To achieve a successful dyeing, it is necessary to select suitable dyes and auxiliaries with stable production, good reproducibility, and establish a "zero defect" management system. The system includes establishing perfect operation guidance standards and dyeing process tracking, supervision and spot check methods; requiring online management records of all parameters of dyeing process; establishing control and accounting methods for grey fabrics, water, dyeing auxiliaries, acids, alkalis and salts, as well as the quality of dyeing products control standards, etc. Modern printing and dyeing enterprises generally use computer color matching systems, automatic batching and feeding machines and automatic duplicating machines to realize production process automation and computer management modernization, and provide sufficient "hardware" conditions for improving the one-time pass rate of proofing, duplicating, lofting and production dyeing . However, more importantly, it is also necessary to improve the level of process design, the quality of staff, the accuracy of proofing and replicating, the one-time success rate and online reproducibility of production stakeout.

1. Document review, proofing and management

1.1 Review of standard samples

Standard samples refer to customer samples for analysis. The content of analysis mainly includes the standard light source for raw material composition and shade evaluation, the grammage, specifications of the fabric, whether there are special requirements for dyeing fastness, physical index requirements such as strength and shrinkage rate, and whether there are special finishing requirements, etc. It is necessary to carefully read the customer's order requirements to fully understand the customer's needs and formulate specific technical solutions.

In the review of the order, for the conventional varieties, after receiving the order, it can be transferred to the color-sampling program. For special varieties, such as high-count and high-density, light and thin, new fiber products and varieties that have not been done before, a preliminary production sample test must be carried out to ensure that various physical indicators basically meet customer requirements, and to verify the feasibility of large-scale production. When the width, gram weight or single-dyed blended products cannot meet the customer's requirements, corresponding measures should be taken actively. At the same time, we must actively communicate with customers, try our best to meet customer needs, and quickly provide customers with good thugs. For orders with clear technical requirements, the technical level and production capacity of the company should be considered while meeting customer requirements. Lists without specific requirements are generally arranged in accordance with national standards. For orders with special quality requirements and functional finishing requirements, if not fully grasped, pioneer production tests must be done to ensure the quality index and delivery time of product quality.

The customer's standard sample should be well preserved, and should not be directly exposed to light, exposed to the sun, or stained and discolored. The color matching light source should be calibrated regularly, and the color matching of the light source of the standard light source box should be uniformly used. Because the color of the inner wall of different light boxes is different, the refraction on the sample yarn and sample cloth will cause inaccurate color matching; the fluorescent material in the lamp tube is different, and the reflection spectrum of the same cloth is also different, thus showing the difference of excellent light. Therefore, both the laboratory and the workshop must be consistent with the customer's color matching light source. When the customer only requires a single light source, such as CWF, TL84, D65, etc., it is best to test the color under other relevant light sources (fluorescent light, natural light, etc.) to avoid the phenomenon of "jumping lights" under different light sources.

1.2 Determine the production process

Determine the production process according to the enterprise equipment. When proofing, according to the large production process equipment, the dyeing materials and process flow are correctly selected. The proofing conditions should be as consistent as possible with the production conditions of the dyeing process; the dyes, auxiliaries and dyed fabrics used in duplication, lofting and mass production must be consistent; the determined technological process and technological conditions cannot be changed at will; the amount of dye can be adjusted according to The practical experience of large and small samples and the characteristics and laws of the equipment used are fine-tuned.

1.3 Selection of dyes and auxiliaries

According to the customer's standard sample's requirements for dyeing depth, shade deviation, color brightness and dyeing fastness, dyeing and chemical materials are selected according to the compatibility performance.

Dye selection principle:

(1) Select dyes with high strength, high dye uptake and high wet rubbing fastness for deep and dark colors.

(2) For light and medium colors, choose dyes with high levelness and high color fastness.

(3) For those with high requirements on perspiration fastness, chlorine bleaching fastness and light fastness, imported special dyes can be selected.

(4) For those with high requirements for dry cleaning fastness, choose organic solvent-resistant dyes.

(5) For mercerized varieties after dyeing, choose alkali-resistant dyes.

(6) Yarn dyeing, in order to prevent the color-matching of yarn-dyed products, dyes with good washing fastness should be selected.

(7) For yarn-dyed fabrics that need high temperature setting after dyeing, high temperature resistant dyes should be selected in order to prevent "flying color".

Auxiliary selection principle:

It has good levelness, strong permeability, good dyeing assistance, and does not affect the dyeing shade.