Knowledge base

IntroductionEnvironmental and safety problems (solvent emission,energy consumption, flammability) associated withsolvent based pressure sensitive adhesives (PSA) haveintensified the, development of and conversion toalternative technologies in the last ten years e.g.emulsion and holtmelt PSA.These systems do not always offer all the properties ofthe

IntroductionRadiation curing is of particular interest in the packagingindustry because this industry is noted for its rapid growth intechnological adcances. It started in 1969 when the first commercialrun of UV—curing inks and varnishes were tested on afolding carton line in the United States[1].Since then only a couple of reports on UV-flexo inks

IntroductionOver the last few years, the surface caotings industry has seana rapid increase in the use of radiation curing. [1] The mostcommonly used materials in conjunction with radiation curing areacrylates. These materials are polymerised by afree radicalchain process which in uv. curing is triggered by the use of aphotoinitiator and in the cas

IntroductionThe application of radiation curing has, until now, been son ewhat restricted by limitationsinherent in the chemistry of free-radically initiated acrylates. As a result the penetration ofthe coating industry by radiation curing lags behind that achieved by the other so-called "new"coating technologies. The cationically initiated epoxide

IntroductionThe techniques for 'the inerting of ali electron beam processor have developed quiteslowly over the past two decades. The requirement of an environment of low oxygenconcentration in which to initiate and complete the addition polymerization processefficiently has been a severe impediment to the industrial use of the technology.Due to th

INTRODUCTIONMost materials capable of photopolymerizatiàn contain initiatorswhich are sensitive only to light at a wavelength below 430 nm.These materials can be processed without difficulty under daylight,conditions, of course; however, a portion of the radiation emittedin'the visible range of the usual types of light sources (e. g.high pressure m

IntroductionThe ultra violet curing of pigmented surface coatings is now well established in the litho and screen printingsectors of the graphic arts. In these systems the pigmentsthemselves cause considerable constraint by absorbing uvirradiation and competing with the photoinitiators for theavailable energy. The darker pigments, blues and blacks

INTRODUCTIONAcrylate oligomers and monomers are very reactive as a class of materials.Because of this reactivity there is apossibility of serious consequences if these materialsare improperly stored or handled. Unfortunately, very little information is available onthe behavior of these specific materials. The purpose of this study was to perform a