Canning and Fish Packaging Technology

Unit 12 - Additives in plastics

12.1.4.Brightness
Many plastics do not have transparency of glass but are off white or yellowish or translucent. In such instances, brightners are added to enhance appearance. They operate by observing incident radiation of suitable wave length converting it into radiation in ultra violet or upper visible part of the spectrum. Stilbene or thiophene are used at 0.01% level as brighteners.