Basic Characteristics Of Hemp Fiber

Discrete fiber characteristics

Except ramie fiber is long fiber.

They are all very short fibers. Therefore, in practice, the fibers are glued and grown longer by semi degumming process, and then used as a "monomer" to form yarn, in order to obtain low super high quality yarn.

This is the basic technology of other hemp fibers besides ramie.

If successfully implemented, flax can become a noble fiber material like cashmere and silk.

It is precisely because of this process that ramie textile technology can be made of refined cotton (full degumming) and linen (semi degumming) in flax and other textile processes.

Morphological characteristics of fiber cross-section

All phloem fibers are single celled, with slender shape, closed ends and cavity. Their wall thickness and length vary with varieties and maturity. The cross sections are elliptical or polygonal, with a layered radial structure. The orientation and crystallinity are higher than those of cotton fibers. Therefore, hemp fibers have high strength and small elongation.

Leaf fibers are irregular, porous cell bundles formed by single cell growth, and are not easily decomposed into single cells.

Fiber characteristics of high strength and low elongation type

Generally speaking, hemp fiber is a kind of

Its breaking strength is 5.0~7.0cN/dtex (cotton fiber is 2.6~4.5, silk is 3.0~3.5).

This is mainly due to the fact that bast fibers are mainly bast fibers, but phloem fibers are the basic skeleton of plants, and have higher crystallinity and orientation.

For example, flax has a crystallinity of 90% and a degree of orientation near 80%.

Because of its high crystallinity and orientation, the hemp fiber is the lowest fiber breaking rate for all fibers. In addition, this structural feature makes the hemp fiber obtain a very large initial modulus, 1.5~2.0 times higher than cotton fiber, 3 times higher than silk and 8~10 times higher than wool fiber, so the hemp fiber is relatively hard and not easy to deform, but at the same time, the hemp fiber becomes a very poor resilient fiber. Even if only 2% deformation, the elastic recovery rate is only 48%, while the elastic recovery rate of cotton fiber and wool fiber can reach 74% and 99% when the same size is deformed.

Pretreatment of raw linen before textile processing.

There are different ways of treating different hemp fibers from the original raw materials to the linen fibers that can be used for textile processing.

Pretreatment of ramie textile

The harvested ramie should be peeled and scraped first, and the skin of the ramie will be stripped off and scraped off the epidermis, and the dried linen will be dried to get the filamentous or flaky raw linen, that is, the commodity ramie, also known as raw hemp. The raw hemp must be degummed before spinning, and the adhesive between the fibers can be removed to meet the requirements of textile processing.

After degumming, the residual gum rate of ramie is below 2%, and its fiber is called leanma, which is white and rich in luster.

Pretreatment of linen before textile processing

Flax can not be spun by single fiber, and must be made into process fiber of bundle fiber. At the same time, flax stems are thin, and fiber from phloem can not be made by general stripping.

First, degumming must be made to separate cellulose substances from the phloem and the surrounding tissue components in order to obtain useful textile fibers.

There are two ways of degumming: the soaking method and the retting method. The former is degumming in a specific treatment solution while the latter is carried out under steam conditions.

At present, impregnation method is widely used in China.

After the impregnation and degumming, the flax must be dried first, then the wood part in the dried stems of the flax is crushed by using a crumb machine to separate it from the fibrous layer and to remove the hemp from the broken stem by using a flax machine.

In addition, there are also about 40% coarse textiles that can be used to remove fallen noil from the linen machine, called coarse linen.

The length, fineness and strength of linen are important parameters affecting the processing of flax yarns.

The length of linen is determined by the length of the linen.

The cultivation conditions and initial processing are generally 300~900mm; the linear density of linen is determined by the degree of fiber splitting, and the fiber sections made of linen are generally contained 10~20 single fiber.