HOME  |  NEWS  |  BLOGS  |  MESSAGES  |  FEATURES  |  VIDEOS  |  WEBINARS  |  INDUSTRIES  |  FOCUS ON FUNDAMENTALS
  |  REGISTER  |  LOGIN  |  HELP
Page 1/2  >  >>
Ann R. Thryft
User Rank
Blogger
Re: Interesting material
Ann R. Thryft   1/31/2012 12:36:16 PM
NO RATINGS

I think some of the confusion has to do with what is considered reuse, and whether we're discussing single-use or multi-use (a confusing term) plastics. Since multi-use is confusing, the SPI and other industry bodies usually use the term "durables". The definition of single use in a plastic, such as a plastic water bottle, is that you drink your water and then either throw it away, whence it goes to the landfill, or recycle it. But the Reduce, Reuse, Recycle mantra suggests we reuse a plastic bottle several times before recycling it. In any case, you don't recycle an item made of single-use plastic until the end of its life as that product, in this case a bottle.

An appliance or a phone is made of durable plastics. You don't throw away either one after using it once, hence the other term, multi-use. But at the end of its life as a phone or an appliance, it can then be recycled, and its material be used in another type of product.


Dave Palmer
User Rank
Platinum
Re: Interesting material
Dave Palmer   1/4/2012 5:48:41 PM
NO RATINGS
@Ann: You seem to be using the words "reuse" and "recycle" in a very unusual way. To me (and, I think, to most people) reusing a plastic bottle would mean washing it out and putting something else in it.  Recycling a plastic bottle would mean grinding it up and remolding it into a new plastic bottle.

By your definition, if I take a plastic bottle, grind it up, and remold it into a new plastic bottle -- which is what most people, whether they are consumers or people in the plastics industry, would call "recycling" -- I'm reusing it, not recycling it.  But if I burn it (waste to fuel), I'm recycling it.

I see your logic, but I don't think your usage agrees at all with the commonly accepted definition.

Your definition would also imply that anything which is flammable is recyclable, which would stretch the definition of "recyclable" considerably for plastics (and would also imply that most metals are not recyclable).

Ann R. Thryft
User Rank
Blogger
Re: Interesting material
Ann R. Thryft   1/4/2012 12:44:27 PM
NO RATINGS

To answer your question, Dave, recycling usually refers to what happens to the material at the end of its useful life, rather than reusing it during its useful life, as in the (implicitly linear) mantra Reduce, Reuse, Recycle. Biodegradation is only one of several recycling possibilities. Others include converting waste to fuel. And pyrolysis is one of several waste-to-energy (WTE) methods for that conversion.


Ann R. Thryft
User Rank
Blogger
Re: Interesting material
Ann R. Thryft   1/3/2012 12:30:52 PM
NO RATINGS

I love the Star Trek references, also. Dave, thanks for the update on that transparent aluminum concept. And I'm with you about Science News--I've received it as a subscriber for several decades, and most of its content is accessible online without charge.


Dave Palmer
User Rank
Platinum
Re: Interesting material
Dave Palmer   1/2/2012 10:17:48 AM
NO RATINGS
@Ann: Fair enough -- this material challenges the generally accepted notions of thermoplastic and thermoset, so I suppose one term is as good (or as bad) as the other.  However, the title "Thermoplastic resin has glass-like qualities" does not do justice to this material, since amorphous thermoplastics (i.e. thermoplastics with glass-like properties!) are extremely common.  In fact, the title of this article would accurately describe most cheap commodity plastics such as polyethylene.  It doesn't communicate what a profound development this is.

You're right that the authors distinguish between grinding up the material and remolding it, and chemically deactivating and reactivating the crosslinks.  But I think the term "recycling" would be applicable to both -- after all, grinding up a polymer and remolding it is how most current plastics recycling is done.

I'd be interested to know what your reading has taught you about the use of pyrolysis in recycling polymers.  From what I know, pyrolysis (thermal degradation in a non-oxidizing atmosphere) produces gas and char.  I have a little experience with pyrolysis as a polymer analysis technique -- basically, identifying a polymer by the "fingerprint" of gases it gives off when it is pyrolyzed.  I have hard that in some cases, the gas can be burned as fuel, and the char -- which is basically just carbon -- might have some potential uses as well.  But neither of these is really recycling, at least in the sense in which most people use the term.

Ann R. Thryft
User Rank
Blogger
Re: Interesting material
Ann R. Thryft   12/27/2011 12:41:05 PM
NO RATINGS

Rob, the material has just been invented in R&D. And Dave is right, this is basic research sponsored by the French government, like the U.S. government used to sponsor. (The link is actually to a lab that is funded by CNRS and ESPCI.)

However, some applications are mentioned in a press release

http://www2.cnrs.fr/en/1932.htm

They include aircraft, electronic circuits, and automobiles. So I suspect this was done with at least some applications in mind. I agree with Dave, I suspect because it's a new class of materials it will be a few years before we see it commercialized. Look how long it's taken for carbon fiber composites!


Ann R. Thryft
User Rank
Blogger
Re: Interesting material
Ann R. Thryft   12/27/2011 12:39:27 PM
NO RATINGS

Dave, thanks for the feedback and clarifications.

Most of the discussions I've read distinguish between a thermoplastic and a thermoset depending on their behavior, not on their structure. Regarding pyrolysis, I've read a lot about its use in recycling for a variety of plastics, not just CFRP composites. And yes, I do understand that it breaks down the polymers. The other two methods you mention, alcoholysis and hydrolysis, make a lot more sense if they can keep polymer chains intact. 

But I think you are merging two different categories. The authors talk about both reusing and recycling. The first is re-shaping the material, which they did indeed do by grinding it up and remolding it. Recycling is described separately as an end-of-life process.


Tim
User Rank
Platinum
Re: Interesting material
Tim   12/25/2011 3:33:16 PM
NO RATINGS
Thanks for the clarification. On re-read, the article does state that the material can be hard or soft.

Rob Spiegel
User Rank
Blogger
Re: Interesting material
Rob Spiegel   12/22/2011 2:36:46 PM
I like the reference to Star Trek, William. A lot of those show, I think particularly Star Trek, focused on what technology might be available in the future. Star Trek really cam out of the tradition of science fiction -- as opposed to fantasy like Star Wars. One of the great aspects of the early science fiction was the emphasis on science.

Dave Palmer
User Rank
Platinum
Re: Interesting material
Dave Palmer   12/22/2011 10:15:12 AM
@Tim: The authors actually discuss two formulations in their article.  One behaves like an elastomer at room temperature, the other behaves like a glass.

@williamlweaver:  I laughed when you mentioned Star Trek IV, but your comment absolutely captures the potential impact of this development.  By the way, while transparent aluminum as a construction material is still science fiction, a couple of years ago a group succeeded in making aluminum transparent for a tiny fraction of a second by using an extremely high powered laser to knock out all of the free electrons. And another group found that sodium can become transparent under very high pressures.  It transforms from a metal into something called an "elemental ionic solid."

@William K.: Science magazine is actually published by the American Association for the Advancement of Science; it's not specifically for plastics industry professionals.  In fact, plastics industry professionals probably comprise a very small portion of its readership (which is why coverage of this development in trade publications like Design News is so important).  It is an academic journal which covers an incredibly wide range of topics.  For some reason I have access to the full text at work.

A magazine which covers a similarly broad range of topics, but on a level accessible to the general reader, is Science News.  Pretty much all of their content is available fre online.

Page 1/2  >  >>


Partner Zone
Latest Analysis
Take a look through these film and TV robots from 1990 through 1994.
The Soofa is an urban smart bench that provides mobile device charging as well as collects environmental information via wireless sensors.
Sciaky, provider of electron-beam additive manufacturing (EBAM) services, will start selling these machines commercially in September. The company has used its EBAM 3D printing technology for making very large, high-value, metal prototypes and production parts for aerospace and defense OEMs.
At this year’s Google I/O, the spotlight was pointed on gender inequality in the high-tech industry. Google has established a new initiative that it hopes will even out the playing field, Made w/Code. Part of this initiative will fund free online courses in basic coding.
Self-driving vehicle technology could grow rapidly over the next two decades, with nearly 95 million “autonomous-capable” cars being sold annually around the world by 2035, a new study predicts.
More:Blogs|News
Design News Webinar Series
7/23/2014 11:00 a.m. California / 2:00 p.m. New York
7/17/2014 11:00 a.m. California / 2:00 p.m. New York
6/25/2014 11:00 a.m. California / 2:00 p.m. New York
5/13/2014 10:00 a.m. California / 1:00 p.m. New York / 6:00 p.m. London
Quick Poll
The Continuing Education Center offers engineers an entirely new way to get the education they need to formulate next-generation solutions.
Aug 4 - 8, Introduction to Linux Device Drivers
SEMESTERS: 1  |  2  |  3  |  4  |  5  |  6


Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.
Next Class: August 12 - 14
Sponsored by igus
Learn More   |   Login   |   Archived Classes
Twitter Feed
Design News Twitter Feed
Like Us on Facebook

Sponsored Content

Technology Marketplace

Copyright © 2014 UBM Canon, A UBM company, All rights reserved. Privacy Policy | Terms of Service