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No description available.

The imaging and graphic art industry is one of the higher GDP (Gross Domestic Product) generating industries in the UK. Generally, the quality of imaging and graphic art products depends on the properties of the imaging fluids, which are, in turn, determined by the physico-chemical interactions within the fluid, the imaging system and the imaging substrate. Despite the fact that the imaging and graphic art industry has been in existence for over one hundred years, it has thus far been difficult to understand many fundamental aspects of the physico-chemical interactions involved with the imaging process. To some extent, this has hindered the development of high quality imaging fluids, especially for more challenging imaging and graphic art work.

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