CONSIDERATION OF ADHESION TO MODIFIED CONTAINER WALLS, BY USE OF SURFACE-ENERGY AND POLARITY DATA, AND LEWIS ACID-LEWIS BASE INTERACTIONS

It is acknowledged that the labelling of pharmaceutical products is es sential on legal and ethical grounds. The desirability of using high s peed filling operations for large bulk liquid products, has resulted i n the surface coating of bottles with lubricant films, to allow smooth er movement through the filling process. In this study the adhesion to bottles which have had one of two different types of lubrication trea tment is considered. Simple empirical testing demonstrates that certai n combinations of bottle coat and adhesive will result in adhesive fai lure (loss of label), whilst others are acceptable. The interaction be tween the adhesive and the bottles has been modelled using theories ba sed on surface energy data. Both the polar and dispersion view of surf ace energy components, and the concepts of viewing the polar contribut ion to surface energy as comprising of non-additive Lewis acid-Lewis b ase components (with particular reference to monopolar surfaces) are c onsidered. It was found that both methods of considering surface energ y data gave some indication of adhesive performance, but only the acid -base approach gave a method of correlating predicted behaviour with e mpirical use tests. It is probable that the acid-base approach is the more appropriate for general application.