Why Hemp?

Textile Properties
As the premier plant fiber, True Hemp or Cannabis sativa has served mankind for thousands of years. This venerable fiber has always been valued for its strength and durability. Materials made from hemp have been discovered in tombs dating back to 8,000 B.C.E. Christopher Columbus sailed to America on ships rigged with hemp. Hemp was grown extensively in colonial America by numerous farmers including George Washington and Thomas Jefferson. Betsy Ross sewed the first American flag from hemp. In fact, its combination of ruggedness and comfort were utilized by Levi Strauss as a lightweight duck canvas for the very first pair of jeans made in California.

For thousands of years hemp was traditionally used as an industrial fiber. Sailors relied upon hemp cordage for strength to hold their ships and sails, and the coarseness of the fiber made hemp useful for canvas, sailcloth, sacks, rope, and paper.

While hemp fiber was the first choice for industry, the coarseness of the fiber restricted hemp from apparel and most home uses. Hemp needed to be softened. Traditional methods to soften vegetable fibers used acids to remove lignin, a type of natural glue found in many plant fibers. While this method to remove lignin worked well with cotton or flax, it weakened the fibers of hemp and left them too unstable for use. Hemp therefore remained as an industrial fabric.

In the mid 1980's, researchers developed an enzymatic process to successfully remove lignin from the hemp fiber without compromising its strength. For the first time in history, de-gummed hemp fiber could be spun alone or with other fibers to produce textiles for apparel. This technological breakthrough has catapulted hemp to the forefront of modern textile design and fashion. Given hemp's superiority to other fibers, the benefits of this breakthrough are enormous.

Superior Properties
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 which is trapped in the fibers is warmed by the body, making hemp garments naturally warm in cooler weather.

Environmental Advantages
Hemp is an extremely fast growing crop, producing more fiber yield per acre than any other source. Hemp can produce 250% more fiber than cotton and 600% more fiber than flax using the same amount of land. The amount of land needed for obtaining equal yields of fiber place hemp at an advantage over other fibers.

Hemp grows best in warm tropical zones or in moderately cool, temperate climates, such as the United States. 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 Today
As a fabric, hemp provides all the warmth and softness of a natural textile but with a superior durability seldom found in other materials. Hemp is extremely versatile and can be used for countless products such as apparel, accessories, shoes, furniture, and home furnishings. Apparel made from hemp incorporates all the beneficial qualities and will likely last longer and withstand harsh conditions. Hemp blended with other fibers easily incorporates the desirable qualities of both textiles. The soft elasticity of cotton or the smooth texture of silk combined with the natural strength of hemp creates a whole new genre of fashion design.

The possibilities for hemp fabrics are immense. It is likely that they will eventually supersede cotton, linen, and polyester in numerous areas. With so many uses and the potential to be produced cheaply, hemp textiles are the wave of the future!

Checklist for Environmental Finishing of Textiles
The impact on the environment by the process of dyeing textiles vary greatly around the world. Many developing countries have no regulations regarding the methods of dyeing, the types of dyes used, and the disposal of waste. In the United States, and especially California, environmental laws regulate the types of dyes and dyeing methods used by commercial dye houses.

There is a lot of confusion regarding the dyeing of textiles and what is to be considered "environmental". When determining the measure of harm done to the environment by the dyeing process, one must take into account three elements:

1. The actual dye used and whether or not it has toxic properties.
2. The method of dyeing and how much energy is required.
3. How much dye gets into the fabric and the method of disposal of excess dye and chemicals.

Many people mistakenly believe that fabrics dyed using natural dyes will be less harmful to the ecosystem than conventional dyeing methods, but this is not always the case. The process of extracting pigment molecules from nature may require more energy and harmful chemicals than synthesizing them in the lab. In some dyes, the actual pigment molecules are the same, whether they originated in nature or the lab.

Dyes are molecules that absorb and reflect light at specific wavelengths to give our eyes the sense of color. With natural dyes, the molecules are extracted from natural substances such as plants, animals, or minerals. Synthetic dyes are produced in a laboratory and synthesized from other chemicals. Some synthetic dyes contain heavy metals and other elements that react negatively if released in the environment. Newer synthetic dyes tend to have less harmful elements.

The method of dyeing also plays a factor. Harmful chemicals may be added to the dye bath to help the dye molecules bind to the fibers of the fabric. Also the amount of energy used to run the dye machine in the form of mechanical action and heat vary greatly from region to region.

The handling of waste is probably the biggest factor to determine how detrimental the process is to the environment. Is the excess waste filtered and neutralized before it is put down a drain? Or is it just dumped into a river? Once again, environmental laws play an important role with developing countries usually using the cheapest and most convenient method of disposal.

The following methods of finishing textiles generally refer to modern methods used in industrial dye houses. We have listed which methods do not cause harm to the environment and are used by Hemp Traders to convert their fabrics.

Prepare for Dyeing

* No Chlorine bleached is used. Hydrogen Peroxide bleach is used on light or bright colors only.

* Enzymes are used to desize natural sizing. Sizing is a generic term for compounds applied to fabrics to improve their smoothness, abrasion resistance, stiffness, strength, weight, or luster. (Starch is generally used to achieve this effect.)

* Non-biodegradable synthetic sizing is reclaimed after the desizing process.

* Scouring (cleaning) agents used are biodegradable. No solvent scouring.

* No Mercerization, which is a treatment on fabric that swells the fibers of the yarns in a strong alkali. Piece goods, normally under tension, are immersed in sodium hydroxide (caustic soda) and then are neutralized in acid. This process causes a permanent swelling of the fiber which increases luster, strength and an affinity for dyes.

Dyeing
Low impact dyes or dye stuff is:

* Natural components are water soluble
* Fixation is 70% or more
* No heavy metal content

Low impact dye process follows these methods:

* Heat reclamation on site.
* Water filtration on site.
* No salt added to dye bath.

Additional auxiliaries and additives in the dye bath are biodegradable.

Finishing
The following mechanical finishes are acceptable:

Tentering: Process for holding a fabric to desired width during drying. A tenter frame machine holds the fabric firmly at the edges by pins or clips as it advances through a heated chamber. This is generally the final step in finishing, giving the fabric its finished appearance.

Sanforized: A trademarked control standard of shrinkage performance. A method of compressive shrinkage involving feeding the fabric between a stretched blanket and a heated shoe. When the blanket is allowed to retract, the cloth is physically forced to comply. Leaves fabrics with a residual shrinkage of not more than one percent.

Compacting: A permanent treatment by which heat and pressure shrink a fabric so that resulting texture is crepey/crinkled and bulky.
The following heat finishes are acceptable:

Calendering: Fabric is passed between heated cylinders under pressure to produce a flat, glossy, smooth, high luster surface.

Steam Chamber: Stabilizes the colors of dyes after printing and dyeing processes. Process where steam is passed through fabric. This partially shrinks and conditions the fabrics when applied, especially on wovens.

Heat Shrinkage: Improves shrinkage resistance and shape retention of fabric and often other desirable properties, such as wrinkle resistance by means of either dry or moist heat.

Singeing: Burning off protruding fibers from fabric by passing over flame or heated plates. Imparts the smooth surface necessary for printing and clear finishes.

The following aesthetic mechanical finishes are acceptable:

Brushing: Utilizes multiple brushes or other abrading elements to raise fiber ends thus producing a nap on surface of fabric.

Sanding/Sueding: Process by which fabric passes over rapidly revolving rollers covered with abrasive paper.

Napping: Raising the surface fibers of fabric by means of passage over rapidly revolving cylinders covered with metal points/fine wire brushes or teasel (plant) burrs.

The following chemical finishes are acceptable:

Enzyme Washing: The use of an enzyme (organic catalyst used to speed up a chemical reaction) to produce stone washed effects on fabrics. This process id less damaging to fabrics than actual stone washing and produces a highly desirable soft hand.

Biopolishing: Where cellulose (any group of enzymes that degrade cellulose) enzymes hydrolyze the fiber surfaces. This treatment improves hand, reduces fuzz and pilling and gives clearer finish. Biopolishing agents should adhere to the following requirements to be considered environmental.

* Softeners used are biodegradable.
* No Formaldehyde based resins.
* No undisclosed chemical finishes.
* No acid wash/No stone wash.

Source http://www.hemptraders.com