Hemp fiber is composed of cellulose, pectin, and waxes. Pectin is found in the middle lamella of the cells. It glues the elementary fibers to form bundles. Lignin encrusts the cellulose and contributes to the hardness and breakability of the fibers. The content of additional substances (other than cellulose) in hemp fiber is much higher in hemp than in cotton. This means that hemp requires different processing. The higher the cellulose content of hemp fiber, the better quality the fiber will be. Understanding the physical properties of fiber can help us to understand its benefits in a range of different applications. In this section of this article, therefore, we will take a brief look at some of the key properties and characteristics of this bast fiber.
Hemp promises to be the magical crop that can satiate the human needs for clothing, nutrition, packaging, and even housing; without hurting the sustenance of our planet. Hemp fabric is a sustainable textile made of fibers of a very high-yielding crop in the cannabis Sativa plant family. Historically used for industrial purposes, like rope and sails, hemp is known as one of the most versatile and durable natural fibers. Hemp fabric is deliciously soft on the skin and is known for growing softer with each wear. Hemp is naturally resistant to bacteria and provides natural UV protection. That means it protects your skin and retains color better than other fabrics. As you can see, hemp fabric is quite practical. It literally prevents you from getting stinky, gets softer with more use, and is stronger and longer-lasting than cotton.
Can hemp be the future?
Hemp fiber or industrial hemp is obtained from the outer layer or the bast of the Cannabis sativa plant, which is more popular for producing marijuana or hashish. However, while marijuana contains 20 percent tetrahydrocannabinol content (THC) which causes the high when smoked, industrial hemp only contains 1 percent THC. This fiber has some incredible properties: it conducts heat, dyes well, resists mildew, blocks ultraviolet light, and has natural anti-bacterial properties. It is used in many industries including paper, biodegradable plastic, construction, health food, chemical clean-ups, and fuel. Automobile companies like BMW use hemp fiber to reinforce their door panels for better safety standards. There’s even an urban legend that claims the first pair of Levis jeans were made from hemp!
Today it is similar to linen and can be used to make anything that is made out of cotton. The fabric is porous and thus retains color and is very breathable. Hemp clothing is highly durable and does not lose its shape easily. The fact that it is anti-bacterial and blocks ultraviolet rays doesn’t hurt. Turning to hemp clothing is a big step you can take as a conscious consumer and will go a long way in saving our planet’s resources.
Mechanical Properties of Hemp
Throughout history, hemp has been prized for its strength and hard-wearing properties. Naturally, the fiber is strong and sturdy, without much stretch. In all-natural cellulose fibers, the molecules are highly oriented parallel to one another in fibrils, but they spiral around the fiber, thus reducing the degree of orientation parallel to the fiber axis. In hemp and other bast fibers, the spiral angle is small, less than 6°, so that these fibers are highly oriented and give high strength and low extensibility (6). The tenacity (N/Tex) of hemp fiber is 0.47. The tensile strength of the single hemp fiber is in the range of 340–527 Mpa (7). However, hemp fibers can vary considerably in tensile strength and other mechanical properties due to the variability in growing conditions and other factors. Different varieties of hemp also differ considerably in these regards. Retting period length and other processing factors also play a role in determining the average fiber strength and characteristic strength of hemp fibers.
Hemp fiber is one of the strongest and most durable of all natural textile fibers. Products made from hemp will outlast their competition by many years. Not only is hemp strong, but it also holds its shape, stretching less than any other natural fiber. This prevents hemp garments from stretching out or becoming distorted with use. Hemp may be known for its durability, but its comfort and style are second to none.
The more hemp is used, the softer it gets. Hemp doesn’t wear out, it wears in. Hemp is also naturally resistant to mold and ultraviolet light. Due to the porous nature of the fiber, hemp is more water-absorbent and will dye and retain its color better than any fabric including cotton. This porous nature allows hemp to “breathe,” so that it is cool in warm weather. Furthermore, air that is trapped in the fibers is warmed by the body, making hemp garments naturally warm in cooler weather.
Hemp is an extremely fast-growing crop, producing more fiber yield per acre than any other source. The amount of land needed for obtaining equal yields of fiber places hemp at an advantage over other fibers.
Hemp grows best in warm tropical zones or in moderately cool, temperate climates.
Hemp leaves the soil in excellent condition for any succeeding crop, especially when weeds may otherwise be troublesome.
Where the ground permits, hemp’s strong roots descend for three feet or more.
The roots anchor and protect the soil from runoff, building and preserving topsoil and subsoil structures similar to those of forests.
Moreover, hemp does not exhaust the soil.
Hemp plants shed their leaves all through the growing season; adding rich organic matter to the topsoil and helping it retain moisture.
Farmers have reported excellent hemp growth on land that had been cultivated steadily for nearly 100 years.
Hemp can produce 250% more fiber than cotton and 600% more fiber than flax using the same amount of land.
Hemp uses about 5% of the amount of water it takes to grow cotton and can often be rain-fed.
Hemp grows densely as well, leaving no room for weeds and competing plants, and is less vulnerable to insects, which means little to no use of pesticides.