The process of hemp clothing production today is very similar to the process used millennia ago by the ancient world. Hemp fibre is produced from the plant called Cannabis sativa L. This plant grows to a height anywhere from 4-15 ft (1.2-4.5 m) and up to 0.75 in (2 cm) in diameter. The plant comprises an inner layer called the pith which is surrounded by a woody core, commonly referred to as hurds. Bast fibres form the final outer layer of the plant. It is this bast fibre layer which is used in the production of textiles such as hemp clothing. However, it should be noted that other parts of this plant do not go to waste. For example, the woody core has many uses as well such as in animal bedding, mulch, fuel and in building materials such as hemp concrete.
Production of hemp fibre for textiles starts in the field. The crop is ready for harvesting when the plants begin to shed pollen. From time of planting to harvest time generally only takes 70 – 90 days. At this stage, the crop is cut and the stalks are left in the field or in water to rett. Retting is a natural process which allows micro-organisms and moisture to break down the plant’s pectin. Pectin is a natural plant binder which helps keep the plant’s outer fibre layer connected with its inner woody layer. Retting the stalks and breaking down the pectin facilitates the separation of the fibres from the rest of the plant. An added bonus of this retting process which takes approximately 4 – 6 weeks is that it gives time for nutrients bound in the plant stalks and leaves to return back to the soil resulting in minimal need for fertilizer supplementation between hemp crops.
After retting, the hemp stalks must be dried to around 15% moisture content. This drying process can also take place in the field or inside a barn. Once the stalks are suitably dried, the process of separating the fibres from the rest of the plant can now begin. This process involves a series of increasingly fine combings of the fibres done in two stages known as scutching and heckling.
After scutching and heckling, the long, strong fibres are essentially ready for weaving although it will typically be put through a variety of softenings to make the fibre softer, less itchy and more flexible before it is then dyed and finally weaved into fabric for production of hemp clothing.There are some companies which use chemical means to remove the pectin binder and separate the fibres. This process uses harsh chemicals such as caustic soda which result in production of shorter and less durable hemp fibres. As such, you should know the origin and manufacture process used before you buy hemp clothing to ensure your clothing has been produced using the most environmentally friendly process which will also ensure greater durability and quality for you. A win, win situation!
Article From: Adrian Desbarats