painting polyamide

[clao784]

Hi, I sell plastic resins (polyethylene, polypropylene...) for
injection moulding. One of my customers makes high heels in polyamide
6 (nylon 6) and they want to paint it. I know that you can paint
polystyrene and ABS easy but painting materials as Polyethylene is
harder. I need to know how easily they can paint nylon and which
painting do you recomend.

Thanks, regards.

[Rolf Wissmann]

Polyamides like PA6 & 66 are paintable. Industrially painted PA-parts are automotive wheel covers, tank flaps or rear view mirror housings etc. PA6 is "easier" to paint than PA66, due to its lower crystallinity.

The plastic parts need to be molded without the use of surface active substances, like mold release agents and the like. For handling the plastic parts, perhaps cloves are needed. Prior to painting, the plastic part surface needs to be properly cleaned and/or optionally (flame,plasma,corona)-treated for optimal paint adhesion, which all depends on your customers requirements.

He could go for a "traditional" 2K Primer & 2K Hardener plus a 1K Topcoat or a 2K Topcoat plus 2K Clearcoat, like the paint systems sold by DuPont/Standox. More details are following:

http://pc.dupont.com/dpc/en/US/html/visitor/b/stx/home.html
http://www.standox.com/portal/
Plastics and how to finish them:
http://www.standox.com.au/standox/uk/en/pdfs/Standotheks/THK_Plastic%20Paint_GB.pdf
How to refinish plastics:
http://www.standox.co.uk/standox/uk/en/pdfs/Standotheks/THK_PlasticPaint_GB.pdf
Plastic paint recommendation
http://www.standox.co.uk/standox/uk/en/images/multimix/MMX_LFT_Ku_GB_24-9-07.pdf

Or he could go for electrostatic powder coatings as sold by Akzo Nobel/Interpon
http://www.interpon.com/en/default.htm
consiting of:
waterborne 2K conductive primer
waterborne primer surfacer
waterborne base coat
solvent borne 2K clear coat

He ought to contact one of those paint experts in order to find the proper paint system and references to experienced painting companies in your area ...