Common problems and solutions in the dyeing process(1)

1.Colour difference

Dyed products have different shades of colour and light. According to the difference of the colour difference is divided into the same batch of colour difference and the same horse colour difference. The same batch of colour difference refers to the same batch of products, a colour number of products, boxes and boxes, pieces and pieces, packages and packages, pi and pi between the existence of colour difference. The colour difference of the same pi refers to the colour difference between the sides of the same pi, the colour difference between the front and back or the colour difference between the front and back of the same pi.

Causes

1).The reason of grey fabric

2).Dyes are not evenly distributed on the fabric first.

Fabric factors (fabric sizing)

Liquid-absorbing factor (liquid absorption, uneven penetration)

Pre-drying factor (uneven drying)

3). Different degree of fixation of dyestuff on fabric: improper control of fixation conditions (e.g. baking)

4). Improper selection of dyestuff

5).Dye colour and light variations

Pre-dyeing factors (whiteness of semi-products, pH value, etc.)

Dyeing factors (e.g. too high temperature)

Post-dyeing factors (process and additives in finishing)

Soaping factor

6).Operating reasons: uneven chemical material, improper addition of material; uneven cloth on roll dyeing.

Solutions

1). Strengthen the blank inspection to ensure the quality of blank cloth.

2). Select suitable equipment, use uniform rolling or improve the uniformity of rolling.

3). Strengthen the management of training and bleaching, and provide qualified semi-products.

Use the same blank for the same batch of dyed goods

Dry the cloth surface evenly before dyeing

The shaping effect before dyeing should be even

Control the pH value of cloth after mercerisation to be neutral.

4). Reasonable selection of dyestuff (similarity of dyeing curves, strengthening of dyestuff testing, etc.).

5). Add levelling auxiliaries when dyeing.

6). Reasonable dyeing process

7). Pay attention to the post-dyeing treatment, washing and soaping should be sufficient.

8). Selection of finishing auxiliaries should be careful, and process conditions should be consistent.

The colour does not match the sample

The colour of the finished dyeing product does not match the colour of the specified samples, and exceeds the permissible colour difference standard. Performance: does not match the same kind of cloth samples (production samples and original samples of the same fibers, the same tissue of the colour samples), does not match the reference sample (different raw materials and different tissue of the colour), does not match the transaction of small samples (provided to the customer and the two sides to determine the samples), does not match the digital samples (provided by the customer with a computer colour matching system of digital samples)

Causes

1). The development of improper dyeing process, the size of the sample production conditions are not the same

2). Audit colour sample light source is not uniform

3). Dyeing plan is not well arranged

4). Dyes, auxiliaries, batch management is not good

5). Dyeing process conditions, operation mastery is not good

Semi-products do not meet the requirements

Dyeing with hard water

Improper management of dyeing

The amount of dyeing material is weighed wrongly

Dyeing without strict mastery of process conditions

Solutions

1). The organisation specification of the big and small sample fabrics should be the same, and the semi-products process should be the same;

2). The pressure of rollers should be fixed when rolling and dyeing, and the bath ratio should be consistent when dipping and dyeing;

3). The size of the sample of the same dyeing process conditions; (dyes, auxiliaries, temperature, bath ratio, etc.)

4). Dyes should be screened, easy to change colour dyes are not used.

5). The use of standard light source (or computer colour measuring instruments)

6). Reasonable arrangement of dyeing production plan

7). Strengthen the management of dyes and auxiliaries

Strict process discipline

Grasp the three levels of inspection (self-inspection of blockers, inspection of team and workshop).

Master the process conditions, ensure that the car according to the process

Grasp the sample of each car or each vat of cloth, and post the sample system.

Edit by Edie

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