Talk:Carbon-fiber reinforced polymer/Archives/2013

Long term disposal, environmental and health safety (100+ years) concerns
I started a bit of discussion on what might be in a possible section covering this here. http://en.wikipedia.org/wiki/Talk:Carbon_fiber#Disposal_.2F_Safety_section_needed

Now it may sound a bit alarmist but how many consumer even know they'd need to specially dispose of their hobby equipment made from composites like CFRP? I bet very few even if many EU countries have had it in the law for 4 years as that one article claims.

Civil Eng Applications
I just added this section. It's vaguely factual, but any assistance from a higher expert would be greatly appreciated. --Sjkebab 03:17, 14 October 2005 (UTC)

I've put in some detail, mainly on retrofit to reinforced concrete, which is the main application in the UK. I've mentioned ductility enhancement by wrapping (which I believe is the main application in the US). I've taken out the claim that CFRP has incredible stiffness and limits bridge deflection, and put in a section saying why that's not true.

I'd like to know the source of claims re. CFRP being used for reinforcement and especially prestressing offshore - CFRP prestressing strand would be fantastic if someone could make a reliable anchorage, but though I know academics who've been at it for years, I've not yet seen a good system. I've toned down the claims but left them in place (because as soon as someone does crack the anchorage problems, it will be fantastic application for the material).

Likewise, the article claims aramid FRP is cheaper. I think this is not true. I think it's doubly not true when you consider stiffness and find you need twice as much aramid plate as carbon plate - the only times I've ever used aramid plates for retrofit is where I needed an electrically non-conductive plate. I've left these claims in place - it's possible that pricing differs in other markets.

Achrn (talk) 14:51, 29 March 2009 (UTC)

Style concerns
Is there any reason that the article alternates between "fiber" and "fibre"? Can this be cleaned up to use the American "fiber" throughout without offending anyone?

Comment: Im not really botherd whether it is spelt fibre or fiber, so fiber is ok, but could an automatic link be created to send people to carbon fiber for those who type in carbon fibre, as if is difficult with two articles around.

Move

 * Comment: The new name should, according to WP:NC, be carbon fiber reinforced plastic (or carbon fibre). Prefer lowercase words (it's easier to link inline in article text). Hyphenation is a little more difficult. --Christopherlin 21:27, 3 March 2006 (UTC)

Comment: This move seems to me to be counter productive, while carbon fiber is mostly used in reinforcing plastics or in making composites, carbon fiber can be used for other purposes and a reader may be interested in the properties of carbon fiber itself. Also a merge will decrease the ammount of detail on the actual synthesis of the carbon fiber and also the other uses will no longer be displayed. This seems to be like merging the article for rebar into the article for concrete.

Comment Against a merge. What would you do for metal matrix composites, for example, which can (if I'm remembering correctly) be made with carbon fibre embedded in the matrix. An example of confusion on a page I saw recently - the writer referred to carbon fibre as fireproof. Completely accurate for carbon fibre. Trouble was, the piece was actually about a carbon fibre composite component which in that particular application is not fireproof. Better to be clear on the difference. 195.137.77.175 00:42, 21 March 2006 (UTC)


 * Oppose merger. If anything, merge specific into more general.  Gene Nygaard 02:00, 10 April 2006 (UTC)

Automotive section - flexi wing
This section needs to make it clear why the aero flexi wing has got anything to do with CFRP. I believe that the connection is that Ferrari (and others) have produced a very carefully designed layup to give exactly the deflection they want and only in the right direction. You may also find on further investigation that the idea goes back further than that. The idea was definitely around about 5 years ago (by BAR, I think) and ITV commentator Martin Brundle made reference to having a flexi rear wing on a Ligier in the early 1990s during his commentary on the 2006 Malaysian Grand Prix.

Material properties?
Obviously the material properties of CFRP will vary depending on the weave, etc. But this page should list ballpark stiffness and yield stress for common configurations. 71.245.131.163 02:14, 18 May 2007 (UTC)

More info Many ways carbon fiber parts can be made all are the same as fiberglass or any composite. Prepreg. Prepreg has tons of miss conceptions. Most companies unless they are a very small one make their own prepreg. What they go is have the roll of CF feed through a tank of resin. Its a very slow resin that will remain uncured for hours and have a pot life in excess of 4 hours. Once its feed through the tank 2 rollers press down and squeeze out most of the excessive resin.

Comment - Actually, most aerospace companies buy their prepreg from other companies that specialize in materials. Almost all of the CFRP for the Boeing 787 will be purchased from Toray. Also, the description of the prepregging process is mostly incorrect. The resin is generally first cast onto a paper transfer medium and then pressed into the dry fiber. —Preceding unsigned comment added by 64.173.185.182 (talk) 23:13, 26 January 2009 (UTC)

Another way is the tradition wet layout. This states where you put the cloth in the mold and brush on the resin. Then traditionally you use rollers to compress the sheets togther. Very little control of the resin to cloth ratio is had

The other way is called RTM or resin transfered molding. This is when the cloth is layed down Completely DRY. Ontop of the cloth a breather film is applied which feels like thick plastic wrap but with tons of tiny holes in it. Its made of a nonstick plastic that resin cannot bond to. On top of that a whick cloth is made which is normally just a fluffy non woven polyester fabric.

Now the whole mold is vacuumed bagged. Now what happens is with a series of tubes going into the back at tragic locations connect to a tank of resin. as the air is drawn out the resin is sucked in. Its done to save time and kills 3 birds with one stone. It compresses the sheets together. It applies the resin. It removes the excessive rein.

When it comes to vacuum bagging its highly desirable wither its wet or Dry set up or prepreg. While not needed for all systems to make the parts cure. This is what gives any product its strength. It forced the parts together like a clamp but with a even pressure of every square inch of the surface. It also forces out the excessive resin through the small holes the breather film.

Now when people use an autocav its a even better step the pressure in the chamber and the vacuum in the bag creates even more pressure the equivalent to 2 atmospheres or more. And with a slow set resin it speeds up the cure process with the added heat. The quicker the resin cure time the more heat it makes so with slow speed resins you really need to add heat. Infact anyone experiment with carbon fiber i will warn you against using a relitivly high pot life resin which is 30 min or less. If you mix more then a pint at a time you put your self in danger of serious injury.

Just with a experiment I mixed half a half a gallon of expired resin with half a gallon of the curing agent. Remember this stuff was a premix with some filler to keep it to a 1:1 ratio. I wasted it because some of it was used and it sat unused for a year and i wouldn't trust my life with potentially tainted product Pretty much the heat built up so much it melted the 5 gallon bucket and singed the plywood table it was on and produced a good amount of smoke. Thats a temp of well inexcess of 300 degrees and near twords the ignition temp of wood. Just imagine what that would do to your flesh if you spilled some one you. Also the heat built up so much it was a highly crystallized structure thats very weak —Preceding unsigned comment added by 68.109.127.19 (talk) 18:11, 2 September 2007 (UTC)

I may overhaul this section soon. I have a reliable third edition of a text to consult. Dylan Hsu (talk) 15:09, 27 June 2012 (UTC)

Energy consumption
Mentions need to be made about the production process of CRP products and comparisons to Aluminium and Steels. Also, Whether there really is anything to gain from replacing Ally parts with CRP - In some cases this isn't true and sometimes doesn't make much of a weight difference - specifically, non stressed parts of automobiles, body parts. Anyone have more info on this. Ross 77.100.12.167 (talk) 22:53, 7 January 2008 (UTC)

Move
Someone decided to move this to 'Prepreg (PreImpregnate)' for completely unspecified reasons. If that user should decide to come here and dispute me rolling this back, I request he review Naming conventions (common names) before doing anything else. --Joffeloff (talk) 19:44, 9 March 2008 (UTC)

GFRP
since when has GFRP been an acronym for Graphite fibre reinforced polymer? grapite comes under the CFRP catagory. GFRP is Glass Fibre reinforced polymer and always will be. —Preceding unsigned comment added by 81.110.64.125 (talk) 10:24, 26 November 2009 (UTC)

Processing
Cutting or machining carbon fiber parts, such as tubing or rod, is a bit difficult. It shatters very easily and dust must be kept to a minimum. —Preceding unsigned comment added by Werhner (talk • contribs) 17:57, 3 April 2010 (UTC)

End of useful life/recycling
The article says "Carbon fiber-reinforced polymers (CFRPs) have an almost infinite service lifetime when protected from the sun, and, unlike steel alloys, have no endurance limit when exposed to cyclic loading." The sentence seems to give the impression that having no endurance limit contributes to infinite service lifetime. But the article http://en.wikipedia.org/wiki/Endurance_limit seems to say that an endurance limit is a positive characteristic that leads to high endurance (as long as amplitudes remain below the limit). So, your sentence makes no sense to me. If your point is rather that having no endurance limit leads to failure and ending up in landfill, I don't get that from the sentence.

75.23.69.42 (talk) 15:37, 22 March 2011 (UTC)

I believe my last edit should address the above (entirely legitimate) concern. In fact, the lack of a fatigue endurance limit (FEL) is, in and of itself, a drawback to CFRP materials and is not, as the prior language suggested, some advantage conducive to "almost infinite" service life. So I changed "almost infinite" to "long" and added the second paragraph to better address the FEL issue in a more balanced manner.

link broken
one of the external links is broken. the third I think. — Preceding unsigned comment added by 130.133.54.105 (talk) 11:50, 30 April 2012 (UTC)

Fibre is spelled wrong
please, somebody correct me if I am wrong in saying this, but every time I have ever seen it written, it has been spelled 'fibre', NOT 'fiber', as a result, I am concerned that there may be an enormous spelling mistake, and needed some confirmation/denial of this. — Preceding unsigned comment added by Ohdear15 (talk • contribs) 18:15, 7 August 2012 (UTC)
 * This is a difference between variations of english, see WP:ENGVAR for the gory details. Where I live, the dominant term is by far fiber, while the spelling fibre would be looked at funny. Tazerdadog (talk) 19:06, 3 February 2013 (UTC)

Density
Does anyone know where to find the density or an average density? It would be very useful to have on here. --Keizo 04:14, 26 April 2007 (UTC)

The density of the average carbon fiber/epoxy laminate is .06 lbs/cu inch —Preceding unsigned comment added by 64.173.185.182 (talk) 23:08, 26 January 2009 (UTC)

Honeycomb Image not CFRP
The image of the BMW i3 honeycomb structure appears to be some other material such as injection molded ABS, not CFRP. The frame upon which it is adhered is CFRP but not the honeycomb structure nor base. http://en.wikipedia.org/wiki/File:2013_IAA_BMW_i3_Honeycomb_structure.jpg — Preceding unsigned comment added by 153.162.252.48 (talk) 07:38, 3 November 2013 (UTC)