THE QUESTION OF RECYCLING

   Most people believe that plastics are easy to recycle.  You just melt the plastic and reform it, right?  What about the additives in the plastics that determine their physical properties?  For example, one company may produce a plastic with a viscosity of X poise and another produces the same plastic with a viscosity of Y poise.  If you mix the two (or usually several) plastics together when melting, you get a polymer that behaves differently from any of the original plastics.  In short, simply melting and reforming is very difficult and certainly more expensive than producing virgin material with predetermined physical properties.  So, what recycling options do work?
    Chemical recycling involves the breaking down of polymers into their fundamental parts being monomers and raw chemicals.  These chemicals can then be purified and reused.  But, like many great ideas in the industry, it is more expensive than producing virgin material.
    The other recycling option, material recycling, is what most people think of when they hear the word "recycle".  Old plastics are ground into powder or small particles and is mixed with virgin material.  A typical ratio of recycled to virgin material may be 1:10 or 2:10.  The reason that such a small percentage of recycled plastic can be mixed with new material is that the recycled material causes deterioration of the polymer mechanical properties.  So, although savings in raw material costs result, the product is of lower quality and may be less valuable.
    Recycling plastic is difficult, but it is done.  Millions of dollars in research are dedicated to this topic each year.  As plastic demand continues to increase, it becomes more and more imperative that an effective means of recycling be found.  Ironically, I believe that chemical recycling will ultimately be the answer for most plastics.  But first, science will have to find a way to make chemical recycling as cost effective as producing virgin material.  In order for that to happen, researchers will have to develop better ways to breakdown the world's most popular plastics.