In the UK we use as much of our wool as possible and try to waste the minimum amount. To this end, the best and softest fibres are used for clothing, knitwear, knitting and weaving yarns. More coarse fibres are used in the production of carpet yarns. Any processing waste such as yarn ends or substandard fibre can be used in the production of felted underlay and insulation.
Before the fibre even gets to the processing stage it needs to be sorted. Once the fleece is shorn from the sheep the dags and substandard can be removed and the good fibre rolled ready to go on for other uses.
In some cases, the reject fibres are put into compost or on the garden (wool can work as a slug repellent due to its scales). As wool is able to absorb water and bio-degrades slowly it makes a good mulch, particularly for young trees and shrubs where it will also help prevent them being overcome by competition from weeds.
A project is being launched in Italy which is aimed at using all the fibres that aren’t suitable for processing for fertiliser. By subjecting the wool to hydrolysis, a chemical reaction takes place creating wool hydrolysate; essentially, the wool proteins is then in a form that can by spread onto fields for fertilising. This project is still under development, and more information can be found on the Life+GreenWoolF website.
In November last year we attended a conference in France to discuss the impact of wool scouring and produced this slide (see left) to illustrate our various waste streams. At The Natural Fibre Company, our waste streams are used as follows:
- Reject fibre: sold for processing into felt or insulation
- Card waste: some can be re-cycled into woollen spun yarns and some is sold as higher quality fibre for re-cycling
- Shoddy: this is dirty, short or poor fibre which has fallen out while carding and is either sold for felt and insulation or can be used for mulch or waste
- Hard waste: this is spun waste, whether singles or plied and at present this cannot be re-cycled, though some hard waste can be processed by garnetting into fibres long enough for spinning, and this is how yarns are made from re-cycled wool and silk, mainly in India
- Our scour effluent goes to the land as a fertiliser