Shive

The flax stem is built as a tube: an outer layer carrying the bast fibre bundles, wrapped around a woody xylem core. Retting dissolves the pectin cementing the two together but leaves both intact, and it is the mechanical work of scutching — breaking the straw between rollers, then beating it — that shatters the brittle core into short chips while the flexible fibre survives.

The mill then separates the two by weight and aerodynamics: the fibre is retained and the chips fall away. What is collected is a mix of woody fragments, some short fibre that came away with them, and dust. Screening sorts this into size fractions, and the fractions have different buyers — which is why shive is sold as a graded product rather than shovelled out as sweepings.

Animal bedding is the established outlet. Shive is highly absorbent, it is light, it composts well afterwards, and screened grades are low in dust — the last of these being the reason it commands a premium in horse bedding, where respiratory health is a real concern and dusty straw is a genuine problem. It is used for other housed livestock and small animals for the same reasons.

• Animal bedding — particularly for horses, where low dust is valued
• Particleboard and fibreboard furnish, as a wood substitute
• Biocomposites and bio-based building materials bound with lime or binders
• Horticultural growing media and mulches
• Industrial absorbents for oil and spill control
• Fuel, including briquetting for on-site heat

The panel and construction uses are the growth areas, and they rest on the same argument as bagasse in a cane mill: here is a lignocellulosic material, already collected, already broken to a useful size, sitting at one site in quantity. Where a panel plant or a biocomposite manufacturer is within economic haulage of a scutching mill, shive competes with wood chips on cost and on carbon.

Buyers specify particle size distribution — the fraction they want, screened out from the rest — along with dust content, residual fibre, moisture, and cleanliness. Residual fibre is a genuine nuisance in some applications: stringy fibre wraps around machinery in a bedding system and interferes with binders in a board furnish, so a well-cleaned shive is worth more than a fibre-contaminated one. For bedding, dust is the attribute that decides the sale.

The handling problem is bulk. Shive is very low in density, so a lorry loads out on volume long before it reaches its weight limit, and haulage economics restrict how far it can travel — which is why shive markets are regional and why compaction and baling matter more than the value per tonne would suggest. It is stored dry, since damp shive moulds and loses its bedding value, and it is dusty and combustible in a heap, so stores are managed with dust and fire in mind.