A fast, accurate and direct measurement of
cotton maturity and fineness
Cottonscope is a fully automated microscope that captures colour images of cotton snippets in water. Maturity ratio and fibre fineness is measured in 25 seconds. It combines the unique technologies of SiroMat and OFDA.
SiroMat is an automated version of the polarized light microscopy Standard Test Method (ASTM D1442-00) and was developed by CSIRO, Australia’s premier research organization. OFDA is the world’s leading image processing instrument for rapid, accurate measurement of animal fibres such as cashmere and wool. Over 300 OFDAs have been sold worldwide during the last 20 years.
The cotton fibre is a single biological cell which grows from a single seed. The outer primary wall grows in the first 15 to 20 days, after which a secondary wall fibre grows for another 25 to 40 days. This layered arrangement of the cellulose and noncellulosic walls gives it a birefringent property and utilising this property, we developed a patent pending optical setup.
Using our unique light setup, the inner cell wall illuminates with a red hue with an intensity proportional to the maturity of the fibre as shown in the image below.
The image shows fibres of similar widths, but the mature fibres are filled with a red hue and the immature fibre has a lack of colour and appears translucent. Samples are prepared, cut and weighed on a single module shown below.
The module contains a guillotine with a 0.7mm blade and a weighing station accurate to 1/1000th of a gram. The fineness measurement is performed at the same time as the maturity measurement.
Key benefits of Cottonscope
The current industry standard for cotton quality measurement is the Micronaire. However, its measurement results combines both maturity and fineness and cannot separate the two properties. This means that a coarse and immature fibre will give the same reading as a fine and mature fibre. Immature fibres:
are weaker, causing more breaks and shorter fibre length,
have more entanglements, causing neps and
take-up less dye, producing uneven colour in the final fabric.
Fineness is proportional to the cross sectional area of the fibre and is expressed in micrograms per meter. Finer fibres give a more even yarn and create fabric with a softer feel.