Key parameters for good drying of water-based sealants
In the drying oven, there shall be a circulation of hot air between can ends. Hot air inside the oven shall be continuously renewed to reduce humidity. Temperature increase inside the oven shall be gradual in order to avoid sealant blistering.
The aim of applying heat over wet water-based sealant is not only to remove water, but also to accelerate cross-linking or film reticulation.
Importance of low residual moisture in the dry sealant film
Before the seaming operation, the residual moisture of the lined compound shall be low enough.
As a general rule, longer dwell times and higher temperatures assure less residual moisture and better adhesion and resistance of the dry film. In the case of inadequate drying in the oven, the evaporation of the remaining water may take several days, depending on storage conditions of the ends.