Common defects in printing products - flat screen printing (4)

(iv) Rickets caused by steaming

1. take a color
(1) Form: On the surface of the silk, there are spots where flower or ground color irregularly stick to each other. This is a common culprit in the steaming of a cylinder steamer.
(2) Cause:
1 When steaming, the interlining cloth is too wet, unclean, or has a hole, and it is laid on the surface of the silk.
2 When steaming, the humidity is too large and the silk surfaces are in contact with each other.
3 After the steamed finished fabrics are out of the box, they are piled together without cooling.
4 The dye concentration is too high, the color fastness is poor, or the moisture absorbent is excessive.
5 Discharge printing was not steamed in time.
6 If the washing temperature is too high, the fabric is over-processed, or the desizing process is not clean, the fixing process is performed.
7 After washing, it is not finished in time.
(3) Preventive measures:
1 Steamed lining cloth should be washed, replenished and dried before use.
2 Control the humidity in the steaming box. The fabric capacity in the box should not be too much, especially when using a steam drum for steaming.
3 The steamed fabric should be cooled and then washed.
4 If possible, use dyes with high color fastness and master the maximum amount of dyes.
5 Discharge printing fabrics and steam them after printing, especially in rainy weather.
6 Washing follows the rules of cold wash, warm wash, hot wash and cold wash, and it must be removed and then fixed.
7 Wash in a timely manner.

2. Color depth, color depth, depth, front and back depth (1) Form: Color or color on the fabric surface, there are differences in the color of the left and right or front and rear ends.
(2) Cause:
1 The use of cylinder steamer steaming, due to the humidity of the upper and lower parts of the box, it is easy to make the printed fabric produce shade.
Another reason is: steam instability, time is too short, different density of hanging silk, wet uneven even before steaming.
2 Sterile dyes are used in color pastes, especially dyes that are particularly sensitive to humidity or temperature.
3 When printing, scraper angle, pressure is inconsistent, or the pattern holder is not flat.
(3) Preventive measures:
1 Strictly enforce the technical requirements for the steaming of the drum steamer: the steam supply is normal and stable, the lining cloth is tight and moderate, the amount of hanging silk is moderate, the density is loose and uniform, and the steam is uniformly wet before steaming. For those who have serious irregularities, they should turn around and steam again.
2 Select dyes with good stability.
3 Adjust the scraper and flower bracket before putting it on the machine. Check and correct it at any time.

3. Printing water stains (1) Morphology: Some patterns on the surface of the silk are irregularly osmotic, even blurred.
(2) Cause: There is a drop of water on the surface of the cloth before steaming. There is no cover lining on the top of the cylinder steam box or there is a hole in the top lining cloth.
(3) Preventive measures:
1 After the fabric is printed, it should be placed in a dry place with no fog or moisture to prevent it from dripping.
2 Before steaming, warm up the tank and drain the exhaust gas and condensation water.
3 Timely replacement of cloth, belts, cloths, continuous steamer to prevent the top of the product water, and often pay attention to the import and export of printed fabrics.
4 When the steaming is completed, lift the box out in time to prevent condensation from dripping.