Hemp: Excellent Performance To Achieve Ideal Fiber

In the past few years, we have made a thorough exploration of the functional properties of hemp fiber, and obtained a series of excellent properties with the support of a large number of experimental data.

In recent years, with the improvement of people's quality of life, the pursuit of green environmental protection and the trend of returning to innocence and fashion are rising day by day. Hemp as a green eco-friendly fiber, besides its natural antibacterial properties, UV shielding, moisture absorption, sweating, softness and comfort, skin care and cleanliness, odor absorption and wear resistance, it also has noble, elegant, simple, natural and practical style.

Therefore, hemp fabric has increasingly become the ideal material for advanced fashion designers.

Moisture absorption and quick drying are better than cotton fabrics.

The strength of hemp bundle fiber is significantly higher than that of cotton and linen, slightly lower than ramie, and elongation at break is basically the same as that of other hemp fibers.

The bending resistance of hemp fiber is between ramie and flax.

The resistance to torsion is comparable to that of other hemp fibers.

Hemp fiber has a single fiber length of 15~25 mm, fineness of 15~30 microns, fineness is only 1/3 of ramie, close to cotton fiber.

Because hemp single fiber is shorter, textile fibers are usually used in processing, that is, 3~10 fibers and are used as spinning fibers, weaving, dyeing and printing together. In this way, although the process fibers are more rigid than cotton fibers, the fibers become more and more soft and comfortable when processing and using.

It can be clearly seen from the SEM that the ends of hemp fibers are round and arc rather than prickle, so that even if the fiber is thicker, there will be no prickle sensation of ramie.

After degumming, the degree of polymerization of hemp fibers is small (about 70% of linen, half of cotton, 1/8 of ramie), and the cavity of the fiber is large (about 1/3~1/2 of the cross-sectional area, much larger than that of ramie, flax and cotton).

Therefore, hemp fiber has excellent moisture absorption and breathability.

Taking hemp cloth as an example, its moisture absorption rate is 7.43mg/min, and its moisture dissipation rate is higher than 12.6mg/min. Hemp cloth has 27% higher moisture absorption rate and 32% moisture dissipation rate.

In the dry season of spring and autumn, the hemp fiber has good thermal insulation, and it is cool and pleasant in summer.

On the one hand, the hydrophilic genes in hemp fiber molecules are easy to combine with water molecules and adsorb water molecules. Their loose molecular structure and hollow shape can not only increase the thickness of air layer, but also fill capillary condensate water in large quantities, making the hemp fiber hygroscopic more fast. On the other hand, the cracks and holes on the surface of hemp fibers are favorable for wet dissipation.

Therefore, hemp fiber is very suitable for all kinds of clothing raw materials.

The results showed that the moisture regain of hemp fiber was basically the same as that of cotton fiber under the same environmental conditions. The standard moisture regain of hemp fiber was 7.9%~9.7%, cotton fiber was 7%~8%, hemp fiber was slightly higher than cotton fiber.

Under the humidity of 65%, the moisture absorption and desorption rate of hemp fiber is obviously higher than that of cotton fiber.

Using the same specification hemp fabric and cotton fabric, the humidity control box and electronic balance were used to absorb moisture at 100 degrees C and dry test at 105 degree temperature. From the test results, we can see that the moisture absorption and drying rate of hemp fabric is obviously higher than that of cotton fabric.

Providing a protective barrier for human health

Hemp fiber has excellent antibacterial and deodorant properties, which is related to its molecular composition and morphology.

Hemp fibers have porous structure and strong adsorption properties. Under natural conditions, hemp fibers will absorb more oxygen, which will destroy the living environment of anaerobic bacteria, which makes the hemp structure have an antibacterial advantage in structure.

At the same time, the fabric made of hemp fiber can quickly discharge sweat from human body, thereby destroying the humid environment where bacteria live and showing antibacterial properties.

In addition, hemp plants contain a variety of active phenols (four hemphenoxin THC, hemp two phenols CBD, hemphenoxin CBN), organic acids (oleanolic acid, ursolic acid, sixteen alkanic acid) and inorganic salts (NaCl). These substances have obvious killing and inhibiting effects on many kinds of bacteria.

According to the AATCC qualitative bacteriostasis method, the diameter of the bacteriostatic rings of different hemp fabrics for different microorganisms is: Staphylococcus aureus 9.lmm, Pseudomonas aeruginosa 7.6mm, Escherichia coli 10mm, Candida albicans 6.3mm, according to the qualitative bacteriostasis method of Military Medical Science Academy of the PLA.

At the same time, it has obvious killing and inhibiting effects on Trichophyton plaster, Penicillium and Aspergillus.

According to domestic and foreign tests, the natural inhibition rate of hemp fiber to Staphylococcus aureus, Escherichia coli and Candida albicans was over 99%, and the washing time was 50 times.

After testing, hemp fiber products also have good mildew resistance and mite resistance.

The hemp fiber blended towel was tested by AATCC30-2004 in the United States. It had no Aspergillus niger growth for 7 days at 20 degrees centigrade, and had good mildew proof effect.

The protective performance of bedding made from hemp fiber to dust mites reached 67.07%.

Therefore, hemp fiber products can give consumers a healthy protective screen.

Hemp fiber can not only develop textile products, but also develop home textile products. The market potential is huge.

Excellent anti radiation and adsorption properties.

Hemp fiber has excellent UV radiation resistance.

One hemp fiber has a certain lignin content after degumming, which is not found in cotton fibers. Lignin is a natural ultraviolet absorber.

Secondly, the hemp fibers are irregular triangular, quadrilateral, hexagonal, oblate, round or polygonal, and the middle cavity is linear or oval.

From the molecular structure analysis of hemp fiber, its molecular structure is spiral, multi prismatic and loose.

After the light wave or sound wave is injected, the light wave and acoustic wave form diffuse reflection and multilayer light refraction in the crystalline area of hemp fiber, and are destroyed and absorbed in the amorphous regions, gaps and holes of the fiber molecules, causing the hemp fabric to have a good function of preventing ultraviolet radiation.

The Institute of physics of the Chinese Academy of Sciences tested that ordinary clothing can only block ultraviolet rays of 30%~90%, while ordinary hemp fabrics do not need special finishing, which can shield more than 95% of ultraviolet rays. Hemp canvas and other 100% can resist ultraviolet radiation.

Hemp fiber is a natural fiber. The cellulose content of hemp fibers used in clothing is usually greater than 95%. Therefore, the antistatic properties of hemp fibers are similar to those of cotton fibers.

Hemp fibers have excellent adsorption properties.

By comparing the adsorption properties with cotton fibers, the results showed that the adsorption capacity of hemp fiber was stronger than that of cotton fiber under the same conditions.

This is related to the structure of single fiber. The porous structure of hemp fiber increases the adsorption area and improves the adsorption performance.

From the analysis of the structure and morphology of hemp fiber, it is found that hemp fiber is porous and hollow, and its cross-sectional shape is extremely irregular. This multi longitudinal crack and irregular shape give the hemp a larger adsorption area, thereby exhibiting excellent adsorption properties.

In addition, hemp fiber contains trace chemicals, which can react with the chemical components of total volatile organic compounds (TVOC), thereby enhancing the adsorption capacity of TVOC.

(China textile daily)