Plant fibre analysis

Fineness is one of the first indicators of how well a bast fibre will spin. For hemp as for flax, it depends on variety, harvest date, retting, scutching and refining treatments. Our laboratory measures it with the OFDA2000, the optical fibre diameter analyser used for animal fibres, following an in-house method derived from IWTO-47.

Choosing the fibre. Please select Hemp or Flax before adding to your cart: the price is the same. For a mixed order, add one line per fibre with the matching number of samples.

Each sample is opened and cleaned of woody particles (hemp or flax shives), then the fibre is cut into 10 cm staples laid on the grooved measuring slide of our sample preparer. The slide then passes under the instrument's microscope and camera, which measures the fibres automatically; results and histograms are shown on the screen of the computer connected to the instrument. You get a statistical measurement, free of operator bias, comparable from one batch to the next.

There is no international standard yet for hemp or flax diameter measured by OFDA. Our results describe technical fibre bundles as present in your sample, not elementary fibres. We do not measure length. Results are designed for comparison: fields, retting times, scutching settings, before and after refining.

The report includes

• sample identification (fibre, your references, variety, retting and preparation stage as declared);
• mean diameter (µm), standard deviation and coefficient of variation;
• number of fibres measured;
• diameter class distribution and histogram;
• from 2 samples, a batch summary with comparisons, at no extra cost;
• the laboratory comment, in the chosen language.

Sample: about 5 g of scutched, hackled or refined fibre per sample, as a clean sliver, as free of shives as possible. No whole straw.

Shipping: one sealed, numbered bag per sample, a sheet stating the fibre and your references (variety, field, harvest date, retting time, treatment), and the printed order.

Why these packing instructions?

• Paper envelope or bag: paper lets the sample adjust to the temperature and humidity of the testing room. The OFDA 2000 corrects for temperature and humidity, provided the fibres are at the same temperature and humidity as the room at the time of testing: this is what makes the results accurate.
• No staples: so nobody gets hurt when opening it.
• No tape: fibres would stick to the tape when opened.
• One labelled bag per sample: sample number, to avoid mix-ups.

Turnaround: 1 to 2 weeks after receipt.

Laboratory preparation: manual removal of shives and dust, 10 cm staples laid on the measuring slide, one slide measured per sample. No degumming or refining in the laboratory: we measure the fibre at the stage you send it.

Price: €5 per sample, hemp or flax.

Comparative summary: included at no extra cost from 2 samples in the same order, hemp and flax combined.

Options: several samples (quantity); return of samples (unticked by default).

Internal metrology control programme - in-house method derived from IWTO-47