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Posted: Wed Jun 09, 2010 1:38 pm
by Richuk
What about using a dyne pen to work out any kinks that arise from using different equipment?
Posted: Thu Jun 10, 2010 10:12 am
by Damon
Richuk wrote:What about using a dyne pen to work out any kinks that arise from using different equipment?
You could, but really most of us don't need to be that advanced. Really would could just sprinkle some water on and see if it beads and that will be a reasonably good indicator of how well the treatment works.
Montucky, sorry if I sounded like an ass, didn't mean to word it like that. When you're flame treating, you are breaking molecular bonds in the polymer. The bonds open up releasing hydrogen and attaching oxygen - from the environment.
Posted: Thu Jun 10, 2010 12:28 pm
by Richuk
I thought the following was correct:
Plastics that have low surface tensions (below 40 dynes/cm) generally cannot be adhered to easily. Surface tensions must be at least 38 - 42 dynes/cm to realize good adhesion. A surface tensions of over 70 dynes/cm can be achieved at which point water will moisten the surface completely and not bead. The higher the dyne level, the more robust the adhesive process becomes.
So if you're going to rely on water beads, you'll need a very small protractor ; )
Posted: Thu Jun 10, 2010 3:12 pm
by Damon
Agreed, but what I'm saying is the difference between a treated material and untreated in terms of water beading is pretty significant. Like obvious hydrophobic vs hydrophilic properties.
Posted: Mon Jun 14, 2010 3:57 pm
by Richuk
I've yet to attach a P-tex edge, but I thinking that pure Glycerol would be better than water, as it has a dyne value of about 63. It's cheap and you're more likely to get closer to the point at which it wets out and so results will be easier to interpret. I'll give this ago myself once I get this far

Posted: Mon Jun 14, 2010 5:17 pm
by threeninethree
Here is a source for dyne pens.. also interesting is a hand held corona treater. I may have to contemplate that... $415 though!
http://www.nbond.com/5543.html