Thermal degradation of vinyl and its expected lifetime?

PVC used in records is slightly plasticized, meaning that an ingredient is added to make the pvc more flexible. i assume this enables it to hold a more detailed impression of the stamper groove. a PVC shower curtain or swimming pool liner would be an example of a highly plasticed PVC compound. over time these plasticizers can leach out of the PVC compound, causing it to become more brittle and less resiliant.

i would suspect the amount of this leaching depends on the original compound and the storge conditions. i'm not sure how it would affect wear, maybe the record groove would recover less from stylus heat and pressure over time.

 

Among our crowd, I'd suspect the biggest threat would come from how some approach cleaning their records. I saw a recommendation the other day on AudioAsylum for Spray & Wash (the laundry product).

Sometimes I wonder if somewhere down the line I'll end up unknowingly buying some LPs that've been cleaned with some sort of harsh chemicals or a homebrew solution that's leached a lot of the plasticizers from the vinyl.

 

You're welcome - I'm sorry, I don't really have time to look up the references. Google now has a search function for scholarly works (they call it "scholar") that will probably find some of them.

Alternately, use your library's database searches for similar articles - it might take a while to find what you want, and honestly this level of detail is not what I normally deal with or am all that familiar with. Best of luck!

Also, when you do your library trip, talk to the reference librarian and tell them what you are specifically looking for.

 

I already said that a OM-40 did play that same groove 48 000 times without ANY problems with warm vinyl.

 

first of all, your merely stating that is not proof (which you freely offered to provide)

secondly, even if that is a fact, it still does noting to dispute what you were calling "pseudo-hifi science"

unless there is a serious misunderstanding, I thought you were attempting to claim that because an LP is not warm after play, this somehow proves that the vinyl doesn't momentarily melt when in contact with the needle

since the vinyl quickly "un-melts" once the needle passes over (as stated before), there is no reason one might necessarily expect to find the LP "warm" after play

so unless I misunderstand you, please provide some actual proof that the needle in fact does not momentarily melt the vinyl as it passes over

if I have misunderstood you, please explain what you were saying is "pseudo-hifi science" and "IS NOT SO"

and check these links while you're at it

(bonus link from these very forums)

 

Regarding storage, I can give some anecdotal evidence that should give you some encouragement.

About 20 years ago, I got my first cd player and quit buying vinyl. In the next 3 years, I quit playing vinyl and then got married. Once married (marketing phase completed...), my wife determined that there was no point in having the lps anymore. I didn't want to get rid of them, so the solution was to box them up and to store them somewhere out of sight. From 1993 until this last December, the lps have spent at least half that time in our attic during Texas and North Carolina summers and winters.

Once the MMF-5 was set up this last December, I retrieved the boxes, fully expecting to see black vinyl dust where my records used to be. To my absolute delight, they all looked good - and played just as perfectly as they did when they were my primary source. Sure, there is the possibility that I might have shortened their life by 30 years or so, but that means that I have at least 50 more years to go.

 

You can't take it with you... although I'm sure some of you want to be buried with your vinyl

 

Now there's an idea! A casket with an outer layer made from the deceased's favorite lps! The only problem is that you'd be destroying musical treasures in the process of such a gesture. In the case of someone that you hated, you could cover the casket in Goldsboro's 'Honey'.

And now, back to your regularly scheduled thread....

 

Vinyl is not really that different than say thermoplastics or gutta percha or other compound material formed by heat and pressing - a material in common use by the mid-1800's by the way. After a lifetime of dealing with antiques and old (sometimes very old) items, one thing that can be banked on is this: storage means everything to preserving an item. The general rule - and you see this in the museum/curating and preservation/restoration fields - is controlled humidity and temperature and reduced exposure to outside light - to the extent possible.

I've had well meaning collectors and people tell me that rust is unavoidable on steel items as it ages. However they get speechless when I show them something made of steel from the mid 1800's that looks like it was made yesterday. Of course your typical mild steel will always be oxidizing and thus 'rust' - in a technical sense - that does not mean that an item can't last for a very long time if stored right and even retain a look that defies aging as we typically see it.

I have no doubt that records 'stored right' can & will last for centuries. Record vinyl I've been told, by a chemical engineer who once worked with vinyl, is a very inert, stable, and tough material.

The problem here is the encoded information is still stored on or in something that is going to have a 'life.' Who knows how long a run of the mill hard drive will last without degradation or change.

 

I really doubt that there is anything to worry about here. How long does it take for a StyroFoam cup to decompose...?

 

No need, I haven't seen ANY real proof that it should "temporary" melt.
And if so, playing a single groove over and over again would make it totally destroyed after a couple of plays. Or are you really telleing me that the needle are making the vinyl SO HOT that it melts a little, BUT that the warmth are gone in less than 2 seconds when the needle comes again?

 

actually, there is some need, since that proof is what you originally claimed you already had and were going to provide

were you were being less than honest?

yes, that is really what you have been told repeatedly

 

So that two sites are saying it, without ANY serious measurments, is proof enough?
Say it again, how can the vinyl go from 300 C to normal degree within 2 seconds? I don't want some links to sites without any real proof, just a good explanation.

 

I had a guy today tell me badly warped records wont damage the stylus cause its a needle.

this guy has been in business all his life and owns a record store and fixes turntables and tv's.

unless I am misinformed, is he right ? lol....

 

it was more than two sites, as you know

and it's certainly more proof then what you claimed you would provide, the amount of which has turned out to be absolutely none

but if you don't believe it happens, why don't you ask our host about it?

 

Still no proof. Again, can you tell me how it can drop from 300C to normal in 2 seconds?

 

Not sure if I understood. Does it means that vinyl has some kind of "memory"? You know like Flexon?

Helio

 

If this needle/groove melt theory is true - the heat would have to affect only the absolute surface of the groove. In other words, any 'melt' that would occur would have to be exceptionally shallow - measurable only in a micro defined increments - and nearly instantaneous.

 

I know, and we've been waiting since you first promised it at post#13

I gave you numerous links, including one that made it ridiculously easy for you to ask our host

so what are you bringing to this discussion besides broken promises and less-than-honest declarations?

 

Somebody needs to get their hands one of these and end the controversy:

 

I understand. You don't have any proof and you tell everyone to prove that you say is NOT true instead of the other way around. Typical hifi logic

I ask again, hopefully you could at least TRY to answer me. If the vinyl gets as warm as 300 C by the needle, how can it cold down so fast as under 2 seconds? As I said before, tests have been done playing the same groove for hours and hours, and with minimal wear for the best cartridge. If that you said is true, it would not be minimal wear but the groove would be totally ruined. That was not the case.

 

From the test done in Sweden:

"Jag spelar med Ortofon OM40, och har gjort långtids-slitagetester genom att spela ett enda varv upprepade gånger under ett helt dygns tid (vilket motsvarar, tro det eller ej 48 000 spelningar!). Varvet var praktiskt taget helt oanfrätt efter testen.

Samma test med vissa andra pcikuper renderade klart höjd brusnivå och lika klart hörbart skada/avrullad diskant efter bara 2-3 minuter (motsvarar 60 - 100 avspelningar). "

If I would translate it shortly to English it would be that they did a long term test on the wear of different cartridges did to the vinyl. They played a singel groove (specially made) over and over and look at it. Many cartridges did make audible wear after 60-100 plays (higher noise level + wearing to the treble with damage). But with OM-40 they could play for one day (around 48 000 plays), without any big damage at all!

So, if one can play the same groove over and over again, for a day, with minimal wear with the best cartridges, the talk about vinyl getting as warm as 300C from friction of the needle don't sound as likly.

 

I don't really know. I talked to the guy about it and he remember OM-30 and OM-40 (that did the test best), but he didn't remember from memory what other. I could ask him to look it up but this test was done around 15 years ago so most cartridges from then are out of production now. I know he is/was VERY impressed with the Madrigal Carnegie I.



I have more about this "warming up the vinyl":

"One of my favourite websites is TribologyABC.com, source of many useful calculators and much help with the design of bearings. I recently bought the associated book "Advanced Engineering Design" and am steadily ploughing through it.
On reading the section on frictional heating in a ball on surface contact I realised that the same calculation could be brought to bear on the chestnut regarding the heating effect of a diamond stylus on vinyl. The appropriate calculator is 5.5 on the website.

If we use appropriate values for the diamond / vinyl interface, making worst case assumptions where values are hard to determine, we can calculate a temperature rise for contact patch of the vinyl surface. The answer comes out to about 10oC. No, that's not a typo, that's 10 degrees celsius or 18 degrees Fahrenheit.
The 24 hour rule is dead. Don't start with the stuff about slow recovery after deformation, it's called stress creep and the recovery time is proportional to the creep strain which in turn is proportional to the stress duration, so the recovery period is of the same order of magnitude as the stress period.

For those who want to check my results, I used the following values:

Thermal conductivity diamond = 1000 W/mK.

Thermal conductivity PVC = 0.16 W/mK

Thermal diffusivity PVC = 1.2 x 10^-7 m^2/s

H (Hardness of interface) = 1 GPa (the hardness of the softer material dominates)

F = 15 N (1.5 g VTF)

V = 0.5 m/s

mu = 0.4 (a reasonable value for PVC/ diamond)

Assumed radius of contact patch = 70 um (deliberately large as the frictional coefficient of polymer materials increases as the contact pressure decreases, in contrast with classic solid bodies where the two are independent. This is why wide tyres work.)

By the way since we are working with a soft polymer Ar is roughly equal to An and it is easy to throw the calculator out of whack by giving values which would make Ar > An (which is impossible). AFAICS this does not affect the accuracy the model. "

http://db.audioasylum.com/cgi/m.mpl?forum=vinyl&n=589864&highlight=temperature&r=&session=

 

Well, two more, Goldring Electro II, Ortofon SPU was in the test also. But both did wear the vinyl more than the OM-40.