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The dyeing principle and process of fleece fabric

  fleece fabric is favored by consumers because of its rich texture, smooth feel, good drape, noble, light and comfortable wear. But how do these wool fabrics, which are favored by consumers, translocation to us after dyeing? Today I'm going to talk to you about fleece fabric.

  Wool structure

  Wool is an elongated solid cylinder with a curly, rough surface, consisting of layers of scales, cortex, and medulla. The finer the wool, the more scales, because the scale layer is stretched outwards and protruding, increasing the friction between the fibers, resulting in mutual restraint and felting effect, and strengthening the holding force under hot and humid conditions. The cortex is composed of two parts, the normal cortex and the accessory cortex, which are the main components of wool and determine the physical, mechanical and chemical properties of wool fibers. The medullary layer is an opaque and loose material. The more medullary the wool, the flatter and rougher the shape, and the worse the quality.

  Finishing process of fleece fabric

  Due to the wide variety of wool fabric species, there are certain differences in finishing processes, such as smooth fabrics may involve: green repair → singeing → washing → cooking → dyeing → water absorption → drying - intermediate inspection → ripening → brushing → shearing → wet parking → decaying → voltage;

  The suede fabric involves: preparation → washing → dehydration → shrinkage → washing → dyeing → dehydration → drying → intermediate inspection → ripening → raising → brushing → steaming → steaming, so today we discuss the purpose and principle of the general finishing process.


  Objective: To remove vegetative impurities from wool.

  Principle: Use the difference in acid resistance between wool and cellulose impurities to remove impurities. Acid promotes the hydrolysis of cellulose impurities, makes it brittle, and is removed by rolling and washing. The -NH2 on wool adsorbed H+, began to absorb acid when pH=5, pH=1 reached saturation, no damage to wool. If the acid is continued to absorb, the wool main chain is hydrolyzed, so the acid concentration and temperature must be strictly controlled during the production process.

  Washing cloth

  Objective: To purify and improve hand feel.

  Boiling and steaming

  Objective: To make the fabric size stable, smooth surface, natural luster, soft feel, full of elasticity.

  Principle: When the wool fiber is spinning and weaving, it is subjected to uneven external force, so that there is internal stress in the fabric. Under wet and hot conditions, the internal stress is relaxed, resulting in uneven contraction. In the humid and hot treatment for a long time, a new cross-link is established in a new position to produce a styling effect.


  Objective: Woolen fabric under certain temperature conditions, after wetting agent, under the repeated action of mechanical external force, the fibers are entangled with each other, making the fabric shrink, increase the thickness, and produce a layer of fluff on the surface to cover the weave.

  Principle: The friction coefficient of the movement of wool against the scale (pointing to the tip of the hair) is larger than the friction number of the movement of the scale (pointing to the hair root), which is called the directional friction effect. When the shrinkage agent is present, the repeated random external force forces the wool to shrink and move along the scale, then the wool roots bite each other, and the fiber tip is free to cover the surface of the fabric, because the arrangement of the fiber is more chaotic, the result of the movement is to tighten.


  Objective: To reduce the shrinkage of woolen fabrics, to obtain dimensional stability and reduce pilling.

  Principle: By reducing the directional friction effect, improve the inherent elasticity of wool and limit the movement of wool between each other. The purpose of anti-felting is usually achieved by the deposition of fleece scales and polymers on the fabric surface.

  Each of the above finishing process needs to be carried out in the regular manufacturer, if a step is not in place, the fabric is easy to occur after the garment pilling, felting, deformation and other phenomena, especially after washing. Therefore, when consumers buy fleece fabric clothing, the formal brand with a certificate is the right choice.