Search

The air-flow technique for the measurement of wool-fibre fineness has advantages over other methods because of its speed and convenience of testing. However, if the wool being tested is in the form of washed corings from greasy bales or corings from scoured bales rather than tops, the sample may contain impurities such as vegetable matter or sand and dust, and, although it is possible for such impurities to be removed, the treatment requires time and the continuous attention and judgement of a trained operator. The effect of the presence of impurities on the indicated mean diameter of wool fibres is therefore a matter of some importance, and an account is given in this paper of an investigation undertaken to study this effect. The theoretical basis of the influence of impurities on the indicated diameter is given, and it is shown that the experimental results are, in general, in agreement with the predicted values. Provided that the amount of vegetable matter present does not exceed 5% and coarse, sandy dirt is present to an amount not exceeding 1%, it is likely that the error in the indicated diameter resulting from the combined effects will fall in the range from 0 to +4.2%, i.e., the error would not exceed ±2.1% at the 95% probability level, which might be an acceptable figure for many purposes if an adjusted calibration were made. [ABSTRACT FROM AUTHOR]

There is an optimum value for both the quantity and the viscosity of a mineral oil added to wool before carding and gilling. This was assessed by force measurements in gilling and in rectilinear combing by determination of the minimum percentage noil and maximum mean fibre length of the top. Backwashing before combing results in a lower percentage noil and higher mean fibre length compared with non-backwashed controls. [ABSTRACT FROM AUTHOR]

An account is given of a study made by means of thin-layer chromatography of six lipids of the types that may be present in wool lubricants. Residual grease (fatty-matter extract from scoured wool) was also examined. It was found that,by developing a series of chromatograms with solvents differing in polarity, the lipids could be identified. Residual grease did not interfere with the resolution. [ABSTRACT FROM AUTHOR]