[Coco] [Color Computer] Remove case yellowing

[jdaggett at gate.net]

On 6 Feb 2009 at 0:25, Sean wrote:

> So, I'm pretty sure the 80's and early 90's plastics yellow are due to
> how much sunlight they got.  Sometime in the 90's,  someone figured
> out a new formula, because there is a lot of equipment that has
> managed to stay the same color.

There are two basic types of plastics, thermoplastics and thermoset. 
Thermoset plastics are became less desirable as the Green Movement 
gained momentum. The major hinderence to thermoset plastics is the lack 
of reuse and recycling. Thermosplastics can be melted and reused more 
easily. 

All plastics breakdown under UV light. They need stabilizers to keep 
them from doing so. Nylon is propbaly the worst in UV exposure. Also all 
plastics outgas or leach chemicals into the atmosphere. That outgassing 
can react with other chemicals in the atmosphere and in the pigments that 
are used to color the plastics to discolor the surface. 

With the increase usage, and the demand for, of recyclable of plastics 
some types have fallen off in usage while others have gained in usage. 
Polycarbonates, Polyethalines are now very common in modern uses. 

james