Canning and Fish Packaging Technology

Unit 12 - Additives in plastics

12.1.1.Anti block agents
These films especially if they have a smooth surface without irregularities tend to stick together, a process which is referred to as blocking. This can cause difficulties in handling processing and sometimes during packing operation.

Antiblock agents overcome blocking by producing microscopic roughness. Such additives are normally very fine powders of low solubility in the plastic. The most common antiblock agent is finely divided silica in the size range of 1-7 micron dia and the concentration range from 1-6 ppt in plastic.