John Horsfield processes hemp so that it can be used in mattresses, animal bedding, as a building material and a biofuel.
“Hemp is the strongest grown natural fibre and it does not stretch,” says John Horsfield, a hemp processing supervisor at a farm in North Yorkshire. “It can be used for all sorts. We use it for mattresses, animal bedding, as a building material and a biofuel.”
Some farmers grow hemp for cannabis oil, which can be bought legally in high street shops, but the hemp Mr Horsfield deals with is used as a fibre product.
Hemp is derived from the cannabis plant but this contains almost no THC (tetrahydrocannabinol) – the active ingredient that makes cannabis a drug – which is all contained in the leafy part of the plant. Hemp instead consists of the fibre and stem of the plant and is thought to be the first domestically cultivated plant, dating back thousands of years.
Mr Horsfield started working at the hemp plant, owned by mattress manufacturer Harrison Spinks, nine years ago and became supervisor in charge of the plant last year. Before, he worked in sales and was a stay-at-home dad. He came across the hemp job when he was looking for something that would allow him time to pick up his children from school. Some of the hemp he processes comes from the farm, but he also works with other local farmers and is on the lookout for more to grow the plant. “This year, we are growing 95 acres of hemp, and a total of 245 acres in partnership with other farmers.”
The processing starts in the fields, when the hemp is harvested. “We let it ret before we bale. Retting involves wetting the hemp and then letting it dry out, which helps it to break down. The process can take four to six weeks, depending on the weather. This process must take place before it is processed otherwise the fibres are too strong and would break the machinery. The hemp then comes into the factory and we open the bales with a shredder. We separate the outer fibres from the inner wood (which we call shiv), using different machines to separate the wood from the fibre and to clean and open the fibres.”
The process is noisy and there is a lot of dust, so the workers wear protective gear and have yearly health checks.
Due to hemp’s coarse and strong structure it is ideal for applications such as rope, canvas and paper. New methods of breeding and processing the plant mean a finer, softer fibre can be produced.
Hemp can also be used to replace oil-based materials such as nylon and polyester. “It helps us stop using fossil fuel-based carbon materials, as well as actually locking up atmospheric carbon in our product,” says Mr Horsfield. “It absorbs huge amounts of carbon as it grows, and when you use it you lock this carbon up. The best thing about the job is knowing we are actively removing carbon from the atmosphere. Hemp has the potential to be a huge tool in the fight against climate change.
“One of the most exciting uses is as a building material. You can make hempcrete (hemp concrete), which is a natural product and a great insulator. It regulates humidity and locks up carbon. Modern concrete is responsible for nearly 10 per cent of the world’s energy use in its manufacture alone, so hemp is a much greener alternative.”