Carbon fiber technical specs

General Composites Discussions Products Talk
#1

I write down a list of technical specifications for a type of 200gsm 3K 2x2 twill carbon fiber fabric:

Tensile Strength (MPa):4452
Tensile Modulus (GPa):235
Tensile Modulus (msi):34200
Tensile Modulus (kgf/mm2):24100
Elongation (%): .5
Mass per Unit Length tex (g/1000m):200
Fiber Density (g/cm2):1.786
Size Content by Mass (%):1.22

This is the specs i received from a supplier of carbon fabrics.
Because i have not ever reviewed in depth the mechanical characteristics of carbon fiber, could anyone tell me if thi type is any good? Could you give me the specs of another carbon fiber and compare them?

#2

I’m curious myself to know what makes Toray brand dry carbon fiber better than Chinese made dry carbon fiber?

I think it’s something like what the fibers were actually made of… pitch or ?

#3

yeah, check with each manufacture of CF, and they will have the details for public view. PAN is better than pitch, and obviously more expensive :slight_smile: I need to step on the courses here so I can learn what EXACTLY strength and modulus, and stuff means :slight_smile:

#4

Most carbon fibers are going to have very similar properties, unless comparing high strength to high modulus. Otherwise, it will be tough to tell apart by simply trying to flex cured parts.
Resins are going to have more of an effect as they do have a wide range of properties. My shop uses urethanes with tensile strength of 8,000, vinylester with 11,00 and epoxies with 13,000. A change in resin definitely can be noticed by trying to flex a cured part.

Basically, tensile strength is how strong the material is if you try to pull it apart. How much force it takes. This sort of goes along with elongation, as that measures how much the material stretches before it breaks. Low elongation = brittle. It may take a lot of force to actually make it fail, and then it will do so violently. Other materials may be less brittle (more elongation) and fail gradually.

#5

Mechanical engineering tutorials are good for those who need them, but what i asked was whether the carbon i got the quote for can be compared with good results to other carbon you might have used in the past and know their final properties. Thanks! :slight_smile:

#6

My answer was to help you figure it out. Again, the properties are very similar between most carbon fiber suppliers. YES, it will give results that are the same as others you might have used. Unless you take it to a lab, you will not see a difference.

#7

It would help if you could point me out to a carbn fiber which will give less brit le characteristics. For example i have found a carbon with 0.5% elongation (the one in the first post) and another one with 1.5%

#8

All carbon fiber laminates are going to be more brittle than kevlar or glass. But it doesn’t matter unless the part breaks. If it’s strong, it should not break, so this shouldn’t matter.

I think you’re looking for something that doesn’t exist. If you wan’t a part to be more flexible, use a resin that has the properties you want.

#9

yes, resins make a major difference in the part.
I’m sure most modeling software with composite anaylsis should have software where you can plug the fabric/resin specs in, and see what you get. I think that is the best way to go. Then you can tailor exactly what you need!