Curing of sealants (Silicones, Polyurethanes and MS Polymers) depend on two key factors, presence of humidity and bond line thickness. If humidity in the environment is low, sealant will cure very slowly.It is recommended to us a humidity oven/chamber to expose maximum moisture. In case of complex design or enclosed chamber where direct exposure of moisture is prevented, curing can get affected. A humidity chamber can help.
Because sealants cure in presence of moisture,thicker beads take time to cure.Top 2mm layer can cure in roughly 24hours,subsequently every 1mm thickness takes anywhere around 24hours. Thus sealants forming more than 2.5mm thickness will take time to cure and must be considered appropriately for a high speed production line.
Most sealants can be dissolved using Loxeal CR5 cleaner that also works very well on modified epoxy adhesives.
Dispenser choice depends on the viscosity of the product. A higher viscosity will need dispenser with high advantage ratio (typically 18:1 or more) and lower viscosity can be handled with dispensers of lower advantage ratio (12:1 or less).
