PTFE - Acceptable synthetic?

Forum for the discussion of any material/synthetics.Only posts with info /or links to research info allowed . Any posts recommend the use of any material without copy's or links to show proven research will be deleted

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Mud
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PTFE - Acceptable synthetic?

Post by Mud »

This is a question for the mods. In another thread
theholymackerel wrote:...A material data sheet that shows how the material resists ethanol isn't a good link... we need to know what the material does to the ethanol, not the other way around. A link to new plastic technology that explains how a carbon barrier seperates the plastic from the ethanol is GREAT info. A chemist in the alcohol industry explainin' that PTFE tape is a special situation and safe, is GREAT info....
Mud wrote:Can we take this as an endorsement for PTFE, Holy? The mods don't seem to have much to say about PTFE, anyway. Is this the exception in synthetics?


-Mud
Considering The Chemist's position, and his credentials I now use PTFE on all threaded connections in my still and as gasket material. Lots of other distillers do, too, but quietly, in order to avoid getting whipped over using "plastic". Can we have an answer as to whether it is acceptable to openly discuss the use of PTFE?

-Mud
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Re: PTFE - Acceptable synthetic?

Post by minime »

Mud wrote:The Chemist's thread concerning PTFE is: here
Considering The Chemist's position, and his credentials I now use PTFE on all threaded connections in my still and as gasket material. Lots of other distillers do, too, but quietly, in order to avoid getting whipped over using "plastic". Can we have an answer as to whether it is acceptable to openly discuss the use of PTFE?
-Mud
Me too, been using Cole Parmer's compatibility widget http://www.coleparmer.com/techinfo/ChemComp.asp" onclick="window.open(this.href);return false;" rel="nofollow for verification.
After watching many episodes of the thirsty traveler and seeing hoses used in direct production in commercial distilleries I started investigating and found there is FDA approved specially treated silicone tubing for ethanol production. It is Platinum cured probably the same process used on Carbon coated plastic bottles. Extremely expensive stuff though so not likely something for the hobbyist. Example from Cole Parmer is almost $3200 Canadian for 50 ft :!:

EW-95703-06
Reinforced silicone (platinum-cured) tubing, 1"ID x 1-3/8"OD, 50 ft/pack (package)
Price (CND) $3178.16 / package
Certifications FDA, USP, NSF, GMP
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Re: PTFE - Acceptable synthetic?

Post by Ugly »

I alluded to this high price range earlier, you'll also find Iridium cured silicone products in this price range (per sq/cm ballpark) available in sheets or stamped gaskets as well as O-rings and spaghetti seals . Depending on the application it's sometimes cheaper to make a gold or silver plated copper gasket so if it doesn't have to come on and off once a day there are other ways.

Most big commercial systems are engineered to utilize metal on metal connections wherever possible. That's the key lesson.
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Re: PTFE - Acceptable synthetic?

Post by Tater »

Maybe we can get the chemist to elaborate on his tests of PTFE what brand he tested and such.As has been stated all along on this forum reason we are anti plastic .Is lack of reliable info as to what ends up in the final product . Even with that post you quoted some have not had good results using PTFE.Example for this is a post from another forum-------------------------------------------------------------------------------------------------------- PTFE/Teflon and ethanol solubility
PostPosted: Mon Feb 16, 2009 4:24 am




I've used it on my column to keg threads since the second run and I've broken it down after some issues in the middle of a run and the tape was perfectly fine. The rest of the times have been a full run down mostly to 20% or so and it discolors a bit and gets a tad brittle and crumbles off on disassembly. ---------------------------------------------------------------So what ya reckin caused this ?Different brand of tape? Maybe its now being made in china I don't know.To many variables for me to trust it .You use what ever ya want.I for 1 however would like to see lots more information of its use in our field .Flour paste works its safe Ill stick to it.However reliable information on a material is always welcome.
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Re: PTFE - Acceptable synthetic?

Post by HookLine »

This chart says PTFE is resistant to ethanol up to 100 ºC. (The reason I put it up is that most charts only give resistance up to 50C, but we need up to 100C.)

On the same site they also say:

Chemically inert
Fluoropolymer resins [such as PTFE] are essentially chemically inert. This has long been one of the greatest assets of these high-tech plastics. Fluoropolymers and our other engineered polymers are ideal as transport for today's highly volatile chemical compounds and exotic fluids.

The widespread acceptance within the Chemical, Environmental, Aerospace, and Medical industries is a testament to our polymers' unique abilities to withstand and resist a wide variety of liquid and gaseous compounds.

Exceptions
There are very few chemicals, such as molten alkali metals, turbulent liquid or gaseous fluorine, chlorine trifluoride, or oxygen difluoride, that are known to react with fluoropolymers.



And these guys say:

Because of its unparalleled chemical resistance and extreme chemical inertness, PTFE has become a choice plastic for the chemical and analytical sciences industries.
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Re: PTFE - Acceptable synthetic?

Post by HookLine »

This stuff looks interesting.

PEEK
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Re: PTFE - Acceptable synthetic?

Post by Ugly »

Nothing is technically 100% safe or error free. Flour sounds great until we get a flour recall because of excess toxins.. It does happen. Here's a recent link
http://www.nowpublic.com/health/canadas ... can-sicken" onclick="window.open(this.href);return false;" rel="nofollow
There are other links and other contaminates. I just chose one close to home for me.

You don't need an endorsement from anyone to choose your materials. Make up your own mind and do whatever you research as safe. Unsafe choices will result in fewer people, Darwin at work. I get sick of government passing laws in the name of safety and then letting oh... things like bridges collapse. I don't trust anyone but me to make the final decision on what's safe and what's not. I think everyone should take the same approach to personal responsibility and I'm not going to lecture others just because I (for example) feel cork can suck up botulism and poisonous metallic salts like a paper towel when those things would normally be rinsed away from a metal surface.

The only question should be what to say to others. All you can really say at this point is that copper, silver, gold and stainless steal probably won't kill you unless it's contaminated with something and that all other materials are open to personal research. I already know those metals add to the concentrated alcohol, I'm just OK with what they add. I'm also personally OK with the platinum/iridium silicone gaskets I have from my days at the distillery but I don't recommend it to anyone. No one but me has to drink my crap and I'm pretty confident that anyone who shares one with me is more likely to die from me tripping and falling on them.

This recent post (taken out of context) here gives good advice that applies well to all facets of living or trying to stay alive.
goose eye wrote: best advice ole boys can give is - walk in with your eyes wide open an act acordinly -
so im tole
Thats likely the best piece of advice on the whole website.

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Re: PTFE - Acceptable synthetic?

Post by HookLine »

This is interesting.

http://www.tricanada.com/pdfs/rubberfab ... lGuide.pdf" onclick="window.open(this.href);return false;" rel="nofollow
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Re: PTFE - Acceptable synthetic?

Post by Fourway »

This is the same old argument.

synthetic being resistant to etoh is not the same as the etoh ending up with no plastic in it.

NOT THE SAME.

The thread mud dug up was started by a troll.
It was a thread I locked in 2006.

This is THE SAME DISCUSSION.
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Re: PTFE - Acceptable synthetic?

Post by zymos »

Wait, so when The Chemist said he once ran some samples through GC and found plasticizers, that is now the gospel of the anti-plastic faith, yet when he says that PTFE is safe, people get all worried and have to qualify it with disclaimers?
So you are saying trust him when he comes on one side of an issue, but not when he is on the other side?
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Re: PTFE - Acceptable synthetic?

Post by manu de hanoi »

Fourway wrote:This is the same old argument.

synthetic being resistant to etoh is not the same as the etoh ending up with no plastic in it.

NOT THE SAME.

The thread mud dug up was started by a troll.
It was a thread I locked in 2006.

This is THE SAME DISCUSSION.
Saying that PTFE is inert (that's more than resistant) and that it doesnt affect ethanol could only be different in the case where your PTFE contains more that PTFE (for example some remaining solvents) or in the unlikely case it has some catalytic activity.
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Re: PTFE - Acceptable synthetic?

Post by Centimeter »

I was just going to say that I was going to do some GC/MS studies to settle this once and for all. If Chemist did this, then this is settled. I work in a mass spec lab and I can say without a doubt in my mind, as a professional, if GC/MS came up with nothing, there’s nothing to worry about. Period. There is quite literally no more quantitative a test that can be done. Period. If anything was coming out that the GC/MS wasn’t finding, it’s several orders of magnitude too little to even give you a rash. Period.

The studies of PTFE’s resistance to ethanol were most likely conducted using GC/MS to study if the ethanol picked up anything. So, in other words, if PTFE is inert to ethanol than likewise ethanol is inert to PTFE.

I’ll have to look at how The Chemist did his study. If done properly, which I am sure it was, there is really no equivocation. One might be able to get a couple orders of magnitude more definitive with LC/MS, but that’s just splitting hairs.

Just for reference. We got a mass spec (albeit LC/MS) that can pick things up in the picomolar range. That’s 1/1000000000000 moles/L.

Furthermore, the only bad thing that I can see coming out of PTFE would be HF, and that seems rather unlikely. Granted, HF is extremely bad for you. However there has to be a good amount. It doesn’t have a cumulative impact (that I’m aware of). Were it to be produced, which honestly is just about impossible given the circumstances, it would probably either gasify or react immediately with either the copper in the stil or the glass of your collection flask. In both cases, evolving relatively innocuous compounds.

You wouldn’t by chance be able to point me to Chemist’s study would you?
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Re: PTFE - Acceptable synthetic?

Post by Mud »

I don't know that The Chemist ever documented his method. Searching hasn't turned up anything, but that could be me. It sounds like you have the ability to analyze a sample? If so, would you be willing to do it and document it, Centimeter? Yesterday I looked into sending a sample to the lab at a local college. They won't take samples from the community. Something about the potential for illegal substances. :D

A documented study and lab analysis is what we need. This is something that should be resolved considering the interest in VM stills. They require a valve of some sort with synthetic seats, so everyone building one needs to select a proper material.

-Mud

-edited typo
Last edited by Mud on Tue Feb 24, 2009 1:18 pm, edited 1 time in total.
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Re: PTFE - Acceptable synthetic?

Post by Husker »

From my understanding, Chemist has not been able to publish many of his studies, or even tell people the results and I think he has done his work under contract for industry players, and is under NDA, so has no ability to discuss them, let alone publish. I have tried to obtain some info about fast aging, and he has to politely refuse them.

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Re: PTFE - Acceptable synthetic?

Post by Ugly »

Run the sample and publish the results in a professional manner. Use standard methodology, all results should be repeatable given the same equipment and sample. There are private studies you can order for a cost, you just can't republish them after review. Husker's post is correct, we didn't publish lab results either, too much data for a new competitor to just TAKE.
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Re: PTFE - Acceptable synthetic?

Post by Husker »

Yup, those who pay, make the rules. Why would a company pay, and then allow everyone else to have the information for free? A few companies DO work in this way (things like open source software), but by and large, most will NOT allow release of any paid and/or proprietary information.

This is one of the reasons why HomeDistiller has taken such a strong view of any and ALL plastics in the distillation process. There simply is no (or not enough) true VALID publicly available information. Lots of rumors and unwise speculation, but no good hard FACTS. If people DO have access to these types of testing equip, can run some careful and reproducible studies, AND be able to publish them, then we start getting some hard facts in line.

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Re: PTFE - Acceptable synthetic?

Post by HookLine »

Centimeter wrote:I was just going to say that I was going to do some GC/MS studies to settle this once and for all. If Chemist did this, then this is settled. I work in a mass spec lab and I can say without a doubt in my mind, as a professional, if GC/MS came up with nothing, there’s nothing to worry about. Period. There is quite literally no more quantitative a test that can be done. Period. If anything was coming out that the GC/MS wasn’t finding, it’s several orders of magnitude too little to even give you a rash. Period.
Please do. Settle this thing permanently. (Make sure you do proper controls so there is no doubt.)

Also, when The Chemist said that all the alcohol he tested that had been stored in plastic containers was contaminated by plastisizers, he did not say if that included PTFE containers. But it is unlikely that it did, as they would not be used for storing commercial beverage alcohol due to sheer cost alone. Furthermore, given that he also followed up that comment with the qualification that he does not regard small amounts of PTFE (as seals) as a problem, I think we can safely assume that he was not talking about PTFE in relation to this plastisizers issue.
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Re: PTFE - Acceptable synthetic?

Post by evilpsych »

someone with access to a GC/MS could do the following experiment with these test groups utilizing a known quantity of alcohol (say.. Everclear)

1. Everclear
2. everclear in a mason jar (i chose a mason jar because it's very common to distilling)
3. everclear in a mason jar full of ptfe washers (just for overkill)
4. everclear in a mason jar with an unwound roll of ptfe tape
5. everclear in a jar with a valve seat
6. ad nauseum

Step 1. Put jars in a pressure cooker
Step 2. bring pressure cooker up to north of 212F for an hour - simulating higher than normal temps for a still
Step 3. test the samples
step 4. post the results

I imagine we'll get some interesting results off a standard canning lid, that should be easily extractable from the later samples.

I'm also interested in seeing just how much residual copper, silver, iron, chromium and tin are in a sample too. Heavy metals can be just as bad for you in overdoses - and they're DEFINITELY not INERT substances.

For some, no testing will ever be 'conclusive' about ptfe. Just leave them to the 'old-school'. I would posit that most have ingested more PTFE than they realize with no ill effects. Certainly have ingested Bisphenol-A (BPA) in large quantities if you've been alive the last few decades or more.. PTFE is regularly used in the body for parts replacement - even in wear situations - (hips, joints, flexible pieces) without a bit of problem. Inert.
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Re: PTFE - Acceptable synthetic?

Post by zymos »

If someone were to run these, why stop with PTFE? It would be nice to get some data for HDPE and other common plastics, which ARE used commercially to store and ship EtOH.
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Re: PTFE - Acceptable synthetic?

Post by Hawke »

zymos wrote:If someone were to run these, why stop with PTFE? It would be nice to get some data for HDPE and other common plastics, which ARE used commercially to store and ship EtOH.
HDPE spirit bottles have a carbon barier to keep the alcohol from coming into contact with the actual plastic. Non barier bottles would quickly degrade both the spirit and the container.
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Re: PTFE - Acceptable synthetic?

Post by Husker »

I think most spirit bottles (i.e. the cheapo crap sold in 1.75L plastic), are PET, not HPDE. I know little if these are also lined with some form of barrier. There are some 'bulk' HDPE containers which finished 80 proof spirit is shipped in (blue barrels, if memory servers me). Again, these might be (likely) lined.

Also lined, are most AL cans. They have a lined barrier coating, to keep the ethanol (or soda, or whatever), away from the raw AL metal. I actually think Cokacola would be much more destructive to raw AL than beer. I have seen just what Coke does to raw meat, or when used as a minor rust dissolving solution, for things like shining up car bumpers.

If someone IS PLANNING on doing some testing, then there might be different test requirements (heat and pressure, vs long time), for plastics that would possibly be used in any form in distillation apparatus, and plastics that would be used for long term storage. Distillation apparatus would need heat, a little pressure, ethanol VAPOR, and other factors added to the test. Also, a long time frame contact test is not really required (possibly 24 hours), however, performing multiple tests on the SAME material would be, due to likely usage in the real world environment would be to use for multiple runs. For storage, you would mostly need to test a single LONG TERM contact, without the heat/vapor/pressure. For this test, some agitation should be done daily, and daily or weekly tests of the ethanol should done, but the larger solution should continue in the test, for at least a year.

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Re: PTFE - Acceptable synthetic?

Post by minime »

Holy crap Centimeter, you up for all this. Snuffy's been working full time and looks like you've now got a full time position too. :lol:
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Re: PTFE - Acceptable synthetic?

Post by zymos »

Hawke wrote: Non barier bottles would quickly degrade both the spirit and the container.
Sorry, but no.
I've been buying 190 proof EtOH in 5 gal. HDPE cubitainers for well over a decade. They are they same old ones that are used for bulk vegetable oils and many other food products, and their use predates any type of barrier technology by years.

I'm looking at one right now that has a couple of gallons in it, and it has been sitting there for over a year, and, whatever you may worry that it has done to the spirit, the plastic itself has had no damage whatsoever. Every large distillery I've ever dealt with (3 or 4) that sells bulk alcohol uses these containers for 5 gal. lots. That doesn't prove that it is safe, I realize, but the alcohol definitely has no noticeable effect on the plastic. I have some cubes that are several years old that we occasionally fill up with water for camping trips, and they are holding up just fine, even though they once contained 190 proof for several months.
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Re: PTFE - Acceptable synthetic?

Post by The Chemist »

The comments I've made on this subject before have been purely anecdotal. I don't spend my time looking for plasticizers, but do occasionally run across them. But, it's kinda slow around here today, I'm kinda bored...

So...I took about 3 grams of PTFE sheet, cut it into smallish pieces and put it into 50 ml of 95% EtOH, and set it up to reflux. Then I shoved a thin strip of the same material down the condenser, past the "teeth", all the way into to liquid, so that a portion would constantly be bathed in the vapor. Then I refluxed it for an hour, and shot it onto the GC/MS. Nothing. Nada. Zip. There was also no apparent softening of the material in the strip that ran from atmosphere to liquid, even while still warm.

Now. There could be something hiding under the solvent peak, but I seriously doubt it. So, although I do not recommend ANYTHING, I wouldn't be afraid to use PTFE gasket material if I were distilling booze. I would avoid any other plastic like the plague.
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Re: PTFE - Acceptable synthetic?

Post by Tater »

All I wonder about now is all ptfe is made to same standards by all suppliers by some law ? Tks for your input chemist
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Re: PTFE - Acceptable synthetic?

Post by theholymackerel »

Thanks, Chemist.

Well, there we have it:
The Chemist wrote:I wouldn't be afraid to use PTFE gasket material if I were distilling booze. I would avoid any other plastic like the plague.
So use PTFE tape to seal if ya want, but don't use, or encourage folks to use ANY plastic.
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Re: PTFE - Acceptable synthetic?

Post by Mud »

Thanks Chemist. Your input is very much appreciated.

Mods, can we have a modification to Rule #8 stating that virgin PTFE is not considered a plastic, and is accepted on this forum? Just for clarity?

-Mud

edit - posted at the same time as the Chemist. Not trying to jump the gun.
Last edited by Mud on Tue Feb 24, 2009 11:28 am, edited 1 time in total.
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Re: PTFE - Acceptable synthetic?

Post by The Chemist »

Not so fast, there, Mac(kerel)...tape is much more pliable than the material I used, which may be an indication of plasticizers. I may do that experiment if convenient, but the safety of tape is not indicated by this one.

As for whether these results are general to all product, that also is unknown. Product formulations are usually proprietary.
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Re: PTFE - Acceptable synthetic?

Post by Hawke »

Zymos, I did mis-speak, I meant the PET spirit bottles. I do have an HDPE drum for a fermenter, but just don't trust it for high-proof spirits. Maybe Chemist could do a test similar to the one he just did on the PTFE. I think heat and vapor would have an adverse effect.
I have a racking cane made from PET, has never seen more than 12% wash or more than hot tap water. The thing is severely crazed (fine checkering cracks) after use and cleaning on maybe a dozen washes.
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Re: PTFE - Acceptable synthetic?

Post by theholymackerel »

Thanks, Chemist.




OK, Folks: The jury is still out on PTFE tape. Plastics of all sorts are frowned upon, and they are not to be suggested to folks to use.

As always, if anyone finds any info on,or does an experiment about the effects of materials on ethanol/water solutions, please do post the results/info here for further discussion.
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