Josh asks:
“Are pin adhesion tests a valid quality check for determining the quality of the Liner-Medium Bond?
If so, what would be the expected Force/Separation values for the common board grades?”
If properly performed on conditioned board according to TAPPI Test Methods, yes, it is a very good quality measurement and one I recommend. I like a target of 55 to 60# per linear inch. However, my peers say that any bond above 45# is considered good. The jury is still out in my mind! You should find that the single facer bond is generally lower than the double back bond.
What has been your experience?
If anyone else would like to share their experience or thoughts, please feel free to post your comments here.
– Ralph
askralph 
November 15, 2017 at 11:41 am
Ralph,
In regards to your comment on the DB measuring higher than the SF… What, in your opinion, would be an acceptable delta?
I have been conducting PINS and the results average ~25# difference between the DB and the SF… 58# to 33#
You thoughts?
-Kevin