In some cases, a suitable combination of
heat-seal coating and film contact layer may not exist, therefore necessitating the use of possibly
another film or orienting the layers properly in order to make a seal. With regard to processing the
materials, when using commonly available materials in the market, most tend to work well together
when applying heat through the lid stock to make the heat-seal coating flow while keeping the film
cool to preserve its dimension. Most compatible heat-seal coatings tend to flow and make good
contact with the film when heated to 150ฐC with post seal cooling. As mentioned before, try to avoid
the use of universal or “bell” shaped forming tools when forming blisters to eliminate many common
problems associated with sealing related to web dimensional stability, wrinkling, and stress.