Basic knowledge of printing and dyeing finishing
Finishing refers to the treatment of fabrics before and after dyeing The finishing process of cloth surface, specifications, feel, velvet, etc.
At present, the finishing department of our factory is divided into three major departments: Whole Factory A; Whole Factory B; Special Wholesale Factory.
The main production machinery includes: shaping machine; pre-shrinking machine; catching machine; sanding machine; brushing machine; shearing machine; drying machine; washing and degreasing machine; steam engine.
Definition of a certain stereotype
(1) Definition: in stereotypes At a certain temperature of the machine, some machinery and additives are used to produce various physical or chemical reactions to remove the internal stress of the fibers in the fabric, stabilize the fabric at a certain size, and achieve reasonable specifications (sealing degree, gram weight, shrinkage, twist, etc.) and improve the flatness and feel of the cloth surface.
In simple terms:
1. Control specifications (sealing degree, weight)
2. Control shrinkage (horizontally, vertically) and twist
3. Improve hand feel
4. Adjust fabric Pattern
5. Special styling
*Special processing that needs to be done in the styling department is as follows: waterproof, odor-proof, anti-bacterial, Anti-stain, anti-wrinkle, anti-static, anti-infrared, anti-UV, fragrance, aloe vera, cool treatment, quick-drying
(2) Type:
A Reversible styling: After the cloth is shaped and washed, it can basically return to its pre-washed state, for example: cotton cloth is normally shaped.
B Irreversible shaping: After the cloth is shaped and washed, it cannot return to the washed state before shaping, such as: gray cloth shaping, resin shaping, etc. (Embryostomy is a type of thermostable setting)
(3) Temperature of setting
A Cotton-colored cloth: usually set at 150℃
B Cotton bleaching: usually set at 140℃ (to prevent yellowing)
C T/C, CVC, etc. contain POLY ingredients, nylon ingredients: light color 130℃, dark medium color 110℃ or less to set (avoid washing fastness is not OK)
D Artificial hair: usually set at 110°C (thermoplastic setting)
E Gray cloth set: usually set at 190°C
F Resin shaping: usually 170℃ The temperature setting expression methods are different.
(4) How to control the specifications of the setting machine
1. Working principle of the setting machine
Cloth guide system —- padding system —- overfeeding system —- tenter system – —Drying room and heating system—-cloth discharging system
During the processing before setting, the fabric is subjected to many mechanical effects, which often causes the fabric to stretch in the warp direction. , shrinkage in the weft direction, uneven cloth sealing and varying degrees of weft skew. Using a tenter setting machine for finishing can make the fabric specifications uniform and stable. The fabric has a certain degree of plasticity under hot and humid conditions, The setting machine makes the irregular fabric more regular after being moistened, stretched and stretched, and then adjusted in the vertical and transverse directions by the overfeeding system and the tenter system. Under the certain thermal action of the hot air, the fabric becomes more regular. The required specifications.
The overfeeding device can make the fabric feeding speed greater than the needle chain operating speed, so that the fabric will not be stretched in the warp direction, but will shrink the fabric. The rate is reduced. Stenter setting is to use mechanical action to stretch the fabric to a specified size under the wet and hot state of the fabric, eliminate part of the internal stress, and adjust the state of the warp and weft yarns in the fabric, thereby obtaining temporary setting.
2. The evolution of specifications on the setting machine
Pre-setting specifications — -Stretch adjustment, overfeed adjustment, needle holder adjustment, temperature setting and hot air setting, machine setting, fabric tension adjustment—-final specifications
Explanation of two terms
A Sealing: There are practical sealing and edge-to-edge sealing, which refers to the width of the cloth. .
B Weight: How many grams per square meter of fabric
C Shrinkage: When the fabric of unit size is washed and dried, The ratio of the final size to the original size. Generally, the shrinkage value is a negative shrinkage value, but positive shrinkage values may also occur. Shrinkage is divided into horizontal shrinkage and vertical shrinkage. Ready-made garments require horizontal and even straight shrinkage. Generally, the shrinkage of predetermined fabrics is small and stable. Adding resin can improve the shrinkage of sample fabrics.
D Grain slope: The texture is related to the yarn twist, origin, fiber length, weaving method, etc. The slope of the fabric grain directly affects the appearance of the garment.
E Torsion (twist): the change in the slope of the cloth grain before and after washing. This change in fabric texture will cause the clothes to twist after washing. Generally, customer requirements are within 3%–5%. This item is especially important for some large clothes, trousers, etc.
F Fastness: washing fastness, pickling water fastness, light fastness, chlorine bleaching fastness, rubbing fastness (dry, wet rubbing), perspiration fastness, color contrast Fastness etc.
G pilling: Pilling occurs when the cloth surface is rubbed. Generally, short fiber fabrics have poor pilling.
H Bursting strength, car blast holes: Car blast holes refer to the phenomenon that the suture needle punctures the fabric to form small holes when the fabric is being sewn into garments. Bursting strength refers to the pressure a fabric can withstand.
I Tensile force:
The elongation rate (Elongation) is the percentage that can be elongated under the action of a fixed force,
Rebound rate (Modulus) refers to how many grams of force it takes to pull to the specified length,
Recovery rate.�recovery) refers to how much it can be retracted after being pulled to a specified length and fixed for a period of time.
J WPI/CPI: collectively referred to as density, WPI refers to the number of weft loops per inch, and CPI refers to the number of loops per inch in the warp direction. This value is closely related to the specifications and shrinkage of the fabric. </p
