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Old 22-Dec-2005   #3
weeijk
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Join Date: Nov-2004
Location: Apeldoorn
Country: Netherlands
Posts: 824
Quote:
Originally Posted by rockm
Nice idea and execution of it.

Polystyrene, however, is a very unstable plastic to use for bonsai applications. It breaks down pretty quickly, especially out in the sun. UV rays disintegrate polystyrene quickly. first it fades, then it crumbles. This can take a couple of months to a year. Sooner or later, though, it will crack, crumble or turn to whitish dust.
Correct, further when you want to make a cut or so, it becomes white aswell on edges. (Like when you bend a plastic coffee cup.)

Quote:

UV unstabilized plastic isn't the best material for slabs.
Thats why I will use UV stabilized coloured "masterbatch" (little pieces of plastic with high amount of pigment (40-50% and additives like UV stabs). Normaly the "masterbatch" we make in our plant has sunlight exposure values which are guarantied for 10 years. The "masterbatch" is than mixed with blanc Polypropyleen in an amount of 2-3% and melted. With the melted substance of about 200 degrees C, I create the slab.

This is probably too far down in the material for some, but after all, its my job.

Hope this will clearify some questions,

Wessel
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