Hemp Fibres
Botanical information
- Industrial hemp (Cannabis sativa ssp. sativa) and marijuana both belong to the Cannabis sativa family. However, industrial hemp contains low levels of the psychoactive compound THC (tetrahydrocannabinol) around 0.3% or less, which is responsible for the “high” associated with marijuana use.
- This low THC content allows hemp usage for various purposes without causing intoxication.
- Industrial hemp is a perennial dioecious plant.
Agroclimatic conditions
- Hemp plants can thrive in well-drained soil with a pH between 6.0pH and 7.0pH.
- Hemp prefers a mild climate with a humid atmosphere and a rainfall of at least 25 to 30 inches/year.
- It has a short cropping period and needs less pesticide and water to grow than cotton.
- Applications support the efficient use of all plant parts, including the roots and seeds.
- Bast fibres hold almost 20-30% of the stalk. The superior quality of fibres is obtained from the densely planted hemp fields.
- Though hemp is native to India and Persia, almost all the temperate and tropical zones cultivate it.
- Russia is the largest hemp fibre producer, accounting for 33% of annual worldwide production(2019).
- Countries such as France, Italy, Germany, Yugoslavia, Chile, Japan, China, and Peru produce a considerable quantity of hemp fibres annually.
Physical & Mechanical Properties
Length
5-55mm
Diameter
22-25 μm
Fineness
0.25-0.52 tex
Linear density[2]
3.0-2.2 tex
Moisture content
8%
Breaking elongation
3-4%
Chemical Composition
Cellulose
70-74%
Hemicellulose
15-20%
Lignin
3.7-5.7%
Pectin
0.8%
Wax
1.2-6.2%
Ash
0.8%
Table 1. Physical & mechanical properties and chemical composition of areca nut fibres
Features
- The hemp plant is ideal for organic farming as it does not require herbicides or chemical fertilizers. It nourishes the soil to retain nutrients and helps in retaining moisture.
- It also acts as a weed suppressor in the land and leaves the soil in excellent condition for any succeeding crop.
- It consists of a deep taproot system, allowing soil penetration, raising nutrients towards the surface and aerating the soil.
- Additionally, it does not drain the soil out of nutrients as the fallen leaves from this plant function as a rich organic matter for the soil.
- It is flammable and sensitive to UV, and microbial (fungus and bacteria) attack .
Uses
- Industrial hemp is a versatile resource for making rope, textiles, clothing, shoes, food, and paper.
- It is also used as acoustics for sound insulation or absorption .
- Also, it is used to create hemp-based bioplastics, insulation material, biofuel, composites, etc.
- The blends of hemp with other textile materials, such as cotton, nettle, etc., are introduced in the market, which is proving itself to be equally beneficial as other products.
- The users of hemp-based products include industries such as composites, textiles, automotive, fireboard, heat-insulating materials, and construction with fibre-reinforced concrete.
- It is also used in applications related to the reinforcements of these fibres in brake pad applications in the automotive industry.
- Research is underway for hemp fibre applications in sporting goods and musical instruments.
