Any machineable plastic optically clear after machining? 1

[13]

Does anyone know if there are any machineable plastics that come in tube form retain their transparency even after machining?

No polishing steps preferred.

Thanks in advance.

 

[MikeHalloran]

Acrylic (PMMA) comes in tube form in a lot of sizes, and is nicely machinable. If you use kerosene as a coolant, generous nose radius, razor sharp edges, and fine feeds, you can get an optically decent surface without polishing.



Mike Halloran
Pembroke Pines, FL, USA

 

[Compositepro]

When you machine anything you will be left with a machine finished surface. If you need a very smooth surface for transparency you must use a fine finishing operation which is usualy called polishing. Some plastics can be fire polised like glass. Others that are soluble in solvent can be polished with a quick dip in solvent.

 

[13]

Thanks, I appreciate your input and attention to detail!

 

[MikeHalloran]

I guess the solvent dip works for some people. For me, it usually causes the part to crumble like tempered glass, a month after the dip.



Mike Halloran
Pembroke Pines, FL, USA

 

[patprimmer]

As Mike says about acrylic, but I think you will need to polish it. Flame polishing is effective for final polish.

Cellulosics can be machined and solvent polished. They are not so sensitive to solvent stress cracking as most other clear plastics. They melt fairly easily and are a bit rubbery, so care needs to be taken when machining them.

Regards

eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[unclesyd]

Here are the materials, Micro-Mesh, for polishing essentially any plastic.

https://www.micro-surface.com/default.cfm?page_id=1

 

[opticsman]

Hello. You could also try coating the machined material with a clear lacquer or clear polyurethane paint. Spraying will be best. This layer will tend to make fine scrathes dissapear. Of course the final appareance it will depend on how good the original machine finish is.
Opticsman.