Fibre soft and slender substance with length to diameter ratio at least 10:1,  the cross-sectional area less than 0.05mm2. For textile fibers, the ratio of length to diameter is generally greater than 1000:1. 

About textile fibers: Natural fiber, such as cotton, hemp, wool, silk and so on; Chemical fiber refers to natural or synthetic polymers as raw materials, through chemical methods and mechanical processing made as fiber.

 

1) According to the source of raw material: Regenerated fibre and Synthetic fibres

  • Regenerated fibre also be called as synthetic fiber, using natural polymers or lost textile processing value of fiber raw materials through a series of chemical treatment and mechanical processing be fiber again, the chemical composition of the fiber and original polymer is alomost same. Including Regenerated cellulose fibre (such as viscose fiber, copper ammonia fiber), Regenerated protein fiber  (such as soy protein fiber, peanut protein fiber), regenerated inorganic fiber (such as glass fiber, metal fiber)  and regenerated organic fiber (such as chitin fiber, seaweed gum fiber).
  • Synthetic fiber is made of natural low molecular compounds such as petroleum, coal, limestone, natural gas, salt, air, water and some agricultural and sideline products as raw materials, through chemical synthesis and processing be fibers. There are seven common types of synthetic fibers: polyester fiber (polyester), polyamide fiber (nylon), polyacrylonitrile fiber (acrylic fiber), polyvinyl formaldehyde fiber (vinylon), polypropylene fiber (polypropylene), polyvinyl chloride fiber (chlorinated fiber) and polyurethane elastic fiber (spandex), etc. 

     

     

    2) Classification by morphological structure: Continuous filament and Staple fibre

    • Continuous filament 

      During chemical fiber manufacturing process, spinning fluid (fusant or melt) after spinning forming and post-processing, the length of fiber is caiculated in kilometers is called chemical fiber filament. Chemical fiber filaments can be divided into monofil, multifilaments, twisted fibers, double twisted fibers, cord fibers and Textured filament.

      Monofilament: A single continuous fiber of very long length.

      Multifilaments: A filament composed of two or more single filaments joined together. Complex filaments of chemical fibers are generally composed of 8 to 100 single fibers.

      Twist yarn: twist Multifilaments  becomes twist yarn.

      Double twist yarn: Two or more strands of twist yarn are combined to be double twist yarn.

      Cord wire: composed of more than one hundred to several hundred single fibers, used to make tire cord fabric.

      Textured filament yarn: The chemical fiber filament is deformed and processed so that it has the appearance characteristics of curling, spiral, ring and so on, showing fluffy and flexible filament.

      • Staple fibre

        The product of the chemical fiber is cut into few centimeters to dozen centimeters in length, it is called staple fiber. According to the different cut length, staple fibers can be divided into cotton type, wool type and medium long staple fibers.

        The length of Cotton type fibre is 30 ~ 40mm, the linear density is about 1.67dtex, the fiber is fine, similar to cotton. The length of Wool type fibre is 70 ~ 150mm, the linear density is 3.3 ~ 7.7dtex, the fiber is thicker, similar to wool; Mid fibre has a length of 51 ~ 65mm and a linear density of 2.2 ~ 3.3dtex, between cotton type and wool type.

         

        3)  Classification by fiber manufacturing method

        Chemical fibers can be divided into two categories according to the basic manufacturing methods,  melt spinning fibers and solution spinning fibers (i.e. dry spinning fibers and wet spinning fibers).

        • Melt spinning is polymer melt is pressed out of the spinneret hole, melt is solidified into silk in the surrounding air (or water).
        • Dry-spinning is polymer concentrated solution is pressed out from the spinneret hole form as trickle, solvent evaporates rapidly in hot medium and solidifies into silk. 
        • Wet spinning is polymer concentrated solution is pressed out of the spinneret hole and solidified into silk in a coagulation bath.

           

          4) Classification by composition within a single fiber

          • Single-component fibers: Fibers composed of the same polymer are called single-component fibers, and most conventional fibers are single-component fibers, such as polyester.
          • Multicomponent fibers:Fibers composed of two or more polymers are called multicomponent fibers, such as acrylic fibers. 
          • Composite fiber:the components are arranged regularly along the fiber axis and form a continuous interface fiber.
          • Blended fiber: components are randomly dispersed or more evenly mixed fiber

             

            5) Classification by fiber difference