All thermoplastics creep, even GF filled ones. You need to know the load, time and temperature and then get a set of creep curves form the manufacturer. The question isn't whether it will creep, it's how much. How much deflection can you handle?
Amorphous polymers creep less than...
ABS pipe solvents contain ABS. The solvent penetrates the ABS at the surface and the polymers tangle on both parts and the solvent. Then the solvent (MEK, I believe) evaporates and you get a great bond. Your homes sewer lines are all ABS that are solvent bonded.
You could use laser welding if...
Nylon 6 flows better than nylon 6,6. Glass fiber will only make it more difficult to fill thin walls.
Liquid Crystal Polymers are the king for thin wall molding.
Looks like classic solvent exposure in PC. The silicone outgasses alcohols and possibly other solvents that could be the source or the adhesive tape under the light strips could be the culprit if there's adhesive tape in there.
Only amorphous thermoplastics are clear. That leaves you with...
In semi-crstaline polymers like PA66 and PA6, you can improve the surface finish with higher injection speeds. Increased mold temps help more with amorphous polymers like PC, ABS, PS, etc.
You will find that PA6 has better surface finish than PA66 primary because it flows better (lower...
