unfilled glass epoxy composite and with further addition of aluminium up to 15 wt% decreasing trends are observed. Glass epoxy with 5 wt% aluminium concentration shows the highest improvement. Tensile modulus for aluminium addition of 5 wt% decreases whereas 10 wt% aluminium filled composite shows improvement in tensile modulus. These are explained on the basis of material properties, void fractions and bonding strength among the constituents.

Experimental investigations and optimization of processibility of sheet moulding compound

2011 ◽  
Vol 31 (2-3) ◽  
Author(s):  
Bhaskara J.C. Babu ◽  
Sachin Waigaonkar ◽  
Amit Rajput
Keyword(s):  
Penetration Depth ◽  
Flow Behavior ◽  
Glass Fibers ◽  
Zinc Stearate ◽  
Experimental Investigations ◽  
Compression Moulding ◽  
Maturation Time ◽  
Moulding Process ◽  
Moulding Compound ◽  
Sheet Moulding Compound

Abstract Sheet moulding compound (SMC) is a combination of glass fibers and filled polyester resin. It is processed by a compression moulding process and finds extensive applications in structural, automotive, electrical and electronic industries. The compression moulding process is characterized by the flow behavior of SMC under heat and pressure in the press mould. This paper is focused on the prediction of ideal processibility conditions of SMC. The qualitative aspect of a properly thickened (matured) moulding compound could be seen from its tack-free nature, which was quantitatively calibrated in terms of penetration depth, measured by a specially constructed softness indicator. The weight (wt)% of calcium carbonate (CaCO3) as filler, magnesium oxide (MgO) as thickener, graphite (C) and zinc stearate [Zn (C18H35O2)2] (ZnSt) as lubricants along with the maturation time (Tm) were selected as process variables. Taguchi’s scheme of experimental design was adapted to perform the experiments. It was found that the higher levels of MgO and CaCO3 were favorable for a good penetration depth as well as a reduced maturation time. We have also found that a penetration depth of at least 5 mm was required for achieving good processability conditions of SMC. An optimization study was under taken to find the right blend of additives and fillers, at their minimal weights and in the least possible maturation time, to achieve the desired processability. This study is particularly useful in a production run to make moulded parts from SMC.

scholarly journals Electrical and Thermal Conductivity of Epoxy-Carbon Filler Composites Processed by Calendaring

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1522 ◽  
Author(s):  
Andrea Caradonna ◽  
Claudio Badini ◽  
Elisa Padovano ◽  
Mario Pietroluongo
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Hybrid Composites ◽  
Synergetic Effect ◽  
Multiwall Carbon Nanotubes ◽  
Carbon Filler ◽  
Aspect Ratios ◽  
Roll Mill ◽  
Mill Equipment ◽  
Noticeable Improvement

Electrical and thermal conductivity of composites which contain carbon-based fillers in an epoxy matrix were investigated. The fillers were dispersed in the liquid matrix by using three roll mill equipment. The filler/matrix mixture was cast in a mold and then cured, thus obtaining composite specimens. Multiwall carbon nanotubes, graphene-like nanoplatelets, and graphite were used as fillers and their effect on conductivity was investigated. Electrical and thermal conductivity were measured at different filler loads. It was found that the formation of percolation paths greatly enhanced electrical conductivity, although they were not so effective in improving thermal conductivity. The behavior of composites containing each single filler was compared with that of hybrid composites containing combinations of two different fillers. Results show that fillers with different aspect ratios displayed a synergetic effect resulting in a noticeable improvement of electrical conductivity. However, only a small effect on thermal conductivity was observed.

Effect of hybrid-SiO2 particles on characterization of EPDM and silicone rubber composites for outdoor high-voltage insulations

2017 ◽  
Vol 37 (7) ◽  
pp. 671-680 ◽  
Author(s):  
Hidayatullah Khan ◽  
Muhammad Amin ◽  
Muhammad Yasin ◽  
Muhammad Ali ◽  
Ayaz Ahmad
Keyword(s):  
High Voltage ◽  
Silicone Rubber ◽  
Hybrid Composites ◽  
Standard Procedure ◽  
Research Work ◽  
Dielectric Strength ◽  
Hybrid Silica ◽  
Roll Mill ◽  
Thermal And Electrical Properties

Abstract Ethylene propylene diene monomer (EPDM) and silicone rubber (SiR) are well-known polymers for high-voltage (HV) outdoor applications. In this research work, the effect of hybrid SiO2 (a mixture of 15% microsized and 5% nanosized silica) has been investigated on the mechanical, thermal, and electrical properties of EPDM and SiR composites. Using the ASTM standard procedure, the EPDM and SiR composites filled with hybrid silica were compounded by two roll mill and simple blending techniques, respectively. It was observed that with the addition of hybrid SiO2, the composites exhibited improved tensile strength of ~2500 kPa, reduced elongation at break, and enhanced hardness. The samples filled with SiR hybrid silica showed higher thermal stability and volume/surface resistivities relative to EPDM hybrid composites. However, EPDM hybrid composites showed higher dielectric strength of ~23.4 kV/mm as compared with SiR composites. From these characterization results, it can be suggested that SiR hybrid composites are more suitable for outdoor HV insulation applications.

Analysis of the Quality of Rapid Manufacturing Technology Based on the Silicone Rubber Mold

2013 ◽  
Vol 432 ◽  
pp. 253-257
Author(s):  
Xue Fang Chen ◽  
Jian Hong Du ◽  
Hong Wei Li
Keyword(s):  
Silicone Rubber ◽  
Manufacturing Technology ◽  
Curing Temperature ◽  
Rapid Manufacturing ◽  
Manufacturing Processes ◽  
Exhaust Port ◽  
Channel Distribution ◽  
Mold Making ◽  
Silicone Rubber Mold

The rapid manufacturing processes include making prototype mold, making silicone rubber mold and pouring parts. According to the study of rapid manufacturing based on silicone rubber mold, factors that impact the characteristics of products, the quality of surface and the accuracy of dimension are discovered. The curing temperature and time affect the properties of products. The smoothness of prototype surface, gate position, exhaust port position, channel distribution and pouring speed affect the quality of the products surface. The shrinkage of the material affects the accuracy of products dimension. Moreover, some measures and methods that improve the products quality also be illustrated.

Optimisation of location and dimension of SMC precharge in compression moulding process

2011 ◽  
Vol 89 (15-16) ◽  
pp. 1523-1534 ◽  
Author(s):  
Moo-Sun Kim ◽  
Woo Il Lee ◽  
Woo-Suck Han ◽  
Alain Vautrin
Keyword(s):  
Compression Moulding ◽  
Moulding Process

Direct Moulding of Rubber Granules and Powders from Tyre Recycling

2013 ◽  
Vol 371 ◽  
pp. 315-319 ◽  
Author(s):  
Fabrizio Quadrini ◽  
Denise Bellisario ◽  
Loredana Santo ◽  
Ivica Hren
Keyword(s):  
Tensile Tests ◽  
Compression Moulding ◽  
Moulding Process ◽  
Particle Properties ◽  
Bound Rubber ◽  
Sample Density ◽  
Rubber Particles ◽  
Moulding Pressure ◽  
One Year ◽  
First Time

SMART project (Sustainable Moulding of Articles from Recycled Tyres) is a research project financed by the European Commission with the aim of developing a new moulding process of granules and powders from tyre recycling without any addition of virgin rubber or linking agent. The so called “direct moulding” is a compression moulding process which is directly applied to rubber particles from tyre grinding. After one year of activities, the new moulding process has been deeply investigated and some results are reported in the current work for the first time. Rubber granules and powders were produced by GumiImpex (partner of the European project) thanks to different technologies: particles from tyre grinding and buffings from tyre machining. Different size distributions of rubber particles and buffings were used to produce rubber sheets with the size of 200x200x5 mm3at the temperature of 160°C and the pressure of 3 MPa by using aluminium moulds. Tensile specimens were extracted from the sheets and tensile tests were performed and related to sample density and particle properties. Rubber densities over 1 g/cm3have been reached for all the samples with ultimate tensile strength and maximum elongation up to 1 MPa and 80%, respectively. These mechanical data are very promising in comparison with properties of polyurethane bound rubber composites. Increasing moulding pressure and temperature would lead to higher mechanical properties, if necessary.

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