Hi Valerie,
Valerie: Interestingly, IPC 4101 does not require any Tg testing. For Tg it 
states
that those are "optional tests as agreed upon between user and supplier",
and they reference both TMA and DSC as "the tests" for Tg.
EW:  That is one of the reasons that I have voted 'Negative' on the 4101 B
revision. The prime reason is the wide ranges of properties allowed on
each slash sheet. The problem is, that too many vendors in the committee
have too mch vested interest. We need to think more in terms oof 'Win-Win'
scenarios.
Valerie: At this point in time what little respect I had for the slash
sheets is totally gone. As far as I am concerned they are useful only in
the most general sense to differentiate one "family" of materials from
another; ie: polyimide vs epoxy or fiberglass reinforced vs aramid fibers,
and all the other permutations. Which means effectively that the only
portion of the slash sheet that has any value is the "description fields"
above the solid lines. Ok, maybe I exaggerate a little.. and I did go on
for a bit on this topic. If anyone thinks that specifying a slash sheet
means that they have "quality" material or "suitable" material, they are
mistaken. All they have done is describe the generic resin and
reinforcement; after that, it means almost nothing with regard to
performance and use.

EW: That is exactly my point. If the two of us can see that, where is 
everybody else? The committee voted "NOT ACCEPTED" on all of my suggested changes and 
want me to withdraw my "NEGATIVES."
Everybody, let Doug Sober <[log in to unmask]>, committee chair for 4101, 
know, if you agree-—lets swamp him [actually, he is a nice guy].



Werner