Technical note: 5 micron fibres found in an ultrafine grower lot - implications for diameter distribution measurement

Abstract

There has been debate in IWTO Technology and Standards Groups in the past about whether ultrafine fibres below 8 µm reported in OFDA fibre diameter distributions do actually exist. This note describes scanning electron microscope measurements made on a sample from a typical specialty grower lot to confirm the existence of fibres on which "diameter" measurements can be made down to 5 µm. Using the most recent Laserscan calibration regime, both OFDA and Laserscan certification gave similar measurements of MFD and SD on this sample, although as expected, the OFDA reported more fibres in total below 10 µm, including some at 5 µm. We conclude that these fibres do actually exist.

It is suggested that despite differences in diameter distribution shape and fine tail reporting, the similarity in certification results may now render the question as to which instrument is "more correct" one of purely academic interest. 

Note:

A critique of this paper was published in the AWTA Ltd Newsletter in May 2001.

Citation

"Technical note: 5 micron fibres found in an ultrafine grower lot - implications for diameter distribution measurement", B. P. Baxter, Report RWG02, Technology & Standards Committee, Raw Wool Group, IWTO Shanghai Meeting, May, 2001.