|
Silicone emulsion (water-based) coatings offer some features of solventless
and solvent-based coatings, and some unique advantages of their own.
Advantages:
-
Same premium release performance as solventless coatings
-
Uniform, low coat weights can be obtained on simple solvent coating
equipment
-
Can be used in size press operations
Disadvantages:
-
Wetting and drying process tends to stress the paper
-
Buckling, curling and cockling may occur
Thickeners can be added that allow emulsion coatings to be used on more
porous papers, previously considered unsuitable for silicone pressure-sensitive
release applications. Thickeners increase coating viscosity, which reduces
penetration and prevents rupturing of the emulsion film during drying.
Use emulsion coatings if:
-
Smoothness is secondary to paper cost savings
-
You need to use solvent-type coating equipment
Use solventless or solvent-based coatings if:
-
Maintaining paper smoothness is essential
Emulsion delivery systems have been used successfully with platinum and
tin-based cure chemistries.
|
Change
