Common Applications of Wiped Film Stills: Polymers

This week I would like to discuss some of the common applications of wiped film stills. 

For starters, let’s talk about polymers.

A technical discussion of wiped film still usage in the world of polymers would fill much more than a short post.  A book could be written on all of the various ways a wiped film still can be used in polymer production.  This post will be a brief overview of the topic. 

If you have a specific application you would like to discuss, please reach out.

Wiped film stills are commonly used in the following ways:

Solvent/Degassing removal:  Using a wiped film still is an efficient way to remove solvent from a polymer fluid.  Because the polymer is wiped into a thin film, the equipment is capable of removing residual solvents to levels lower than 1 ppm.  This is often needed for space age elastomers and polymers.  These glues and gaskets need to have all volatiles removed in order to experience the vacuum of space without a loss of functionality.

Monomer purification:  Wiped film stills can be used to produce extremely pure monomers.  These monomers can be distilled away from heavier impurities.  The purer the monomer is prior to polymerization, the purer and more valuable the product.

Monomer removal:  Monomers can also be removed from the polymer product by distillation.  One example of this is the removal of the cyclic starting materials from silicone polymers.  When a wiped film still is used, the residual cyclics can be reduced to less than 50 ppm in many cases.

Fractioning:  A lot of times when polymers are produced, a huge range of chain lengths is made.  Wiped film stills can be used to separate the polymers by size.  The shorter ones are collected as distillate and the larger ones are left behind.  Then those streams can be used in different applications as needed.