A method to predict % cure of E-beamed coatings

An electron beam can be used to cure a material which has been coated on a moving web. The main purpose of this report is to develop the necessary equations and a general procedure to predict the extent of cure of these coatings. Special emphasis is placed on thin film coatings below 1,000 angstroms. The calculation of the % cure is based on a knowledge of the electron beam chemical event cross section of the material. The general procedure to measure this cross section using an industrial electron beam machine is discussed. Then, the measurement of an oligomeric diacrylate cross section is presented as an illustrative example. The acrylate's chemical event cross section is found to follow the disjoining pressure effect, i.e., a dependence on coating thickness for thin film coatings below a few thousand angstroms. Once the cross section is measured, the results are then successfully applied to the prediction of the extent of cure of the acrylate at various coat thicknesses. (author)