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Composites In An Accident?  
User currently offlineRuscoe From Australia, joined Aug 1999, 1605 posts, RR: 2
Posted (9 years 10 months 2 weeks 1 day 2 hours ago) and read 4937 times:

Can anyone who knows about composites tell me how they would expect the composite to behave in a serious accident as compared with aluminium.

For instance will it ignite and burn earlier than Al?

Will the craft stay more intact as a structure because it is constructed of several large pieces of structure rather than put to-gether from many more smaller pieces of Al.


Ruscoe

24 replies: All unread, jump to last
 
User currently offlineAUAE From United States of America, joined Apr 2004, 296 posts, RR: 3
Reply 1, posted (9 years 10 months 2 weeks 1 day 2 hours ago) and read 4905 times:

Aircraft already have large composite structures, and they don't seem to withstahd crash forces any better than aluminum. In minor accidents, maybe you could have a good discussion. But for serious accidents, nothing can withstand the amount energy that is released when you bring a body moving that fast and that heavy to a screaching holt.

Shawn



Air transport is just a glorified bus operation. -Michael O'Leary, Ryanair's chief executive
User currently offlineViveLeYHZ From Canada, joined Dec 2004, 194 posts, RR: 9
Reply 2, posted (9 years 10 months 2 weeks 20 hours ago) and read 4818 times:

Ruscoe,

Regarding fire resistance of Aluminum (melting point near 650 C), and Composites (which do not melt per-se, but rather become very soft at the so-called Glass-Transition-Temperature of around 150 C) are BOTH inadequate in the case of a major fire. However, there are fire retardant additives and paints that can give Composites satisfactory fire ratings. I remember the British Navy had a problem with fires on their aluminum frigates during the Falkland's war.

By comparison, the melting temperature of steel is around 1300 C, and still steel structural members must be sprayed with fire retardant to allow occupants time to escape in the event of a fire. Even then, as in the case of WTC in NY, there fire retardant can only last so long, and eventually the fire weakens the steel members causing them to become soft and fail.

The question about the plane being intact after an accident is misleading. It all depends on the strength of the joints connecting the various parts of the structure. Joining composite members is no easy task (in fact, this the topic of my PhD thesis), while aluminum members are weldable, and the ductility of aluminum allows for efficient bolted connectins.

Composites are very brittle materials, therefore bolted connections between composite members are at best 40% efficient (you automatically lose 60% of the member's strength when you put holes in it), adhesive joints on the other hand are very efficient (over 80%).

Nothing is perfect, these adhesive joints are not easy to inspect (unlike fastened joints), this is why many designers do not feel very comfortable with adhesive joints, especially for structural members subject to cyclic loading (interestingly, aircraft frames are the classic example of structures subject cyclic loads)

One final point. Composites give designer the ability to taylor design the elastic properties (strength and stiffness) and orientation of each layer of composite, resulting in very efficient light-weight members. You can't do that with aluminum, the strength and stiffness are the same in all directions.

I hope this answers your question, some what.

Cheers,
ViveLeYHZ


User currently offlineRuscoe From Australia, joined Aug 1999, 1605 posts, RR: 2
Reply 3, posted (9 years 10 months 2 weeks 18 hours ago) and read 4757 times:

Thankyou for that very interesting information.
I read somewhere that Boeing are going to hold their composite fuselage sections to-gether with a titanium strap. Have you heard anything about this?

Thanks,

John


User currently offlineViveLeYHZ From Canada, joined Dec 2004, 194 posts, RR: 9
Reply 4, posted (9 years 10 months 2 weeks 16 hours ago) and read 4718 times:

I haven't heard anything about Boeing's 787 other than it will have more composite sections than any other airliner. I will search the net and Boeing's website today to find out more. Again, this is very much the topic of my PhD thesis, it is what I have been doing day in and day out for the last two years.

Boeing has been building many fighter jets, the area of cutting edge composite technology. Fighter jets have large parts of their main structure made of carbon fiber composites, far stronger than steel, sometimes stiffer than steel, and a whole lot lighter. It is about time this technology gets used in Boeing's civil aircrafts.

As for joining composites, the Godfather of the subject has to be John L. Hart-Smith, who worked at McDonnell Douglas (now Boeing), he even did a lot of contract work for NASA in the 1970's on the subject. If anyone on the planet has the know-how of joining composites, it has to Boeing.

Cheers,
ViveLeYHZ


User currently offline2H4 From United States of America, joined Oct 2004, 8956 posts, RR: 60
Reply 5, posted (9 years 10 months 2 weeks 16 hours ago) and read 4708 times:
AIRLINERS.NET CREW
DATABASE EDITOR

Composites are very brittle materials



Saying composites are brittle is like saying paints are green. It all depends on what's inside.


2H4



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User currently offlineLMP737 From , joined Dec 1969, posts, RR:
Reply 6, posted (9 years 10 months 2 weeks 16 hours ago) and read 4695 times:

In 1994 the Beech Starship taking off from Roskilde, Denmark ecountered icing condition on takeoff. After rotating at 100 knots the pilot noted that the aircraft would not climb. Even when the pilot pulled harder on the yoke the aircraft would still not climb. At this point the Starship settled on the runway at which point the pilot applied full braking and reverse power. However the plane went off the end of the runway and the gear collapsed. Number of fatalities:0. Number of injuries:0. In fact the fuselage was still in one piece. Not bad for a composite fuselage.


User currently offlineViveLeYHZ From Canada, joined Dec 2004, 194 posts, RR: 9
Reply 7, posted (9 years 10 months 2 weeks 12 hours ago) and read 4625 times:

2H4,

Saying composites are brittle is like saying paints are green. It all depends on what's inside.

While I do not mean to sound stubborn, I feel compelled to voice my disagreement with your comment. Here is an brief explanation of why composites are very brittle.

Composites are made of strong and stiff fibers embedded in a weaker and softer matrix. The most common fibers are carbon/graphite (aerospace applications, expensive, excellent strength/stiffness properties) and fiberglass (marine and other applications, inexpensive). These fibers are brittle because their behaviour is linear and elastic upto their failure point.

Since the fibers are load carrying part of the composite (they carry over 99% of the load in the fiber direction), their brittleness makes the composite brittle, no matter how ductile the matrix. Some matrix resins (called thermoplastics) are ductile, however they are rarely used in structural applications due to inferior properties, especially under sustained loading or under moderately-high temperature conditions.

Other materials used in structural applications (namely steel) exhibit what is called YIELDING, where the material exhibits excessive deformation at the yield point with little increase in the load. This deformation is upwards of 10%-20% of the members original length. Clearly, when a material like steel or aluminum yields (approaches failure), excessive deformation is noticed, and in the case of buildings, occupants have a chance of evacuating before total failure of the structure. This does not happen in composites, since they do not exhibit yielding, with no excessive deformation (a sign of imminent failure) the failure tends to be catastrophic.

There are ways of alleviating this brittleness (some what), by providing fibers in more than one direction, none the less, even the most carefully design composite laminates come no where close to the ductility of steel.

One type of composite materials is made by embedding strong fibers in ceramics, which too are very brittle, but their superior strength gives them an advantages over metals, especially for very-high temperature applications (over 2500 F). Example is the space shuttle thermal insulation is made of ceramics.

If there is anything here you do not agree with, I would be happy hear your point of view.

MY $0.02  Smile

Cheers,
ViveLeYHZ


User currently offline2H4 From United States of America, joined Oct 2004, 8956 posts, RR: 60
Reply 8, posted (9 years 10 months 2 weeks 9 hours ago) and read 4576 times:
AIRLINERS.NET CREW
DATABASE EDITOR

Great information, ViveLeYHZ. Thanks for shedding some light on things.

The information you presented seems very accurate and well thought-out, but my original point...that composites can display any number of characteristics...still stands.

Although you contend that composites are very brittle, you then go on to point out that "some matrix resins (called thermoplastics) are ductile".

This is what I'm getting at.

A material (such as a thermoplastic composite) may not be ideal for an aerospace application, but that doesn't change the fact that it's a composite. The characteristics of the composite depend entirely on what materials/resins/prepregs/etc are used.

I've had experience with carbon fiber prepreg structural failure, and came away impressed with just how flexible and resilient the material could be. In fact, if you load a particular carbon fiber tube until it fails, and then do the same with an aluminum tube of equal weight, the aluminum tube will almost certainly fold over (fail) more suddenly and with less warning. Think crushed beer can. The carbon fiber tube (at least the kind I've had experience with) will flex noticably before failure. When failure occurs, it will reluctantly splinter and fold over, similar to breaking a young sapling in half. Breaking it into two seperate pieces is very difficult, and, like the sapling, will likely require lots of bending back and forth before seperation occurs. In other words, this particular carbon fiber does not exhibit any brittle or catastrophic characteristics upon failure. Other carbon fiber blends snap like a twig.

In the end, you can't generalize composites any more than you can generalize metals. For example, not all metals are ductile...I've seen aluminum and titanium components shatter, failing very suddenly and unpredictably. Again, it all depends on what's inside (in this case, grain structure).

I think your information is top-notch, and I'm glad you're taking the time to offer your perspective, but I think you're focusing on specific materials, and then applying their characteristics to everything that falls under a broad term.

Anyway, thanks for a refreshingly thought-provoking post.

 Big thumbs up


2H4



P.S. - Have you had any experience with nanotubes? THAT is some amazing technology...



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User currently offlineRuscoe From Australia, joined Aug 1999, 1605 posts, RR: 2
Reply 9, posted (9 years 10 months 2 weeks 7 hours ago) and read 4544 times:

2H4,
The only thing I have heard about nanotubes is that they have the potential to make composites even lighter.

Can you enlighten me further.

Ruscoe


User currently offlineViveLeYHZ From Canada, joined Dec 2004, 194 posts, RR: 9
Reply 10, posted (9 years 10 months 1 week 6 days 22 hours ago) and read 4476 times:

2H4,

Point taken.

In the end, you can't generalize composites any more than you can generalize metals.

True enough. Thank YOU for the lovely discussion, by far the best I've had on this website.

Ruscoe,

It is funny that you mention nanotubes, they have unbelievably high strength and stiffness. I am trying to use nanotubes in my reserach to improve the load transfer capacity and toughness of adhesive joints. However, I think 2H4 was referring to large size (actual) carbon tubes, on a size scale comparable to a beer can.

Cheers,
ViveLeYHZ


User currently offlineN79969 From , joined Dec 1969, posts, RR:
Reply 11, posted (9 years 10 months 1 week 6 days 22 hours ago) and read 4457 times:

ViveLeYHZ,

I am not intelligent or well-informed enough about materials science to disagree with you. But I do have a question. Have engineers figured out away to make composite fatigue apparent?

For example as you know, companies add a sulfurous smell to naturally odorless methane so people can recognize a gas leak without any kind of special equipment. Is there anything similar for composites in the pipeline?

Thanks.


User currently offline2H4 From United States of America, joined Oct 2004, 8956 posts, RR: 60
Reply 12, posted (9 years 10 months 1 week 6 days 22 hours ago) and read 4441 times:
AIRLINERS.NET CREW
DATABASE EDITOR

Ruscoe and Vive,

I was actually referring to nanotubes on a molecular level. Incredible stuff. I don't have time to post quality info about it right now, but I will later on tonight.


2H4



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User currently offlineTrent900 From United Kingdom, joined Dec 2003, 541 posts, RR: 0
Reply 13, posted (9 years 10 months 1 week 6 days 22 hours ago) and read 4420 times:

The thing I'm worried about is a fire inside the fuselage. If you had 2 identical fuselages as in size but one made of composite and the other standard aluminium, which one would last the longest if there was a fire? Would the composite let off more toxic fumes etc, being as though the melting point is much lower?

If the aircraft was unfortunately in a slow speed accident I'm sure a composite body would be more likely to break into pieces rather then crumple up. Not being an expert in this field I don't really know.

T.


User currently offlineViveLeYHZ From Canada, joined Dec 2004, 194 posts, RR: 9
Reply 14, posted (9 years 10 months 1 week 6 days 15 hours ago) and read 4354 times:

Trent900,

As for the fire resistance of aluminum and composite materials, the two have poor properties in this department, with aluminum being marginally better than composites. I just want to make it clear that I am strictly talking about resistance to fire/flames, and NOT high-temperature applications (say, near 200C, where aluminum wins).

So, to address the issue you raised above, depending on the size of the aircraft and the number of emergency exits, the aircraft will be designed to a given fire rating. The large the aircraft, the longer it takes to evacuate, the higher the fire rating (the same holds for buildings, high-rise vs. house, in fact this is why wood can not be used for buildings over 4 stories.) Both composites and aluminum would only last minutes under intense flame.

In the case of a fire event, unless fire retardant paint is sprayed in the structural parts, or in the case of composites, unless fire retarding agents are added to the resin, the structural part will melt (aluminum, thermoplastic composites, even steel after prolonged exposure) or burn (thermosetting composites, by far the most common composites) very quickly, and the structural part WOULD NOT pass the requirements of fire safety codes. The objective of code requirements is NOT to make the structural components fire proof, but rather provide occupants with enough time to evacuate before total failure of the structure.

On the structural side, even though most composites are brittle, it is not difficult to design composite parts (fuselages for example) that can withstand substantial impact loads and stay in one piece, often at huge weight and size savings over metals. Composites are stronger, stiffer and far lighter.

Did I answer (or even come close to answering) your question ? I get too excited when I talk about this stuff, I get carried away. Sorry.  Smile

Cheers,
ViveLeYHZ


User currently offline2H4 From United States of America, joined Oct 2004, 8956 posts, RR: 60
Reply 15, posted (9 years 10 months 1 week 6 days 12 hours ago) and read 4305 times:
AIRLINERS.NET CREW
DATABASE EDITOR

...From http://www.ipt.arc.nasa.gov/nanotechnology.html:

Nanotechnology is the creation of functional materials, devices and systems through control of matter on the nanometer length scale (1-100 nanometers), and exploitation of novel phenomena and properties (physical, chemical, biological, mechanical, electrical...) at that length scale. For comparison, 10 nanometers is 1000 times smaller than the diameter of a human hair. A scientific and technical revolution has just begun based upon the ability to systematically organize and manipulate matter at nanoscale. Payoff is anticipated within the next 10-15 years.



Where nanotechnology can help:

Nanoelectronics and Computing
- Petaflop computing
- Ultrahigh density storage 1015 bytes/cm2

Integration of computing, memory, sensing and communication

Structural Materials
- Microspacecraft
- Self-healing, multifuntional materials





...From http://www.eastonbike.com/TECH_FAQ/tech_cnt.html:

Nanotechnology is the next frontier in scientific research and advanced manu-facturing. Nanotechnology deals with the manipulation of materials on an atomic or molecular scale measured in billionths of a meter (nanometers). Scientists worldwide are spending countless man-hours and billions of dollars researching uses for nanotechnology in the areas of electronics, medicine, robotics and structural reinforcement.

The weakest areas in a traditional carbon-fiber component are the tiny spaces between the fibers that contain only resin. To radically improve strength and toughness in these critical areas, Easton Scientists have developed an innovative Enhanced Resin System using carbon nanotubes (CNT). Carbon nanotubes are an array of carbon atoms arranged in a pattern of hexagons and pentagons (similar to the pattern found on soccer balls). These structures can be manufactured in tubular shapes one billionth of a meter in diameter, hence the name nanotube. Carbon nanotubes have been called “the strongest fiber that will ever be made”. Nanotubes have a strength-to-weight ratio orders of magnitude greater than steel.

Easton’s proprietary process impregnates the resin/fiber matrix with evenly distributed carbon nanotubes. The addition of real carbon nanotubes greatly improves the toughness and strengthens Easton’s already legendary components.











...From http://www.pa.msu.edu/cmp/csc/nanotube.html

Carbon nanotubes, long, thin cylinders of carbon, were discovered in 1991 by S. Iijima. These are large macromolecules that are unique for their size, shape, and remarkable physical properties. They can be thought of as a sheet of graphite (a hexagonal lattice of carbon) rolled into a cylinder.

These intriguing structures have sparked much excitement in the recent years and a large amount of research has been dedicated to their understanding. Currently, the physical properties are still being discovered and disputed. What makes it so difficult is that nanotubes have a very broad range of electonic, thermal, and structural properties that change depending on the different kinds of nanotube (defined by its diameter, length, and chirality, or twist).

Simply put, carbon nanotubes exist as a macro-molecule of carbon, analagous to a sheet of graphite (the pure, brittle form of cabon in your pencil lead) rolled into a cylinder. Graphite looks like a sheet of chicken wire, a tessellation of hexagonal rings of carbon. Sheets of graphite in your pencil lay stacked on top on one another, but they slide past each other and can be separated easily, which is how it is used for writing. However, when coiled, the carbon arrangement becomes very strong. In fact, nanotubes have been known to be up to one hundred times as strong as steel and almost two millimeters long! [17] These nanotubes have a hemispherical "cap" at each end of the cylinder. They are light, flexible, thermally stabile, and are chemically inert. They have the ability to be either metallic or semi-conducting depending on the "twist" of the tube.










So there you have it, guys...perhaps the most revolutionary structural material ever discovered.

Buy stock now.

 Big grin



2H4



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User currently offline2H4 From United States of America, joined Oct 2004, 8956 posts, RR: 60
Reply 16, posted (9 years 10 months 1 week 6 days 9 hours ago) and read 4258 times:
AIRLINERS.NET CREW
DATABASE EDITOR

Hot off the press:

Researchers uncover secrets behind nanotube formation

11 February 2005

Nanotubes are ubiquitous in the world of science. Although several methods for making them exist, little is known about how these techniques physically produce the hollow fibers of carbon molecules known as nanotubes, that is until now. A multinational team of scientists has discovered that multi-walled carbon nanotubes made by the pure carbon arc method are, in fact, carbon crystals that form inside drops of glass-coated liquid carbon. The research appears in the 11 February 2005, issue of the journal Science, published by the AAAS, the science society, the world's largest general scientific organization. See http://www.sciencemag.org, and also http://www.aaas.org.

Full text at http://www.eurekalert.org/pub_releases/2005-02/giot-rus020905.php





Another article:

Liquid carbon plays role in nanotube formation

11 February 2005

Researchers have discovered that the formation of multiwalled carbon nanotubes in a pure carbon arc involves liquid carbon. They believe that the nanotubes formed by homogeneous nucleation inside droplets of the liquid.

"We were doing research on the electrical transport properties of carbon nanotubes when we noticed that the nanotubes had these little beads that looked like liquid drops on them," said Walt de Heer of the Georgia Institute of Technology. "We hope our results will open up the whole question of nanotube formation again."

Full text at http://www.nanotechweb.org/articles/news/4/2/7/1


Nanotubes coated with glassy drops of carbon poke through the surface of a column housing nanotubes.





Glassy drops of carbon coat the fibers that house nanotubes after their synthesis with a carbon arc.





Ok, that's all. I'll shut up now.


2H4



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User currently offlineZvezda From Lithuania, joined Aug 2004, 10511 posts, RR: 64
Reply 17, posted (9 years 10 months 1 week 6 days 4 hours ago) and read 4206 times:

My hat is off to both ViveLeYHZ and 2H4 for engaging in such a civil and elucidating argument. Welcome both to my respected users list!  Smile

User currently offlineViveLeYHZ From Canada, joined Dec 2004, 194 posts, RR: 9
Reply 18, posted (9 years 10 months 1 week 5 days 18 hours ago) and read 4130 times:

Zvezda,

Welcome both to my respected users list!

Thank you buddy. I am glad you didn't find this stuff boring.

2H4,

Thank you for the links. I have only recently decided (well, I guess my supervisor told me) to explore the advantage of embedding nanotubes in adhesive joints as a mean of improving fracture/fatigue resistance. Our initial course of action was to test joints with milled carbon fibers and whiskers, both have the effect of bridging and arresting micro-cracks in the joint, and retarding crack growth. But it seems like nanotubes is where the future of composites is.

I will have to start looking for suppliers of this material soon, any help/advice will be greatly appreciated.

Yours,
ViveLeYHZ


User currently offlineSchooner From United Kingdom, joined Oct 2001, 139 posts, RR: 0
Reply 19, posted (9 years 10 months 1 week 5 days 18 hours ago) and read 4111 times:

Well that discussion has made me feel really intellectually deficient  Sad ! Interesting stuff.

Cheers.



Untouched and Alive
User currently offlineN200WN From United States of America, joined Feb 2005, 784 posts, RR: 6
Reply 20, posted (9 years 10 months 1 week 5 days 17 hours ago) and read 4090 times:

Well that discussion has made me feel really intellectually deficient ! Interesting stuff.

Same here...but I thoroughly enjoyed it! Thank God there are people with that kind of knowledge and intellect that make it possible for people like me to live in a modern world.

And 2H4, I sure hope to see you flying a Southwest jet someday. Where on earth can I get a copy of that Southwest aircraft on your profile? It's great!



User currently offlineViveLeYHZ From Canada, joined Dec 2004, 194 posts, RR: 9
Reply 21, posted (9 years 10 months 1 week 5 days 15 hours ago) and read 4058 times:

Schooner and N200WN,

I know the feeling.  Smile

My first job ever was as a research assistant after my second year in college. The topic was on the retrofitting of reinforced concrete bridge beams with fiberglass composites. I had to get myself familiar with composite materials, and also the Finite Element Method to analyze the concrete structures. In short, it was very intimidating at the start, but here I am five years later, doing my PhD on composites.

Just for the record, I am writing this reply while taking a break from laying-up fiberglass polyester composite. This stuff sure is very messy.

The subject in itself is not very difficult, and if you guys want a brief introduction on composite materials, here are two good link I found from a basic google search:

http://www.engr.ku.edu/~rhale/ae510/compintr.pdf (nice applications photos)

http://www.colorado.edu/ASEN/asen4012/LectureNotes/Composites.pdf (brief introduction, not too technical)

Cheers,
ViveLeYHZ


User currently offline2H4 From United States of America, joined Oct 2004, 8956 posts, RR: 60
Reply 22, posted (9 years 10 months 1 week 5 days 8 hours ago) and read 4016 times:
AIRLINERS.NET CREW
DATABASE EDITOR

Zvezda, thanks! Like Vive said, it's nice to know there are other dorks like me out there.  Smile



And 2H4, I sure hope to see you flying a Southwest jet someday.

N200WN, thanks for the kind words...that's really cool of you to say. I'll always have a place in my heart for WN, even if I never make it there. I look forward to the day I can join the family. As for the WN Sonic Cruiser pic, check your email.  Big grin



Schooner, the problem isn't your perceived intellectual deficiency. The problem is the huge lack of simple, straightforward information about nanotechnology. The best analogy I've come up with to describe nanotubes is this (Vive, please correct me if this seems inaccurate to you):

Imagine holding a stack of several loose sheets of paper. Structurally, the stack of paper is absolutely useless. You can put stuff on top of it, but anything else will cause the stack of paper to flex around and spill all over the place. You can't use stacks of paper to build walls, ceilings, etc.

Okay, now take the same raw material (paper), and put a corrugated layer between two sheets. Now you have cardboard. Cardboard doesn't support a ton of weight, but compared to loose sheets of paper, you can build anything. It all comes down to internal structure. That's the concept behind nanotubes. Currently, most carbon applications are using what amounts to loose sheets of paper in the form of resins. Nanotubes are to current resins what cardboard is to several loose sheets of paper.

This early in the game, it's all just a bunch of scientists talking to scientists. As a result, it's almost impossible to find information in plain English. "Almost" being the operative word. I did some digging, and came up with some really well-written info for you:

Below are some FAQ's I think you'll enjoy reading. They are from Easton (http://www.eastonbike.com/), a cycling component manufacturer, and Zyvex (http://www.zyvex.com/), a nanotube sales firm:

_________________________________________________________________

1. What does Zyvex do?

Zyvex provides nanotechnology solutions for short-term and long-term real world applications. Zyvex’s vision is to become the leading worldwide supplier of tools, products, and services that enable adaptable, affordable, and molecularly precise manufacturing. Zyvex currently offers nanotechnology products in the areas of materials, tools, and structures for a wide variety of markets, including Aerospace and Defense, Healthcare and Medical, and Electronics and Semiconductors.



2. What is Nanotechnology?

The word “nano” in nanotechnology derives from the term “nanometer”, which is one-billionth of a meter. Molecular nanotechnology is the manipulation of matter at the atomic, molecular, or macro level (on the length scale of approximately 1–100 nanometers). Zyvex delivers nanotechnology solutions via three major market-driven platforms: materials, tools, and structures. Materials that are characterized by structural features less than 100 nm can be broadly classified as nanomaterials; these serve as the basis for Zyvex’s NanoSolve™ materials product line. The NanoWorks™ tools product line and product portfolio includes the entire spectrum of enabling technologies that promote visualization, manipulation, and engineering at the nanoscale. Structures result from controlled synthesis and subsequent assembly of material building blocks with new and improved properties and functionalities.



3. What are Carbon Nanotubes (CNTs)?

Carbon nanotubes are layers of graphite seamlessly wrapped into cylinders which are a few nanometers in diameter, and approximately 10-20 microns long. Therefore, the length-to-width aspect ratio is extremely high. Both the graphitic nature of the material and their large aspect ratio provides enhanced physical properties, which exceeds most common filler materials.



4. What are the physical properties of CNTs?

SWNTs have reported tensile strengths 20 times that of Chromoly steel with 1/6 the weight. In addition, carbon nanotubes significantly improve the electrical and thermal conductivities of commercial polymers. The conductivities of Zyvex’s CNT composites are at least several orders of magnitude higher than those of insoluble CNT composites, particularly at low nanotube loading levels. In addition, carbon nanotubes offer the ability to enhance the mechanical and structural properties of composites. Examples of this data can be obtained by reading our application notes at www.zyvex.com/Products/appsnotes.html.



5. Why was Zyvex the right technology choice for Easton?

Zyvex was able to meet Easton’s needs for rapid integration of CNTs into an existing composite material. Zyvex is committed to commercializing nanotechnology today and Easton is an early adopter of innovative new technologies. By working together, Easton and Zyvex were able to bring real nanotechnology to actual production.



6. How many CNTs are in the handlebars?

Loading levels are considered proprietary by Easton.



7. What performance improvements have you seen?

Easton’s published results show a 25% increase in bending strength with good toughness.



8. I heard CNTs were expensive, how were you able to put it into large scale production?

Properly treated CNTs can be cost effective for numerous applications. Easton had a cost target associated with the integration of CNTs into their products and Zyvex was able to meet that target. Our customers have discovered that Zyvex’s NanoSolve™ is cost-effective for a number of immediate applications. Excellent dispersion requires significantly fewer nanotubes to gain increased material performance, compared to other commercially available nanomaterial products.



9. What is the host material you are using?

Zyvex functionalizes various forms of carbon nanomaterials for a variety of host materials. Easton’s host matrix is proprietary information.



10. Are you using SWNT or MWNT?

Zyvex’s chooses the best material for each application. The material chosen for Easton’s first application is proprietary information.



11. How do CNTs compare to Nanoclays?

Easton has been using nanoclays for processing ease for over 10 years. They also discovered CNTs exceed the performance of nanoclays to enhance the physical properties of the matrix.



12. Do you have plans to use this technology in other products?

Zyvex will continue to introduce additional NanoSolve™ products for different applications and industries.



13. What is the relationship between Zyvex and Easton?

Zyvex and Easton have partnered to bring a real nanotechnology product to market, quickly delivering the technology from an R&D phase to actual production. This is the first commercially available carbon nanotube product in the United States bicycle market where an average customer can go into a store and purchase an offthe-shelf product containing carbon nanotubes.



14. What is unique about Zyvex?

Zyvex actually incorporates nanomaterials, such as carbon nanotubes, into commercial applications. CNTs have exceptional physical properties, but incorporating them into other materials has been inhibited by the surface chemistry of carbon. Problems such as phase separation, aggregation, poor dispersion within a matrix, and poor adhesion to the host must be overcome. Zyvex solved these problems by developing a new surface treatment technology called Kentera™ that optimizes the interaction between CNTs and the host matrix.



15. What are Zyvex’s NanoSolve™ products?

Zyvex’s NanoSolve™ Materials product line delivers nano-additives, enhanced materials, process consulting, and finished goods to a growing list of customers, and an expanding list of real-world applications. Zyvex additives can deliver enhanced thermal, electrical, or mechanical properties by selectively transferring the superior intrinsic properties of carbon nanotubes into composite materials. Current offerings include:

NanoSolve™ Additives

• Functionalized MWNT or SWNT in solvents
— Chloroform, Chlorobenzene, Dichloromethane, 1,2-Dichloroethane, 1,1,2,2-Tetrachloroethane, Acetone, Dioxane, Ethyl Acetate, Methyl Ethyl Ketone, Isopropanol, Anisole, NMP, DMF, Ethanol, THF, Toluene, Xylene, and Water
• Functionalized MWNT or SWNT in Epoxy
• Functionalized MWNT or SWNT in Polyurethane or Polyurea


NanoSolve™ Enhanced Materials

• NanoSolve™ enhanced epoxy resins
• NanoSolve™ enhanced polyurea pre-polymers
• NanoSolve™ enhanced polyurethane pre-polymers

16. What is Zyvex’s Kentera™ technology?
Kentera™ technology is a non-damaging surface treatment technology that provides excellent dispersion of CNTs in various solvents (including water) as well as enhancing the interaction between the CNTs and the host matrix.



17. How does Kentera™ work?

Kentera™ is a functionalization “bridge” which contains two major components. One component non-covalently adheres to the nanomaterials; the other easily customizes to any application. This technology allows Zyvex to quickly adapt to our customer’s needs, providing early adopters with rapid time to market — and a very compelling product. We have designed our additive for numerous solvents and host materials.



18. What are Zyvex’s advantages in relation to CNT nanocomposites?

Zyvex’s NanoSolve™ product line offers cost-effective CNT technology, large scale delivery for rapid time to market, resolution of CNT processing bottlenecks, and a unique technology retaining the intrinsic properties of the CNTs.



19. What solubility advantages can Zyvex offer?

Zyvex’s Kentera™ technology allows excellent dispersion in various solvents and matrix materials. We can solubilize carbon nanotubes with solvent or without solvent allowing process ease and incorporation into existing product formulations.



20. Does Zyvex make nanotubes? Whose do you use?

Zyvex does not manufacture nanotubes. We have identified a significant number of worldwide vendors for both SWNTs and MultiWall Nanotubes (MWNTs), and have supplier relationships with many of them.

Our business is to make nanotubes easier to process and use in products, and to help our customers pick the right nanotubes and the right processes for their application. Since we are not obligated to use a particular type of nanotube or manufacturing technology, we objectively pick the optimal manufacturer for a particular application.



21. What is the Zyvex CNT Supply Chain?

As part of its mission to achieve molecularly precise manufacturing, Zyvex takes an active role in defining and qualifying nanomaterial supply chains for its customers. Through our Supply Chain Certification program, Zyvex ensures that you receive the quality materials you need, on a reliable delivery schedule that synchronizes with your own processes. Zyvex’s comprehensive program verifies quality and batch-to-batch consistency using SEM, TPO, TGA, and a number of standard analytical tests.



22. Is large scale manufacturing and mass production a problem for Zyvex?

Zyvex’s processing technology supports global industrial production. We offer quality control support, scalability to large volumes, process consulting, and finished goods.



23. What applications are ideal for NanoSolve™?

Zyvex technology can be incorporated into most polymer matrices, including epoxies, adhesives, polyurethanes, and thermoplastics. We also offer co-development contracts to develop customized formulations for specific matrices.
Some markets that find this technology advantageous include:

• Epoxy and engineering plastic composites
• Thermal management (interface materials, spacecraft radiators, avionic enclosures, and printed circuit board thermal planes, etc.)
• Aircraft, ship, and automotive structures
• Improved dimensionally stable structures for spacecraft and sensors
• Reusable launch vehicle cryogenic fuel tanks and unlined pressure vessels
• Packaging of electronic, optoelectronic, and microelectromechanical (MEMS) components and subsystems
• Medical materials
• Sporting goods
• Composite fibers



24. How do we determine if the technology/capabilities will meet our needs?

Our technical sales personnel will be happy to discuss your needs and determine which Zyvex capabilities which are right for your application. Please contact Lance Criscuolo at 972.235.7881 (ext. 224) or by email at lcriscuo@zyvex.com.



25. Is NanoSolve™ stable?

Zyvex NanoSolve™ products are stable for many weeks to months.



26. Do you have any restrictive materials agreements?

We want you to freely use NanoSolve™ in your own applications and buy more from us. Therefore, we do not restrict your uses of this material.



27. I thought Zyvex was working on atomically precise manufacturing and NanoWorks™ tools – how is this related?

Actually, our NanoWorks™ materials support atomically precise manufacturing. We are committed to commercializing all nanotechnology breakthroughs.

When preliminary tests of our nanotube solutions showed material properties better than alternative dispersion approaches, we began to move this technology out of the lab and into customer’s hands.

The underlying technology in NanoSolve™ materials allows us to molecularly engineer the properties of the solubilizing agent to suspend tubes in a variety of solvents. Additionally, the interaction of the tubes with the host material can be designed to achieve a range of properties in the resulting composite material system once the solvent is removed.

This “platform technology” uses existing chemistry to tailor nanomaterials at the molecular scale to solve real-world materials problems. Solving real-world problems with nanotechnology is exactly why Zyvex was started, and we are pleased to offer an innovative nanomaterials product line.



28. Who do I contact for more information?

For more information, please contact Lance Criscuolo at 972.235.7881 (ext. 224) or by email at sales@zyvex.com.

_________________________________________________________________



Finally, ViveLeYHZ, here is a list of nanotube suppliers for you:

Of course, http://www.zyvex.com. They appear to be one of the most useful firms out there.

http://www.flash.net/~buckyusa

http://carbolex.com

http://cnanotech.com

http://www.fibrils.com

http://www.nano-lab.com

http://carbonsolution.com

http://www.gzenergy.com

http://www.mercorp.com

http://www.nanocarblab.com

http://www.nanocs.com

http://www.nanocyl.com/activities/index.php

http://www.nanoledge.com

http://www.e-nanoscience.com

http://www.sesres.com/Nanotubes.asp

http://www.sunnano.com

http://www.rsphysse.anu.edu.au/nanotube

http://www.thomas-swan.co.uk/pages/nmframeset.html

http://www.apexnanomaterials.com

http://www.timesnano.com/default.html

http://www.nanotubesx.com/draft/related-sites.html


...And here is a company that produces software for automated analysis of nanotube images:

http://www.simagis.com/nanotubes.htm


Are you into cycling at all? My experience with composites stems from cycling technology, as you probably have already guessed. I'd be interested to hear a PhD-type's perspective on frame design. It would be fun to compare and contrast your significantly more educated viewpoints with my experience using and working with them.

In my opinon, Trek's OCLV line of carbon bikes eclipses the competition. They use a lugged frame design, and a proprietary bladder/mold process. You can see the bikes at http://www.trekbikes.com, and you can see the patent information at http://www.closedmold.com/patents.htm.

Any thoughts would be welcome.

This thread has definitely strayed off-topic (guilty as charged), but I've certainly enjoyed it. After all, we've got all this information, and not a single mention of NWA DC-9s or A vs. B...

Keep up the great work, guys!

 Big thumbs up


2H4



Intentionally Left Blank
User currently offlineSchooner From United Kingdom, joined Oct 2001, 139 posts, RR: 0
Reply 23, posted (9 years 10 months 1 week 5 days 2 hours ago) and read 3972 times:

Thanks for that! I`m afraid that if I try to take too much of it in it`ll push out other stuff from my brain & I`ll forget how to breath or fly (need to remember, stick back, cows smaller, stick forward cows bigger!).

Cheers.



Untouched and Alive
User currently offlineTrent900 From United Kingdom, joined Dec 2003, 541 posts, RR: 0
Reply 24, posted (9 years 10 months 1 week 5 days ago) and read 3930 times:

ViveLeYHZ,

Thanks for all that info  Smile Its now got above my head so i'll just sit back and just think.  Smokin cool

T.


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