Bamboo fiber is an environment-friendly natural fiber with excellent wearability and belongs to a new type of fiber. Bamboo fiber is to physically separate lignin, protein, fat and pectin from bamboo, and then extract bamboo fiber from it.
Bamboo fiber can retain the characteristics of bamboo to the greatest extent. It is a kind of green plant fiber, easy to wash and dry, cool in moisture absorption, stable in size, smooth to the touch, comfortable and breathable to wear, antibacterial and ultraviolet-proof. Today, with the emphasis on environmental protection and energy saving, the emergence of this new fiber can alleviate the gap problem caused by the increasing demand for natural fibers such as cotton in China to some extent.
Properties of bamboo fiber
1) Bamboo fiber has good length uniformity. The length can be made into cotton type, medium length type and wool type according to user's requirements;
2) Bamboo fiber has good thermal properties. Bamboo fiber begins to decompose at around 260℃ and ends at around 540℃. Its thermal stability is equivalent to ramie and superior to cotton fiber, flax fiber and bamboo pulp viscose fiber.
3) The initial modulus of bamboo fiber is lower than ramie fiber and higher than cotton fiber, which belongs to high strength and low elongation fiber and has high stiffness;
4) Bamboo fiber has low moisture regain, low water retention rate and good moisture permeability, so clothes made of bamboo fiber feel dry and comfortable;
5) Bamboo fiber has good antibacterial and bacteriostatic effect, which is higher than bamboo pulp fiber. In addition, because bamboo fiber contains sodium copper chlorophyllin, it also has good anti-ultraviolet effect;
6) The chemical properties of bamboo fiber are similar to those of other cellulose fibers. It is alkali-resistant and acid-resistant, soluble in strong inorganic acids, but relatively stable in general solvents. There are hydrophilic genes on bamboo fiber macromolecules, especially the morphological structure with cracks on bamboo fiber macromolecules, which has good dyeing performance.
Production technology of bamboo fiber
1. Pretreatment process
1) process flow: grey cloth inspection → seam turning → singeing → open width desizing → pickling → bleaching → mercerizing → drying.
2) Process formula and conditions:
The singeing is two straight lines and two reverse lines, and the speed is 90~ 100 m/min, ensuring the singeing smoothness to reach 3~4 grades.
Desizing bamboo fiber has more hairiness and heavy sizing. When desizing, a certain scouring agent should be added to strengthen flat washing.
Pickling Because the raw bamboo fiber is processed by physical methods, some bamboo skin often remains on the fiber, which affects the appearance quality of the cloth surface. The dilute acid treatment process can be increased.
The bleaching H2O2 is 4~5g/L, the PH value is about 10, and the time is 40min.
The mercerizing NaOH is 160g/L and the speed is 40m/min, which makes the fiber fully expand.
Drying is an additional process to ensure the consistency of drying and wetting of dyed semi-finished products. If the quality of mercerized products is better, this process can be omitted.
2. Dyeing process:
Process flow: Take long car dyeing with reactive dyes as an example. Pad dyeing reactive dye solution → infrared pre-drying → drying → pad dyeing solution and fixation solution → steaming → water washing → soaping → drying.
3. Finishing process:
1) technological process: softening → tentering → (pre-shrinking) → coding and packaging.
2) Process formula and conditions:
Softening agent 30g/l;
Shrinkage of pre-shrunk mercerized products can meet the requirements. If the customer requires a higher shrinkage rate, it must be pre-shrunk;
Pre-shrinking process and conditions: steam pressure 2.5kg/cm2, vehicle speed 30m/min.
Bamboo fiber is a kind of natural fiber with good wearability, and the dyeing process of natural fiber can be followed. Pickling and mercerizing processes should be well controlled. When the concentration is too high, the fiber strength decreases and the width shrinks too much, which is not conducive to subsequent processing. Bamboo fiber is rigid, so it should be dyed in open width, long rotation and winding. Rope processing is prohibited, otherwise it will cause dyeing defects (such as colored stripes and chicken paw prints). Practice has proved that the steaming method of reactive dyes is superior to the drying method. If special finishing is needed, such as enzyme washing and anti-wrinkle treatment, the dosage and time should be controlled. The technology of different varieties is different, but the technology is basically the same.