Epoxy resins are widely used materials in the industry as electrical insulators, adhesives and in aircrafts structural components because of their high mechanical stiffness, strength and high temperature and chemical resistance properties. But still, the influence of water uptake due to moisture adsorption is not fully understood as it detrimentally modifies the electrical and chemical properties of the material. Here ,we investigate the influence of water moisture uptake on the neat epoxy material by monitoring the change in the volume resistivity and dielectric properties of epoxy material at three different thickness configurations: 0.250 mm, 0.50 mm and 1 mm thicknesses. Gravimetric analysis was done to monitor the mass uptake behaviour, Volume Resistivity was measured to monitor the change in conductivity of the material, and the dielectric properties were mapped to characterise the type of water mechanism available within the material during two ageing processes of sorption and desorption. Two-stage behaviours of diffusion and reaction have been identified by the mass uptake analysis. Moreover, the plot of volume resistivity versus mass uptake has indicated a non-uniform relationship between the two quantities. However, the analysis of the dielectric spectrum at medium range of frequency and time has showed a change in the dipolar activities and also showed the extent to which the water molecules can be segregated between bounding to the resin or existing as free water

This objective of this project is to develop an understanding of the ink and its interaction with substrate of Penny & Giles controls Ltd's conductive plastic potentiometers, so as to develop alternate ink, substrate and processing methods. Conductive plastic potentiometers comprises, a track containing polymer binder and carbon black, printed on a base plastic substrate. The objectives have to take into account the performance ofthe potentiometers, which are to be improved or maintained. The first stage of the project was concerned with investigating the properties of the carbon black used in the inks, which have a major effect on the performance of the potentiometers. Ten different carbon blacks with different properties were selected. The carbon blacks properties for most of these were characterised by techniques that included transmission electron microscopy, x-ray photoelectron spectroscopy, differential scanning calorimetry, laser induced mass spectrometry and the scanning electron microscope. Inks were made with most of individual carbon blacks, and then tracks were produced on the diallyl phthalate plastic substrate. The electric resistance of these tracks was measured allowing the effect of carbon black properties on performance of the track to be studied. Various carbon black were found to provide similar performance to the Vegetabke MR842N, carbon black used currently. The next stage was the investigation of effect of binder on the performance of resistor using the same techniques as used in the first stage so that comparison could be made with the current binder. A phenolic binder was used and again showed similar properties to the DAIP binder used currently

Introduction. A part of the standard testing procedure on high voltage cables is the measuring of the volume resistivity in the different semi-conductive layers. A need for improvement has been realized because of the increased frequency of testing, which is a result of the recent expansion of cable production of NKT in Karlskrona. Objective. The objectives of the thesis are to firstly discover what the needs are for improvements within the method of conducting volume resistivity measurements on high voltage cables. Secondly, following these discoveries, solving the problems by developing new products. Method. The method for the thesis work is divided into two parts, performing a case study on the current measurement method, and product development for the new solutions. The case study was conducted mainly by gathering empirical data through interviews and observations. The product development process started with ideation for solutions, followed by prototyping, and lastly, a validation process to test the new solutions through experiments and lead used testing. The entirety of the work was conducted through a design thinking approach. Result. From the case study it was discovered that two main issues needed to be addressed, being a new solution for a measurement rig, and a way to streamline the painting and taping process. A new design for a measurement rig was invented. The new solution contains two rigs, which allows for more samples to be heated simultaneously, halving the preheating time when testing four samples from the current measurement method. A preparation station was also created to aid the operators with the taping and painting, which resulted in a 40% reduced time for these tasks. Conclusion. By implementing new products, the measurement method for conducting volume resistivity has been improved by time effectiveness, robustness, and reliability.