Fortified rosin soaps

Fortified rosin can also be converted to high free-rosin emulsions by using various stabilizers. Typically, these are 35% soHds emulsions, which exhibit exceUent stabiHty in relation to storage and mechanical action, such as is found in transfer pumps. Generally, fortified rosin emulsions are more efficient sizes than their soap-based Hquid or paste counterparts. 

Since the early days of machine made paper in the first half of the nineteenth century, the most widely applied method of Internal sizing has been the use of naturally occurring resinous materials ("rosins") in conjunction with an aluminium salt, usually aluminium sulphate (called "alum" by paper-makers). Various forms of rosin sizes (rosin soaps, rosin emulsions, fortified rosins) have been developed over the years to improve the process, but these variants still involve the use of alum as a means of ensuring that fibres retain a layer of size. 

Figure 3B.22 Internal paper sizing using rosin and fortified rosin. (Hubbe, M. Rosin Soap Size, Mini-Encyclopedia of Papermaking Wet-End Chemistry, BioResources, NC State University, Dept of Forest Biomaterials, Raleigh/USA, http //www4.ncsu.ed u/ hubbe/SOAP.htm iv/f/) kind permission.)...

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