Shellac/vinyl mix compound LPs?

[paulfromcamden]

I noticed a note at the bottom of this release on Discogs from 1953:

This is a Norman Granz organized concert series. Boxset titled as #1. There are two 12" shellac/vinyl mix compound LPs.

I've never heard of this before but I do have a few early LPs that are made from something that doesn't feel quite like vinyl - somewhere between shellac and vinyl would indeed be a good way to describe it.

Are shellac/vinyl mix LPs really a thing?

 

[Vinny]

Compatible? Very very unlikely.

I don't know how shellac records were pressed, and cannot be bothered to Google, but I would bet quite a lot of ££££ (and more) that shellac is not a thermoplastic. (Just as a starter.)

Even if somehow you could get them to amalgamate and press, I would very, very much doubt that they'd stay that way long term.

I would also very, very much doubt that there were less than near countless different polymers tried in the early days of the transition shellac to man-made polymers, before a broad class of pVC/VA copolymers were selected as "best", which is what is used today.

 

[paulfromcamden]

Thanks Vinny. It sounded a bit odd - hence the question!

 

[Vinny]

I could be wrong, but it sounds totally nuts to me.

 

[paulfromcamden]

I found this article from 1952 which doesn't really answer the question but is an interesting insight into the early days 'vinylite' - it appears they were recycling old records into new records even then.

Stamping The Record

 

[Vinny]

it appears they were recycling old records into new records even then.

I am sure there must be one somewhere, but basically no industrial process, certainly of commodity products, could ever be viable if scrap could not be recycled within the process. No more so than anything to do with plastics - you cannot just throw trim away.
EVERY industrial process produces scrap. If it can't be recycled directly, there really needs to be an alternative use - in the vast majoirty of cases, you can't just "bury it".

 

[Marchbanks]

I think I’ve read about these dual-layer discs. With a standard stylus you can play the vinyl pressing on top, but with a special, very expensive audiophile needle you can reach down to the HQ hi-res shellac layer below.

 

[Vinny]

Shellac is a thermopolymer, amazingly enough - https://en.wikipedia.org/wiki/Shell...id, shellolic acid, and other natural waxes.

That said, like sticks to cehemically alike (and that applies to mixing/dissolving). Shellac is a mixture of long chain fatty acids, which are not at all like man-made polymers.

 

[guydarryl]

Shellac used as a binder/filler in PVC records perhaps?

 

[Vinny]

Shellac used as a binder/filler in PVC records perhaps?

Maybe????
Technically, shellac is a wax, so it might even plasticise PVC.

I found this article from 1952

I have skim read it and it has quite a few mistakes. Goodrich were the first company to find a way of processing PVC, whch had been known about for a long while previous. Goodrich added plasticisers. Records are made from an unplasticised filled (or not, but typically with carbon black), vinyl acetate/vinyl chloride copolymer.