The James Hutton InstituteThis page is no longer updated. The Macaulay Land Use Research Institute joined forces with SCRI joined forces on 1 April 2011 to create The James Hutton Institute.
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The introduction of a fast but accurate and standardised method for measuring the fineness of ultrafine wool and speciality animal fibres (especially cashmere) has always been of vital interest of breeders, processors and fibre experts.
As part of an EU project (AIR3 CT94 0822), the OFDA has been proposed by the metrology group at DWI (German Wool Research Institute in Aachen) as a suitable method for measuring quality and yield of cashmere in raw fleeces. In the main time, the OFDA method has become a standard test method (IWTO-47-95) for measuring mean fibre diameter of sheep's wool fibre samples. The application of this standard is not expanded for cashmere yet, because there is still a lack of reproductive results of inter-laboratory round trials. There is also a lack of fine fibre samples as standards when using the OFDA for measuring such small diameter.
The objectives of this round trial are therefore to:
demonstrate the use of OFDA as a standard method for cashmere and mohair
show whether a standard within the cashmere fineness range (13-18 microns) in the calibration would exert influence on the results of the fineness measurement.
Twenty seven laboratories (research institutes and industrial companies) were invited to take part in the round trial. Four laboratories did not submit either their written agreement or measurements results to DWI, so that there are finally a total number of 23 participants: 21 laboratories from eight European countries, and also one from Australia and one from New Zealand. The participating laboratories were as follows:
Denmark
France
Germany
Great Britain
Italy
Portugal
Spain
Australia
New Zealand
Switzerland
Besides the OFDA method, four further methods have been applied for measuring the MFD:
The participating laboratories were asked to apply the whole range of measurement systems available to them. In practice, the laboratories have applied the following methods:
Cashmere:
Dehaired, washed, commercial samples. According to the cashmere supplier, the MFDs of the samples measured by using a projection microscope (IWTO-8), were as follows:
No 1 Chinese white 14.49 µm
No 2 Chinese brown 14.60 µm
No 3 Chinese white 14.94 µm
No 4 Afghan 15.89 µm
No 5 Iranian fawn 17.36 µm
Mohair:
Being used as old mohair top standards from the IMA (International Mohair Association), supplied by DWI:
No 6 27.3 µm
No 7 29.1 µm
No 8 34.5 µm
No 9 38.0 µm