Pat's answer is a good one and a sense of humour thrown in for free. Another approach might be to blend in some maleated PP (such as Exxelor 1020, Epolene, Orevac etc). That will give some polar sites to dye. Not sure if they will acid dye or not. Or simply oxidise the PP after the extruder with flame treatment or corona.
There is not any memory with less satisfaction than the memory of some temptation we resisted.
- James Branch Cabell
It's 40 years since I studied it, but acid dyes attach to the amide groups in wool or nylon.
They tend to block of from nylon when all the amide sites are occupied. I think the dyes are anionic and the amide groups are cationic, so creating any cationic groups will attract the dyes. Sometimes it is a problem with straight nylon to get the required depth of shade, so alloys of polypropylene will be even more difficult to dye to dark shades.
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.
