HEMP FIBERS

Hemp is one of the most valuable natural fibers, being known to humanity for millennia. Hemp fibers exhibit extraordinary properties: strength, durability, along with anti-bacterial and anti-fungal properties. The textile materials made traditionally of hemp fibers are very strong and durable (such as sails fabric or hemp denim), while being breathable and flexible,. The fibers can be used for ropes, twines and cords, which exhibit both strength and resistance to rotting or deterioration even in the sea water.  The major disadvantage of hemp in comparison to cotton (a disadvantage shared with flax) is that the traditional processing of these fibers (although complex, multistage and labor-consuming) results in a coarse, sturdy textile, while cotton can be much softer and more comfortable in garments.

Being able to produce soft, cotton-like textiles of hemp and flax is therefore the greatest challenge of the “green textile” trend. It is expected to allow manufacturing of fabrics with cotton-like quality and softness while being produced through organic cultivation: without the  excessive use of pesticides and fertilizers (necessary for cotton), and moreover - in a wider range of climatic conditions than those required for cotton, including colder climate regions such as in Canada. 

Hydrogen Link has developed a unique technology for natural fibers processing using our proprietary Catalytic Advanced Oxidation. The new technology is based on a treatment involving catalytic reactions with hydrogen peroxide H₂O₂. Hydrogen peroxide alone (although widely used in many bleaching and oxidative processes) is not capable of the efficient upgrading of bast fibers, which needs to involve thorough delignification and degumming, i.e. elimination of lignins, pectins, gums and hemicellulose from the bast (skin) of the plant.

However,  when combined with our proprietary catalyst, hydrogen peroxide H₂O₂ becomes a very powerful oxidative agent for the processing of various bio-materials, due to the formation of the super-oxidant molecules: hydroxyl radicals. With this technology, raw hemp or flax bast material can be processed into cotton-like, soft fibers, entirely surpassing the properties of traditionally-processed coarse hemp or flax. The key point of this process is to remove all “binding” and “filling” materials around the fibers from the stems -- lignins, hemicellulose, gums and pectins -- while leaving only pure cellulose in its natural form of thin cellulosic fibers or fibrils.

Cotton (which is currently the most widely used natural fiber) contains the highest amount of cellulose of all botanical fibers – close to 90%. Cotton does not need to be degummed but only cleaned, because of its natural "loose" formation in the cotton pods (bolls), which also host cotton seeds.  These bolls are ideal nesting sites for insects and pests and therefore cotton cultivation requires heavy usage of toxic pesticides and insecticides. It also needs large amounts of fertilizers and uses plenty of water. These requirements unfortunately make cotton one of the most polluting agricultural crop. The use of alternative natural fibers, such as hemp, flax, jute, kenaf, ramie etc.  represents an huge advantage towards cleaner and more resilient cultivation, since these plants are much more self-reliant. They can thrive without heavy support of chemicals in a relatively poor soil and in a wider range of climatic conditions.  However, while cotton fibers are made of almost pure cellulose and therefore are so uniquely soft and white in color, the bast fibers are incorporated in the structural parts of the plants:  in the skin of the stem.  Therefore, extraction and cleaning of these fibers from the plant tissue is much more difficult and involves many stages: "retting" - which is a biological process of softening and removing the lignins by bacteria, done by keeping the stems in the field of water ponds for weeks, followed by "decortication" - peeling the bast (skin) from the core of the stem, with subsequent "degumming" - performed most commonly by for example "alkali boiling" i.e. treating the fibers in harsh chemicals at high temperature until the lignins and gums are etched away.  Traditionally processed hemp still contains a significant amount of lignins and gums and  this is the reason why the currently available hemp and flax fibers are beige or creamy. When bleached to achieve whiter shades, they later undergo yellowing when exposed to light, especially UV. Therefore, it is essential to apply effective degumming and delignification of the fibers to achieve "cottonization" and not just bleaching (whitening of the lignins).

The quality of delignification process determines the quality of the hemp or flax fiber. However, another important aspect is that the processing does not use

The major environmental advantage of this process is that the reaction with hydrogen peroxide produces one single, harmless, by-product: water. No acids, caustic lye, ammonia, enzymes or solvents are used nor produced in the process. The treatment does not require elevated temperatures or pressures. Also, no significant investment in the equipment is needed for this process and it can be applied “in the field”, eliminating more than 20 traditional steps for hemp or flax processing, which normally take weeks form harvest to yarn.

Hydrogen Peroxide is the most environmentally friendly chemical of all, because it decomposes into water and oxygen, without any other byproducts being added by H₂O₂. In combination with our unique solid-state catalyst, it is able to fully upgrade - degum and cottonize all types of bast and leaf fibers. Our catalyst is heterogeneous (in a solid state) so it does not dissolve in the effluent, and it thus stays behind and can be reused. The process can be performed at neutral pH and at room temperature. It does not require expensive instrumentation such as stainless steel autoclaves needed to withstand the commonly used aggressive chemicals at high temperature and pressure.

Therefore - in terms of the environmental impact of the Natural Fibers processing - the Catalytic Advanced Oxidation with hydrogen peroxide is unique in its ZERO POLLUTION capability.

Upgrading of hemp with Catalytic Advanced Oxidation may be done starting from any form of the bast material - unretted or retted, peeled or decorticated, or even the whole stems directly from the field, without seasoning or retting.

Catalyzed Advanced Oxidation developed by Hydrogen Link allows processing  of the whole stems of hemp at room temperature and at neutral pH.

The result is clean hurd and fully cottonized, lignin-free hemp fiber.

Cottonized Hemp Fibers under Microscope

Processing of hemp by Catalytic Advanced Oxidation can be carried out upto the required softness vs. strength level. Single cellulosic strands of hemp can be achieved if needed.

FLAX  LINEN

Amongst the natural traditionall fibers, flax has been always valued for its textile qualities. Catalytic Advanced Oxidation (with Hydrogen Link Oxycatalyst combined with hydrogen prooxide) takes the degumming and cottonization of flax even further - towards full removal of lignins and gums and a clean whiteness.  All types of flax material can be fully processes - unretted or retted, peeled or mechanically decorticated. Moreover, all varieties of flax plant are suitable - textile or seed plants.