Hemp Seed Fiber

Fiber Hemp and Hemp Fibers, the Fiber Plant Hemp for Hemp Textile

Hemp for fibers makes ecological sense

Hemp (Cannabis sativa) is cultivated – mainly in Europe and worldwide, traditionally and currently – for the production of fibers. Fiber hemp varieties are now available for this purpose. Side effects are low THC levels and high CBD levels. Hemp fibers are versatile and make everything – from the finest cloths to modern materials and plastics. From an ecological point of view, fiber hemp can score points in various industries: for example, in the construction of buildings, in the plastics, textile and paper industries, as well as in agriculture.

The fast-growing plant is a good cropping member in the field and leaves a bottom of the soil [1]. Due to the dense, high growth, weeds are suppressed, which is why hemp can be grown without herbicides. Plant protection measures against insects or fungal diseases are also not required. Hemp is insensitive, also because it is not related to other crops (except hops).

Hemp fibers – cultivation and harvest

The planned use of hemp fibers determines the cultivation measures in the field. Seed starch in fiber hemp affects fiber quality. The denser the stock, the higher the stalk content and the finer the fiber becomes. The yield of hemp seed is getting smaller.

To obtain the highest fiber qualities, the so-called long fibers used for high-quality textiles, hemp is harvested and processed by hand in Romania or China. This includes the traditional, very labor-intensive water roasting [2].

Hemp for fiber useIn industrial nations, hemp's harvesting and processing technology has not been developed for 50 years and is today a technical challenge. After decades of ban today mowers for straw harvesting and combine harvester for the straw and seed harvest in use. These leave a short straw of hemp straw for the so-called field toasts [3]. Because of the toughness of the hemp fibers, high losses of 40 to 50% occur during machine harvesting. Nevertheless, straw yields of 4 to 10 tonnes per hectare are achieved. The hemp straw allows a fiber yield of 30 to 40%. In addition, the wood core of the hemp stick falls in the form of the so-called shives, for which there are also technical exploitations.

fiber quality

Hemp stalks in the roast

Hemp fibers are particularly long, tear-resistant and resistant. They run in the direction of the stem, are arranged in a ring around the stem and support the 2 to 4 m tall plant. They mainly consist of cellulose and hemicellulose. Hemp fibers are similar in structure to cotton fibers.

Unlike cotton, however, the fibers in the hemp stems must first be digested. A first step is the so-called roasting. In the case of traditional water roasting [2] (right), you get the valuable long fibers and the tow. Tow is a mixture of short fibers and shives.

In technical processing chains such as field roasting [3], only short fibers of varying quality and shives are produced.

Long and short fibers of hemp are among the most tear-resistant natural fibers. This makes them interesting as a substitute for glass fibers. The fiber fineness is important on the one hand for good insulating and insulating effect in building and on the other for further processing into yarns. The long fibers of hemp are qualitatively comparable to the best Maco cotton and have a natural shine. They are made from them garments with high wearing comfort. Hemp shirts and hemp jeans are cool on the skin, hypoallergenic and very hard-wearing.

Hemp Fibers for all Purposes

Hemp fibers were indispensable for many important products in the emerging nations of the world until just a few decades ago. You wrote history. Currently they are used for specialty papers from the finest filter paper to banknotes to the most beautiful handmade paper, for textiles from fashionable shirts or blouses to comfortable trousers to rustic bags as well as for novel materials. For the different product lines different fiber qualities are needed as raw material and appropriate processing steps are applied.

Multifunctional Natural Fiber

Nonwovens are non-woven, yet flat, coherent fibers, similar to felt. Depending on the initial quality of the hemp fibers, nonwovens with different suitabilities are obtained. Thanks to their environmental friendliness, they can be used, for example, for plant cultivation or for mulching mats. They are also popular for small cages in animal husbandry, because they are absorbent, as well as edible and digestible. Because of their durability and toughness, they are also suitable as anti-erosion mats on embankments or as greening fleeces that already contain seeds.

Materials for the automotive industry

High-quality natural fiber fleeces are being used increasingly and successfully in the European automotive industry. One manufactures molded parts with very good accident behavior from hemp fiber webs. This new technique is competitive.

However, not only natural fiber reinforced plastics can be made from hemp, but also other types of thermoplastics and composites suitable for injection molding and extrusion processes. Like car interiors, window frames, musical instruments, furniture and toys can be produced in an environmentally friendly, durable, lightweight and durable wood look. Likewise, components for building materials and insulation from hemp fibers can be produced. These improve the technical parameters, life cycle assessment and occupational safety by replacing glass fibers, asbestos and mineral wool.

But that's not all – farsighted engineers and scientists have long been working on composite materials that consist exclusively of natural fibers and biopolymers instead of synthetic resins, so that these novel materials would not only be recyclable, but also compostable. The balanced CO2 balance also makes them ecologically valuable.

Hemp paper preserves primeval forests

Hemp fibers, unlike wood fibers, contain very little lignin. This has the advantage that it does not have to be removed chemically for papermaking. The paper consumption in Germany is extremely high. At more than 200 kg per person per year, it is well above the average of the industrialized nations and many times higher than the consumption of developing countries, whose inhabitants consume an average of 18 kg of paper per year. For the production of white fresh fiber paper pulp [4] is consumed, which is usually obtained from wood using large amounts of energy and water. Paper eats forests worldwide: from tropical rainforests to Scandinavian, Russian and Canadian virgin forests.

That was not always so. Until 120 years ago, practically all paper in Europe was made of rags and these, like all cloths and ropes, consisted almost entirely of hemp or flax. The noble papers for the book printing and the canvas for oil paintings (English canvas) mostly came from the shiny, resistant fibers of hemp. Hemp paper has a millennia-old tradition dating back to ancient China. It is particularly light even without chlorine bleaching, as hemp fibers are very light. Hemp paper is still particularly opaque. Hemp paper was then and is now more expensive than wood paper, it is more resistant, less yellow, is water and tear resistant and to process different strengths and qualities. Ecologically of interest is today, in addition to the production of high-quality special papers from the valuable fibers, and the production of cheap paper and cardboard from the shives that used to be burned.

Hemp shives – from waste product to renewable resource

The hemp stem consists of 30 to 40% of fibers and 50 to 60% of shives (or tow). Shives consist of 35% cellulose, 18% hemicellulose and 20% lignin. They are very absorbent and are therefore very good as easily compostable animal litter. However, because of their high elasticity and porosity, they are also used for impact and thermal insulation, for floors and lightweight building blocks or breathable insulating plasters in low-energy buildings. There is even more utilization for the former waste product: pulp production for paper as well as construction and chipboard from biological binders and natural fibers.

With hemp, the quantities of different products – fibers, oil and shives – are so large that the harvesting and utilization of each of the components can be of decisive importance for the economy and thus the ability to grow.

The Future of Hemp

Like all properties of hemp, its fiber quality is mainly influenced by variety, cultivation, harvest and digestion methods. Breeding of improved fiber hemp varieties and growing trials to optimize yields and machinery, as well as the provision of seeds, are tasks of the agricultural sector.

Procedures for producing defined fiber grades that meet Indus- trial requirements must be developed and put into practice. In order to be able to use hemp fibers for textile and technical applications more frequently, however, it also requires valid quality and test standards as for other fibers.

In the ecologically and economically highly interesting plant hemp, half a century of complete standstill has to be made up.

 

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