Right, but they sold their tape technologies and "recipes" to Ampex/Quantegy, as I understand the
history.

-- Tom Fine

----- Original Message -----
From: "John Haley" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Friday, April 05, 2013 4:51 PM
Subject: Re: [ARSCLIST] Sticky SHRED


> By the way, 3M is still very much in business. See http://www.3m.com/.
>
> John Haley
>
> On Fri, Apr 5, 2013 at 2:23 PM, Tom Fine <[log in to unmask]>wrote:
>
>> I think Dennis is bringing up a really important point. Sarah and Richard,
>> do you have any contacts with original tape manufacturer chemists, people
>> who were familiar with the "brew" of the tapes? Before these people die,
>> it's important to get information from them about what chemicals were used
>> in the binders. There's no "state secret" anymore -- all of those tape
>> manufacturers are out of business now (and I'm afraid, given how things
>> work, that corporate records detailing the "brew" are probably lost to
>> time). One rumor that's widely circulated is that sticky-shed stems from
>> American manufacturers losing access to whale oil, so something else had to
>> be used in the binder and unintended consequences ensued. I've also seen
>> this rumor denied by former 3M employees, but I don't think those people
>> were actual tape-brew chemists. It would be helpful to know these facts.
>>
>> On a related line of inquiry, there should be research about storage of
>> non-sticky tapes. My own first-hand experience with acetate and early
>> polyester tapes is that if you store them in too dry an environment, the
>> edges curl and the acetate tapes become very brittle. I can state
>> first-hand that you can improve playback on an acetate tape that isn't
>> vinegar-syndrome but is edge-curled by b-winding it (oxide out) and letting
>> it sit in a cool, somewhat humid but not wet environment for a few months,
>> then returning it to a-wind and playing it. I've had good luck with this
>> method with quarter-track acetate tapes, often able to make the left
>> channel mostly playable without extreme measures like putting gauze in the
>> play-head can. All of this backs up my theory that the very-dry storage
>> conditions recommended for sticky-era tapes are not appropriate for older
>> tapes and hasten the complete disintegration of acetate tapes because they
>> dry out and become so brittle that the oxide flakes off. As I've said
>> before, I haven't seen any science saying that super-dry storage conditions
>> has any effect on sticky-shed, the tapes still need baking and still go
>> back to sticky after they've been baked. So why ruin other tapes in an
>> ineffective attempt to "preserve" sticky tapes?
>>
>> -- Tom Fine
>>
>> ----- Original Message ----- From: "Dennis Rooney" <
>> [log in to unmask]>
>> To: <[log in to unmask]>
>> Sent: Friday, April 05, 2013 1:01 PM
>>
>> Subject: Re: [ARSCLIST] Sticky SHRED
>>
>>
>> Unless I have overlooked an important post on this topic or am
>>> misunderstanding something, what I find missing in this discussion is
>>> any comment on the number of different oxide formulations by both age
>>> and manufacturer that have been investigated with respect to binder
>>> hydrolysis. We know from experience that the phenomenon affects
>>> preponderantly those tape types manufactured after 1975, Earlier
>>> formulations exhibited other problems but were stable with respect to
>>> binder hydrolysis. If my surmise is correct, there is much further
>>> study to be carried out on the problem in order to discover
>>> preservation and playback strategies that are more than anecdotal..
>>>
>>> DDR
>>>
>>> On Thu, Apr 4, 2013 at 4:40 PM, Sarah Norris <[log in to unmask]>
>>> wrote:
>>>
>>>> Hi, Tom (and list):
>>>>
>>>> Please find responses below:
>>>>
>>>> Would you, for us non-scientists on the list, summarize Bradshaw's
>>>>>
>>>> thinking and the opposing view(s)? Please try to keep it in the realm
>>>> of what an English major or at least what a MLS major can comprehend.
>>>>
>>>> A more thorough description is in my post from April 2, but here's a
>>>> very abbreviated summary:
>>>>
>>>> Bertram / Cuddihy's model says baking works because it repairs the glue
>>>> that holds the media together.
>>>>
>>>> Bradshaw / Bhushan's model says baking works because it makes the media
>>>> and other degraded fragments hold hands for awhile.
>>>>
>>>> Do any of the theories you explored about what causes sticky-shed
>>>>>
>>>> reveal why baking times would be increasing as the tapes get older?
>>>>
>>>> The models summarized above answer the question, "Why does baking work?"
>>>> The question we're asking now is something closer to, "How are tapes
>>>> aging?" I think the first question probably is relevant to the second
>>>> question, but probably not in a direct, straight-line kind of way. It
>>>> makes logical sense that longer required baking times indicate more
>>>> advanced degradation. Is that really the case? Now might be a great
>>>> time for a series of studies, one every few years, comparing required
>>>> baking times with degraded binder in tape samples!
>>>>
>>>>
>>>> Sarah Norris
>>>> Conservator
>>>> Texas State Library and Archives Commission
>>>> phone: (512) 463-5446
>>>> fax: (512) 463-5430
>>>> e-mail: [log in to unmask]
>>>>
>>>
>>>
>>>
>>> --
>>> 1006 Langer Way
>>> Delray Beach, FL 33483
>>> 212.874.9626
>>>
>>>
>