Search results for " Rubber"
showing 10 items of 113 documents
The effect of a liquid CTBN rubber modifier on the thermo-kinetic parameters of an epoxy resin during a pultrusion process
2003
Abstract Rheo-kinetic behaviour of an epoxy resin, coupled with an anhydride hardener, with different CTBN liquid rubber concentration (0–15 phr), used in fibre reinforced plastics, was analysed comparing experimental data with theoretical models. The modelling of technological pultrusion process for thermoset matrix composites, developed through a numerical code realised with MATLAB, is reported, too. The model includes conduction and cure heat, degree of cure and viscosity evolution during the curing within the die. Considerable differences in process condition, using different rubber amount, are obtained. The numerical modelling of process conditions shows that the CTBN rubber presence i…
Effect of curing time on the performances of hybrid/mixed joints
2013
Abstract The aim of this work is the study of a mixed method used for the joining of aluminum alloys with glass reinforced polymer’s substrates (in the next GFRP). In particular, the technique of self-piercing riveting (in the next SPR) was applied on a co-cured joint in order to evaluate the influence of the time of inserting the rivet on the mechanical behavior of the mixed joints. Three different joints were realized: adhesive by co-curing technique, mechanical by self piercing riveting (in the next SPR) and a mixed one in which the joining techniques (i.e. adhesive and mechanical) were combined. In particular, to determine the optimum time to insert the rivet, three different times from…
Evaluation of the fracture performance of different rubberised bitumens based on the essential work of fracture
2017
The fracture performance of rubberised bitumen in addition to one pre-treated with a Warm Mix Additive (Sasobit®) was investigated using different test methods measuring different damage mechanisms. Two Recycled Tyre Rubber (RTR) modifiers together with two base binders were blended in the laboratory to produce various combinations of Recycled Tyre Rubber Modified Bitumens (RTR-MBs). The first RTR is a standard recycled polymer derived from discarded truck and passenger car tyres by ambient grinding. The second RTR consists of 100% recycled truck tyres derived by cryogenic grinding and pre-treated with special oil and WMA to allow further decrease of asphalt mixture production temperatures.…
Sheet metal forming of titanium blanks using flexible media
1998
Abstract Sheet metal forming processes using flexible media are increasingly utilized in the industrial practice due to the relatively low tooling cost. In the present investigation, a rubber forming process is applied to the manufacturing cycle of a titanium alloy component for acoustic tweeters. The proposed process allows a reduction in manufacturing costs and production time since it permits the elimination of some joining operations. The FEM analysis has permitted the definition of the optimal process parameters and tooling geometry. Accordingly, several components have been produced; the achieved quality level is comparable with the one obtained utilizing the conventional technology a…
Effect of a Compatibilizer on the Morphology and Properties of Polypropylene/Polyethylentherephthalate Spun Fibers
2017
Fibers spun by melt spinning of binary and ternary polypropylene/ polyethylenetherephthalate blends have been produced and characterized in order to investigate the effect of a compatibilizer on their morphology and mechanical properties. The compatibilizer was a maleic anhydride-functionalized rubber copolymer. The effect of the compatibilizer was well evident in the isotropic state, as the morphology became very fine, the size of the dispersed particles was very small, and the adhesion was better. The effect of the compatibilizer on the mechanical properties is very relevant, especially in the elongation at break. On the contrary, no relevant effect was observed in the anisotropic oriente…
Mechanical characterization of dry asphalt rubber concrete for base layers by means of the four bending points tests
2012
The mechanical characterisation of the asphalt concrete in terms of both the fatigue resistance and the stiffness modulus is necessary to use any design method of the flexible road pavements. Even more the determination of these mechanical properties is necessary if the asphalt concrete investigated is an innovative material as a dry asphalt rubber concrete DARC (i.e. a bituminous mixture with rubber via dry process). Such material is less known and investigated than the asphalt rubber concrete via wet process, even if its application implies peculiar economical and environmental advantages such as no specialized equipment or significant plant modifications and large quantity of recycled wa…
A theoretical approach to pneumatic muscle mechanics
2013
The mechanical response of pneumatic artificial muscles is analyzed assuming the inextensibility of the sheathing braids and taking into account the stress field inside the rubber bladder, which is regarded as a Mooney-Rivlin hyperelastic material. The end effects are simulated by heuristically profiling the meridian section. After estimating the constitutive parameters by traction tests on rubber specimens, the theoretical results are compared with experiments and a satisfactory accordance may be detected.
Formulation, Characterization and Optimization of the Processing Conditions of Blends of Recycled Polyethylene and Ground Tyre Rubbers: Mechanical an…
2005
Abstract Recycling represents a valid alternative to the disposal of post-consumer plastics in common landfills if it is possible to obtain new materials with good final properties compatible with practical application and, above all, by using cheap methods. In this work the possibility to produce secondary materials by blending recycled polyethylene (RPE) coming from greenhouses and post-consumer ground tyre rubber (GTR) has been studied. In particular, the preparation of these blends has been carried out in a common industrial twin screw extruder. RPE pellets and GTR powder were fed to the extruder without any other additive. Temperature, processing speed, mixing procedure and composition…
Study of methyl methacrylate polymerization in the presence of rubbers
2001
Grafting of poly(methylmethacrylate) onto various unsaturated rubbers is described. The grafting is achieved through thermally initiated methylmethacrylate in-situ polymerization. The main features of the polymerization process, i.e. conversion vs. time, grafting to rubber and gel percentage, have been investigated. The chemical structure of the rubber influences the process: rubber with pendant unsaturations gives rise to higher level of grafting.
Submicron structured polymethyl methacrylate/acrylonitrile-butadiene rubber blends obtained via gamma radiation induced ?in situ? polymerization
2004
The morphology and properties of PMMA/rubber blends, obtained through gamma radiation induced “in situ” polymerization of methyl methacrylate (MMA) in the presence of small quantities of an acrylonitrile–butadiene based rubber (ABN), are presented. Different systems have been obtained by irradiating at a fixed irradiation dose rate and temperature, varying the integrated dose. All the blends obtained were characterized with respect to their melt state and solid state dynamic-mechanical response and mechanical tensile properties. In particular, the effect on the blend properties of prolonging the irradiation time was investigated. Furthermore, a morphological characterization through atomic …