How to Select a Polymer

State your polymer charactristics and expected performance behaviours. Then we shall look for the task.

Hmmm. It seems odd that a good polymer supplier can't help you out on selecting the right material. Unless you're looking for a really freaky spec. Like "must be opaque only to reality TV shows" or something.

Sadly, I can't help you with IDES or material selection. But I can recklessly encourge you to keep right on dreaming! We need more loons out there thinking up crazy new things!

(And btw, if someone out there does know of a polymer that's only opaque to reality TV, please drop me a line.)

Sure. It's called a polarized film, which you turn on and off by an electronic switch.

You can purchase a month of access to the Property Search for $99. The friendly folks at IDES are happy to point you to a material supplier that can help with your project even before you purchase a subscription. Give Ann or Melissa a shout for help, 800-788-4668 x2.

No one can help you if we don't know what you need.

List as many properties as you can. Also, are you concerned about giving away trade secrets?

More info in = better answers out!

I want to thank you all for your responses. Actually being tall and somewhat ungainly, I could be mistaken for a loon late at night. I do enjoy humor of all types. I will contact IDES about the $99 special for one month. That way I can keep this close to the vest for the time being. I have done enough research to know that peek is the best choice thus far except for the price. There are other choices I have found but want to exhaust my research before putting my money where my mouth is, so to speak. I may be back for more information, but for now thank you again.

You have to pay for performance. Volume drives the price.

Good luck.

Hello Lyn,

The two sentences go in the opposite direction! What side is the luck? A message from Gil.

I can relate to that. PEEK was the best choice for a medical disposable device. We gave up because it was 20 times the cost of the metal we were using.

If PEEK is the material that best fits the bill you should also consider PEK (polyether keytone), and PPS (Polyphenolsulfone). You should also look at glass fiber or carbon fiber or carbon black filling for specific property enhancements.

Teflon and Tefzel are other possibilities but they are softer but with a wider temperature and chemical compatibility.

AIP (American Industrial plastics) in Daytona Beach Florida has some nice materials properties charts online.

Hi Michael,

Why you want to pay for informations? You think money will give you the right answer? Money don't buy knowledge. People want your money, that's all! Talk to manufacturers of polymers, they have free knowledge and informations for you. This is a matter of choice, Gil.

www.matweb.com

Hi Michael,

As you stated no one can help you. First, specify what performance is the most important, the second, and if you have another, mention it. Also, did just finish school? Everyone working with suppliers, creates an agreable and knowledge transfering relationship to get the must out of the supplier contact's company. They create polymers for very specific applications and when you contact a few, you almost get what you need.

We are not manufacturers of polymers, so we have hard time to help you. Follow ones recommendations and act accordingly. Remember; Success comes from someone else's head! So, use them, Gil.

Most suppliers will give you recommendations for THEIR material, but it may not be the best value overall. It may help to contact a material compounder, like RTP or LNP. They use all material manufacturers' plastics, then compound colors, glass fibers, mineral fill, Teflon, silicone, etc. to produce specialty compounds. While the final product is always more expensive than the base resin used, it may be ultimately lower in cost for the properties you need. They may be able to produce a compound that starts with a much lower cost base resin, add glass, carbon, or aramid fibers, etc., and end up with a material with the physical properties of a higher cost material. Their recommendations are free. I suggest having them sign a non-disclosure agreement before giving away too many of the secrets of your design.

Hi Zoomer,

I agree that raw material suppliers talk about their products but can solve the problem.

Also, compounder's words can or cannot solve the problem.

All informations come from no guarranteed solution but when you have nothing the info you receive is valueable. How valueable is? This is the receiver's judgment who establish the verity.

So, in conclusion, and this is my suggestion, get info from all kinds of people and judge and choose the best for what you need.

Never forget; Sender know something but receiver understand something too, the same thing or different. This was the Gil's voice.

I have been reading the posts to this site and am gaining confidence in your credibility and honesty. So I have decided to share my project with you. I am designing a new turbine blade that can be made through injection molding. This will not be steam or gas driven but rather through the vaporization of a working fluid(kyoto approved) in a condensing turbine. The heat source is a solar collector heating a fluid that vaporizes my working fluid. So; I need a polymer that is dimensionally stable up to 220c, and has good wear resistance and can handle centrifugal forces in excess of 1800 rpm's. Other qualities would include a surface that would absorb as much of the energy as possible. I read somewhere that polymers with greater drag( my word, the slicker the surface the less drag) might absorb more energy and thus more torque. Chemical resistance is not of great importance as the working fluid is non corrosive. The co-efficient of expansion would need to be low but not to the extreme. I am also looking at using an impulse method of driving the turbine and timing of the impulse jets would be a trick I will have to deal with later. I am also thinking that this would necessitate the use of a flywheel to even out the rotational torque. I hate to be so cautious but I have been burned more than once. But then even a tortoise must stick out his head to get anywhere.

the working fluid may still be an issue due to swelling of the polymer. if the working fluid is water based for instance, PPS would be ideal because it only absorbs about 1-2% of it's weight of water, but it is much weaker than PEEK. Other materials can absorb as much as 20%. (nylons) and most are around 5-10%. If it is oil based, the material may cause the polymer to break down over time. Swelling might not be a big issue if you consider a steady state of absorption and dimension accordingly to allow for the swelling.

you might do better looking at an aluminum metal injection molded part.

Hi Chach,

Who inject what to where here? If I understand, and I am limited up to 0.01% through absorption of lettres and words combined to sentences. From something, eventually interesting or talkable about it, we went to experience personal delivering of a text, which is not related to the subject or very far from it, and I gossip of occurrence of "How to Select a Polymer".

Why we use our brain, fingers, screen space, and lots of time of everyone, including the writer's without "Nobel Prize of Literature" or "Science"? I understand your frustrations about "lack of precisions" in the title but you can ask for explanations and see what's the answer, and follow up accordingly.

Stay serious or step out, Gil.

Dude, you are making absolutely no sense at all. This is the epitome of word salad.

Hi Chach,

From your dude ranch you call everyone "DUDE"? It's fine like the the good or bad comment criticized by someone! What's your problem with your comments? Or, you just like that? Bye-bye, Gil.

NB: I put my name on every comment, and this is education!!!

Yes. Just what are you trying to say?

I am presently considering a hydrofluoroether as my working fluid. Not water. Whether I heat the 'ether directly or via steam is as yet undetermined. Either may work.

Then stay away from any of the PTFE/teflon or teflon derivatives (tefzel) because I suspect they will come apart on you.

Hi Mike,

Your "hydrofluoroether" is a new polymer? Aha, polymerized!? Interesting! The "steam" you want to use is "water", between us, but you said that you don't want to use "water"!? Please, explain, Gil.

Water may or may not be the agent I use to vaporize the hydrofluoroether to drive the turbine. Assuming I use water, the "hot" water would heat the working fluid (HFE) in a heat exchange unit until it vaporizes and that in turn drives the turbine. The hfe would then be captured in the condensing portion of the turbine and reused over and over again.