To determine the actual deformation-force relations, complex groove impedances have been measured as a function of tracking force, groove speed, etc.

At high bearing loads complete plastic flow sets in and the needle leaves a permanent indentation track, while at lower loads the elastic deformation is predominant.

I'm just pointing out that your belief that the practice is harmless is not supported by the facts.

Repeated playback (no matter what the timeframe) carries the risk of permanent damage. Obviously, records are observed to wear out with repeated play. No published evidence exists of back-to-back playback causing any more permanent damage than if repeated plays are separated by any longer period of time.

http://onlinelibrary.wiley.com/doi/10.1002...010508/abstract

Polyvinyl chloride acetate (PVCA) is a thermoplastic copolymer of vinyl chloride and vinyl acetate.[1] It is used in the manufacture of electrical insulation, of protective coverings (including garments), and of credit cards and swipe cards.

. The most common plasticizers are derivatives of phthalic acid. The materials are selected on their compatibility with the polymer, their low volatility, their low toxicity, and their cost.

Copolymers of ethylene and vinyl acetate (E-VA) of a certain composition can be used for the improvement of impact properties (elasticisation) of PVC as well as under certain conditions (grafting) for the preparation of flexible PVC (plasticisation). Products of interesting properties are prepared by blending E-VA (up to ∼ 12%) with PVC or more advantageously by grafting vinyl chloride on special E-VA types. Graft copolymerisation by the suspension method allows the synthesis of E-VA/PVC systems in all ratios (up to 80% E-VA); these polymers are compatible over the whole range in contrast to the blends.

Plasticizers
It has been claimed that some plasticizers leach out of PVC products. However plasticizers do not readily migrate and leach into the environment from flexible vinyl articles because they are physically and tightly bound into the plastic as a result of the heating process used to make PVC particles.

To determine the actual deformation-force relations, complex groove impedances have been measured as a function of tracking force, groove speed, etc.

It would be nice to know from the original paper what they found to be the tracking force where elastic deformation is dominant vs. permanent deformation.

It should also be mentioned that the development of heat during the playback is likely significantly reduced by a cooling agent, be it water alone or in a mix of alcohol (isoprop), thus further reducing the risk of permanent deformation.

I could not find any reference as to what plasticizers are used in PVC specifically for vinyl records. Or that Vinyl acetate was specifically used at all.

... records are a complex chemical mixture including 85% polyvinyl chloride (PVC), 15% polyvinyl acetate (PVA), antistatic agents, dyes, stabilizers (heavy metals such as lead stearate), modifiers and lubricants. PVA, the exact chemistry of which varies among companies, both aids in the flow of vinyl during record pressing and as a plasticizer. Plasticizers play a critical role in softening the plastic/resin.

Plasticizers
It has been claimed that some plasticizers leach out of PVC products. However plasticizers do not readily migrate and leach into the environment from flexible vinyl articles because they are physically and tightly bound into the plastic as a result of the heating process used to make PVC particles.

So again the study by the so called scientists by Discwasher seems to be more than flawed and not worthy any consideration imo.

Most of the heat is produced inside the groove walls by the pressure of the stylus deforming the vinyl, not the friction of the stylus against the walls. The presence of a cooling agent has little effect.

For me, the evidence was that Discwasher found large quantities of acetic acid on the disc surface

including 85% polyvinyl chloride (PVC), 15% polyvinyl acetate (PVA), antistatic agents, dyes, stabilizers (heavy metals such as lead

The plasticiser dissolves the paint and welds the cable and paint surface together, peeling the paint when the cable is moved

I have no experiential references to your statement.  I do not know what you are talking about.
The worst thing that I found regarding plasticizers is the deteriorating foam of old SLR cameras ( I collect pentax slrs, for use, not show) >40 years old.

Quote from: kraut on 2012-04-07 03:56:19

I have no experiential references to your statement.  I do not know what you are talking about.
The worst thing that I found regarding plasticizers is the deteriorating foam of old SLR cameras ( I collect pentax slrs, for use, not show) >40 years old.

IF we are to build knowlege, we must build on what others do that has been tested and verified, stuff like understanding that wet playing is hard on records, and that groves do deform due to accileration alone in vinyl playback.  It is, after all, despite your faux skepticism, nothing but physics.

The same is true for the deformation, elastic or otherwise that depends on the design of the tonearm, cartridge mass, tracking weight etc. If you want to ignore those parametres and how they change the actual wear and tear on a record - why do you even participate?  Just to piss on everybody else who has questions?

... What does it matter where the heat is produced? If the groove wall gets deformed, the resultant heat will still be dissipated faster with a cooling agent present than without. And the cooling agent is in the groove after all. I do not understand your argument.

By your logic water surrounding a combustion motor cylinder will not help dissipate the heat because the heat is produced inside the cylinder?

Evidence by Discwasher is tainted, biased and therefore useless. Show me proper analysis of what is found with proper ph readings and I might be convinced. Other than that - hearsay.

Jean Hiraga, 1978: having read statements concerning tube amps by Hiraga, I have some difficulty accepting him as a serious source.

The plasticiser dissolves the paint and welds the cable and paint surface together, peeling the paint when the cable is moved

I have no experiential references to your statement.  I do not know what you are talking about.

The worst thing that I found regarding plasticizers is the deteriorating foam of old SLR cameras ( I collect pentax slrs, for use, not show) >40 years old.

...I recommend this discussion for those interested in optimal storage of LPs...

Deteriorating foam has had a large effect on the audio scene as well.

Quote from: splice on 2012-04-07 10:26:47

Deteriorating foam has had a large effect on the audio scene as well.

Like in woofer suspensions disintegration which, AFAIK, in the long terms is caused much more by aging than by the mechanical stress of (reasonabily proper) playing.

and, btw, the AES e-library is free to search.  Results are returned with abstracts.

e.g. 'vinyl' gets 293 hits, here's a few I foudn particularly interesting:

Quote

The Limiting Tracking Weight of Gramophone Pickups for Negligible Groove Damage

It has been observed that when spherical styli are dragged over flat vinyl surfaces, scratches are produced under loads considerably exceeding the elastic limit as calculated from theory. The author, in this paper, describes the results of his experiments which bear out his argument that under load the point of yield begins below the surface; and reaches the surface, producing visible tracks, only after the calculated yield load is exceeded. This critical value of load for styli of various radii has been measured and found to be equivalent to, for a 1-mil stylus, 0.64 gm. for a 90° record groove. No size or skin effect was found with the vinyl material tested.

Author: Barlow, D. A.
Affiliation: Aluminium Laboratories, Ltd., Banbury, Oxon., England
JAES Volume 6 Issue 4 pp. 216-219; October 1958

Quote

Groove Deformation and Distortion in Recordings

The elastic and plastic deformation of vinyl record compound under indenters of various profiles has been studied in large-scale tests. Curves of total depth of penetration versus load have been used to calculate the net distortion on record playback. In general, in the lower treble, net distortion is less, and in the upper treble, net distortion is greater than tracing distortion alone. This is important for attempts to reduce tracing distortion by inverse predistortion of the recorded signal. Nylon was also studied as a material with contrasting mechanical properties to vinyl. Further light has been shed on the nature of translation loss.

Authors: Barlow, Donald A.; Garside, Gerald R.
JAES Volume 26 Issue 7/8 pp. 498-510; August 1978

Quote

Comments on "On Stylus Wear and Surface Noise in Phonograph Playback System"
When a set of conclusions is reached in a study as fundamental as this, it is certain that particular factors have been accepted as a part of the working hypothesis essential to the formulation of conclusions which are open to challenge by another student of the subject. Mr. Barlow's studies, like those of Prof. Hunt, are thorough and represent another view of the same subject. Almost invariably, the points of departure in such cases become the focal points for study by all concerned. The process of further investigation usully results in the collection of additional test data that removes the subject from the realm of scientific speculation, and places it within the established body of knowledge of the art. Readers wishing to offer supporting or different viewpoints of their own for publication are invited to address them to the Editor. Such comments are especially welcome.

Author: Barlow, D. A.
JAES Volume 4 Issue 3 pp. 116-119; July 1956

Quote

Determination of Sliding Friction Between Stylus and Record Groove

A method is presented for determining the coefficient of sliding friction between stylus and record groove. The method consists of measuring the time intervals required for a freely rotating record (on a turntable) to decelerate from one known speed to another, both with and without a stylus sliding in the record groove. The method as been used to evaluate the frictional characteristics of several brands of phonograph records in mind condition and after treatment with various preservatives, cleaners, and antistatic agents. Some test results are presented
Author: Pardee, Robert P.
Affiliation: Ball Corporation, Aerospace Systems Division, Boulder, CO
JAES Volume 29 Issue 12 pp. 890-894; December 1981

.

Quote

Disc Record Care and Cleaning Accessories

Since the paper presented by me on a similar theme to the 50th AES Convention at the Cunard International Hotel in London in 1975, investigations into developments in this area have been pursued vigorously both in the UK and in other countries to tackle the problems of -record cleaning- and maintenance.

Author: Aldous, Donald
Affiliation: Hi Fi News and Record Interview, Plymouth
AES Convention:65 (February 1980)

Quote

An Investigation into the Increase of Non-Linear Distortion Products from Virgin Tape to Disc Playback

A study was carried out in order to examine the increase in distortion products arising from the various stages in the recording process from virgin tape, via tape copies, right up to and including interaction with specific record pick-up distortions. 1 kHz sinusoidal signals as well as some IM (400 + 4000 Hz) and double tone (9800 + 10200 Hz) signals were recorded at levels increasing in discrete 3 dB steps starting in non-critical range and continuing up to tape compression level. The tape -original- and first and second generation copies were then transcribed together onto 12" LPs. This made possible a study of the distortion progression and also the second and third order distortion combination products. The current practice of recording right up to the modulation limits of the tapes as well as of the disc seems to result in a total distortion percentage which considerably degrades the sound quality. In order to gain an impression of the audible effect of these distortions, some special musical samples were recorded with the same discrete level steps as the measuring signals. These musical samples were subjected to the same copying and transcription processes as the measuring signals and were similar in character (single tone, multi tone). Listening to these musical sample records provided an opportunity to establish perceptibility limits for the human ear regarding amounts of disturbing distortion.

Authors: Stephani, Otfried; Blüthgen, Björn
Affiliation: Polygram GmbH, Hanover, Germany
AES Convention:62 (March 1979) Paper Number:1453

Quote

An Experimental Study of Groove Deformation in Phonograph Records

Groove deformation has been analyzed in the literature primarily in terms of classical elasticity theory, which is based on assumptions that are not appropriate for stylus-groove contact. To determine the actual deformation-force relations, complex groove impedances have been measured as a function of tracking force, groove speed, etc. The results obtained are contrasted with classical predictions.

Author: White, James V.
Affiliation: Acoustics Research Laboratory, Harvard University, Cambridge, MA
JAES Volume 18 Issue 5 pp. 497-506; October 1970

Quote

Factors Affecting the Needle/Groove Relationship in Phonograph Playback Systems

It is shown that a phonograph pickup stylus riding in the groove of a record partly penetrates the groove walls because of elastic and plastic deformation of the record material. At high bearing loads complete plastic flow sets in and the needle leaves a permanent indentation track, while at lower loads the elastic deformation is predominant. This leads to amplitude distortion in the reproduced signal which may be of two types: one which is a function of the recorded wavelength (G function or translation loss), the other a function of the dynamic moving mass of the stylus/armature (H function or stylus/groove resonance). A third phenomenon (S function or scanning loss) is caused by the finite size of the stylus/groove-wall contact surface. Experiments with specially built pickups show the evolved theory to be valid even for very high frequencies. Special test records with recorded frequencies up to 100,000 Hz were used for these experiments.

Author: Bastiaans, C. R.
Affiliation: Westinghouse Research Laboratories, Pittsburgh, PA
JAES Volume 15 Issue 4 pp. 389-399; October 1967

It appears to me that if Kraut just bothered to read the abstracts, he's sing a different tune!

It appears to me that if Kraut just bothered to read the abstracts, he's sing a different tune!

@splice: That's an awful lot of conjecture, and frankly I see almost nothing that I would agree with.

We were indeed making great strides in vinyl technology in the 80s, and the Soundstream system was real. The remaining candidates for conjecture are my musings on sample depth and rate, and the possible physical carrier form. I look forward to hearing your reasons for disagreement. You can PM me if you prefer, and if it has legs we can open a thread for it.

@-h, I happen to agree with almost everything you wrote. Where I beg to differ is in the "striving for exotic systems". I believe we should strive, but not because it raises the price. Some people have the disposable income to indulge their desires to own exotic systems. Their investment pays for the R&D that eventually filters down to "affordable" systems.

I'd like to see more attention on the capture and rendering of spatially realistic audio and reference playback behaviour (absolute loudness, frequency response etc).

-k

Having no access to the info, I am asked to accept vague abstracts as proof of what?