Emulsion Particle Size and Distribution
Low quality ASA emulsions are not only less efficient, but also cause many paper machine operational problems. The performance of ASA size is directly related to the qualities of the ASA emulsion as it is applied to the paper furnish. ASA emulsion quality is affected by many variables. A primary dependency exists as a relation to the particle size of the colloidal ASA droplets. Particle size analyzers, using forward scattered laser light, reveal analytical details for emulsion particle size with its associated profile of the emulsion particle distribution. An emulsion with a mean volume (particle diameter) in the range of 0.5 -1.0 micron has been a widely desired target for the ASA emulsions. Measurably important is the shape (profile) of the emulsion particle distribution curve. Finer particle sizes with a narrow distribution profile are retained more efficiently and thus an emulsion with 99-100% of its colloidal ASA below 2 microns and a standard deviation less than 0.500 is the most effective.
Ordinary Turbine Emulsifier
|Mean Volume Diameter:||1.32µ|
|Particle Range:||0.133 TO 4.241µ|
NORCHEM Turbine Emulsifier w/ATS
|Mean Volume Diameter:||.698µ|
|Particle Range:||0.223 TO 1.26µ|
The graph on top illustrates an ASA emulsion processed through a conventional turbine emulsifier. The second graph illustrates the same emulsion chemistry processed through the NORCHEM AP series emulsifier adjusted for optimum size and distribution qualities.