Modification of Polypropylene by overtreatment by plasma
Modification of Polypropylene by overtreatment by plasma
(OP)
Hi
I am trying to understand what kind of physical change in polypropylene are caused by Plasma treatment.
I have to bond PP using adhesive (mostly CA) and using different settings I can get more than 48 or more than 60 Dyne/cm.
With the highest setting the material has a shiny shadow and when the adhesive bond is tested (for instance using a termal shock test) it fails.
I have some theories and I would like to know if I am on the right path: I think that an over treatment with plasma causes the material to be more brittle and probably some localized skrinkage that then comes into play when the assembly is tested, am I right?
Do you have any idea on the right test to check for this material characteristic changes and so define a treshold, be able to sample production, be able to controll the process better?
Thank you in advance
Paolo
I am trying to understand what kind of physical change in polypropylene are caused by Plasma treatment.
I have to bond PP using adhesive (mostly CA) and using different settings I can get more than 48 or more than 60 Dyne/cm.
With the highest setting the material has a shiny shadow and when the adhesive bond is tested (for instance using a termal shock test) it fails.
I have some theories and I would like to know if I am on the right path: I think that an over treatment with plasma causes the material to be more brittle and probably some localized skrinkage that then comes into play when the assembly is tested, am I right?
Do you have any idea on the right test to check for this material characteristic changes and so define a treshold, be able to sample production, be able to controll the process better?
Thank you in advance
Paolo





RE: Modification of Polypropylene by overtreatment by plasma
RE: Modification of Polypropylene by overtreatment by plasma
Cheers Paolo
RE: Modification of Polypropylene by overtreatment by plasma
Your joint fails because the material you are bonding to is degraded and weak. Plasma treatment is usually controlled to a certain dyne level. You can get dyne pens that are felt tip pens with different surface tension inks.
RE: Modification of Polypropylene by overtreatment by plasma
So it is not a surface tension test that I need but a material one to understand what changed inside the material, and how other properties are affected.
Thanks
Paolo