Papers by Keyword: Silicone Rubber

Abstract: This work reports on mechanical and thermal properties of a novel polymer blend. Blends were prepared by mixing silicone rubber with diphenyl – 4,4 – dissocyanate in different ratios. Graphene nanoplatelets was added as conductive filler to improve the electrical conductivity of the blends. The mechanical properties, including tensile and tear performances were measured by a material testing system. The thermal stability of the blends was measured by thermogravimetric analysis. Incorporation 20 vol.% of silicone rubber can help to improve the thermal stability of the blend, meanwhile optimum mechanical properties of the blends is achieved.

Abstract: The following paper indicates variants of new materials obtained with various organic alloy elements. Our research has used recoverable silicone rubber, obtained from used scrapped silicone rubber, used for the tyre of 24 kV composite electrical insulators as a basic matrix, under the form of silicone powder, liquid silicone rubber to various proportions, along with nanopowders obtained through recycling

Abstract: Uniaxial tension tests for filled silicone rubber were performed at high strain rates using a split Hopkinson tension bar system. Quasi-static tension tests were carried out using an Instron-E3000 material test system. The grip fixture was designed to reliably connect the tensile specimen with the incident/transmitted bars. The method to increase the signal-noise ratio of the stress pulse in the transmitted bar was proposed. The effect of specimen gage length-to-width ratio on the stress-strain responses was experimentally studied. The suitable specimen geometry was determined by means of experimental investigation and finite element analysis. The automated grid method was used to capture the deformation information of the tensile specimen. Experiments indicate that the tension responses of silicone rubber exhibit the apparent hyper-elastic and rate-dependent characteristics. The values of tensile modulus increase with the increase of strain rate. The stress at a given elongation increases with the increase of strain rate.

Abstract: Electronics devices consist of silicon chips, copper leads, resin or ceramics substrates and which are jointed to each other with solder, conductive adhesive or other materials. Each coefficient of thermal expansion is different and it causes strain concentration and cracks. The solder easily deformed by the difference of the thermal expansion and it relieved the stress on the devices however the epoxy resin of the conductive adhesives are harder. So we suggested the composed joint including the relaxation layers of low elastic material. The shear strength and elongation of the epoxy resin joint, silicone rubber joint and the composite joint of the two materials were investigated. The analytical study was carried out to clarify the stress reduction effect of the design of the relaxation layer in the composite joints. The parameters such as the width, height, pitch and the distance of the relaxation layer from the joint edge are investigated. The high relaxation layer close to the joint edge effectively reduced the stress of the joint. The stress reduction effect appeared in the different pitch of the layers.

Abstract: Silicone rubber composites filled with fused silica were prepared through sigma mixing followed by hot pressing. Filling fraction of fused silica in the silicone rubber matrix was varied from 0-0.51 volume fraction (V_f) and its effects on dielectric properties at different frequencies, thermal properties and moisture absorption were investigated. The results indicate that with the increase of filler volume fraction the relative permittivity increases and dielectric loss decreases. The coefficient of thermal expansion decreased and the moisture absorption increased marginallyas the filler loading increased.

Abstract: This paper presents the results of a study carried out to examine electrical characteristics of high voltage Silicone Rubber (SIR) insulators under weather pollution conditions. The specimens of SIR with and without Alumina tri-hydrate (ATH) filler have been chemically prepared. The AC (50 Hz) surface aging of SIR specimens have been evaluated under salt fog chamber. Furthermore, the relationship between the leakage current and time to failure for SIR specimens with various concentrations of ATH filler under different weather pollution conditions has been measured in this work.

Abstract: A flame-retardant room-temperature vulcanizated silicone rubber (RTV) was prepared with the addition of APP. The effect of different amount of APP on flame retardance, tensile properties, and thermal stability of RTV were studied.Results showed that RTV/APP composites possessed better flame-retardant behaviour, better initial thermal stability, but worse tensile properties.

Abstract: Design and fabrication of an object with parts embedded internally within the part has always been a difficult challenge to fabricate. This is mainly due to limitations in design for manufacturing (DFM). The objective of this work is to investigate improvements in overcoming limitations in DFM of non-metallic object with embedded part within a part through 3D printing technology and silicone rubber. 3D printing technology is a type of Rapid Prototyping (RP) method which has limitations in its material durability and product failure rate. This technology combined with silicone rubber is envisaged capable to overcome some of the limitations in DFM while increasing its durability. Layer manufacturing using 3D printing is used to construct scaffolding of the end product and silicone rubber used as material to fill the cavities. The end product is a unique “one-piece” outdoor water-feature cage that has no assembly of parts between its various internal and external components which entraps a free rotating ball feature inside the cage. Both limitations in DFM of a part within a part and improving prototype materials durability had been overcome.

Abstract: Skin is an important organ which provides multiple functions. Thus, if skin fails i.e. due to burns or diseases, body will lose the protection provided by skin against infections and the harmful outer environment. Due to that, synthetic skin is seen as a very important alternative in the future. A number of studies have been carried out to understand skin’s basic functions and behaviour as its mechanical properties and behaviour are important in various fields. Nevertheless, to date no breakthrough has been reported. Therefore, this paper aims to briefly review and outline a framework which ultimately will lead to the synthesising silicone-hydrogel materials that potentially becoming a skin substitute. The newly synthesised composite materials will be tested mechanically to characterise its behaviour based on Ogden hyperelastic model. It could be emphasised that the present study is significant and will contribute to the body of knowledge in the area of skin mechanics.

Abstract: A large number of ceramic insulators that are widely used in the power systems are returning shipment every year but there is no better processing method. Silicone rubber insulators have highly required the additive of the formulation. So this article combining the advantages of ceramic insulators and chemical composition, studies the mechanical properties of ceramics modified composite insulator materials. The measurements include the tensile strength, tear strength, hardness, SEM and Fourier transform infrared spectroscopy test of the new silicone rubber. The effects of adding different proportions of ceramic powder on the mechanical properties of silicone rubber are compared. And from the microscopic analysis the mechanism of the improved properties of the modified silicone rubber is analyzed. The results showed that a proportion of the ceramic part can replace aluminum hydroxide powder and the fumed silica powder can significantly improve the mechanical properties of the silicone rubber.