May be it can help you. Plz check the standard methods given in the link.

http://composite.about.com/library/glossary/f/bldef-f2200.htm

Thanks Yasir.

However this does not work for us. We need a non destructive test for our prepreg material.

Regards,

Http://jrp.sagepub.com/content/8/6/627.short

You can measure ultrasound velocity. Ultrasound velocity depends on the volume fraction of resin and fibres. However it does also depend on fiber distribution. This means that you need to know how is the fibre distribution in your prepreg before you estimate resin volume fraction from ultrasonic velocity data, but if you know this data or, alternatively, if you can calibrate the method, it will work quite well. It is completely nondestructive and fast.

Another option is to measure both velocity and impedance, then you can wotk out density and hence resin volume fraction without any additional information or calibration..

An advantage is that there are techniques where contact with the sample is not neccesary (when this supposes a problem in terms of contamination).

Thanks for the interesting answer Gomez. Can you provide the name of a couple of companies that either provide the metrology equipment or services to measure the resin content with the techniques you have mentioned?

Thanks,

There are a lot of companies that provide the equipment to perform ultrasonic velocity measurements. Look for companies dealing with ultrasonic NDT equipment. Examples are Panametrics (Olympus NDT), Krautkramer, Sonatest, Dasel, Lecoeur, etc. Alternatively what you nedd is a waveform generator a couple of transducers and a oscilloscope. In general you can use any ultrasonic thickness gauge for this purpose and measure time of flight instead of thickness. You first measure the velocity and then you have to work out the resin volume fraction (which can, in some cases, be not completely straigforward). In all these cases you have to couple the ultrasonic transducer to the test material using a coupling gel or a water immersion tank.

If you are dealing with plates (laminates) you can use the procedure we published in: -Simultaneous determination of the ultrasound velocity and the thickness of solid plates from the analysis of thickness resonances using air-coupled ultrasound.

Tomás E Gómez Alvarez-Arenas. Ultrasonics 09/2009; 50(2):104-9.

In this case the advantage is that you can obtain directly both velocity and density so you can obtain the resin content directly. An additional advantage is that contact with the material is non neccesary (neither immersion in water) so it can be faster and is completely non invasive. If you go for this option we can produce the required air-coupled wideband transducer and the whole system for you or we can test it for you in some samples of interest.

How about density? At least if the fibers are glass this should work. Just use Archimedes' law (dry and immersed weight). Also aramids, C-fibre shuld be OK, cellulose reinforced is much more difficult I expect. Asbestos is not popular anymore for some reason. If there is air in the prepreg this method is totally unreliable of course.

How about using 3D non contact surface roughness measurement (laser)? 

There are many commercial table top machines available

You can then do an contrast analysis to separate resin and fiber contour. By measuring the corresponding voxels, you can find the relative volume fraction.

Just a thought..

Regards,

Vasan 

Hi there I am a student doing my diploma. I want to understand why do we determine the resin fraction. I am using CFRP as my sample. i have done both TGA and the resin burn off method to determine my resin fraction.