In the dyeing and finishing of knitted fabrics, oil stains, stains, color stains, color flowers, silicone oil spots, etc. on the cloth surface are often encountered, resulting in a decrease in product quality, and some cannot even be repaired. To this end, it is necessary to find a degreasing agent with high emulsifying, dispersing and dissolving ability. In the production practice, the DK808, a high-efficiency degreaser, was used appropriately and flexibly, which achieved unexpected results and solved some difficult production problems for the dyeing plant.

1. Composition and properties of high-efficiency degreasing agent DK808

The chemical composition of the high-efficiency degreasing agent DK808 is a compound of anionic and nonionic surfactants and aromatic solvents. The appearance is a colorless and transparent liquid with a pH of 7.5 ～ 8.5 (1% water emulsion). Easily dispersed in cold water. It has excellent emulsifying, dispersing and dissolving ability to paraffin, grease and pigment stains, and has good washing effect to waxy and oil stains adhering to fabrics. Therefore, it is suitable for removing loom oil, lubricating oil and front spinning oil on various fibers. It can also be used as scouring agent, detergent, emulsifier and de-floating agent.

Second, the application of high-efficiency degreasing agent DK808 in the dyeing and finishing of various knitted fabrics

A. Application in pretreatment of various knitted fabrics

The pre-treatment of various knitted fabrics is mainly to remove the oil used in fiber manufacturing and weaving and the oil stains during transportation and storage. It is often found in production that some T / C and CVC blended knitted fabrics contain certain oils added during weaving. If no oil remover is added during scouring, "color flowers" will appear during dyeing (mostly cloth Uneven red block on the surface), which is often encountered in the dyeing of CVC and T / C fabrics. If we only find the cause of dyeing from the dyeing aspect, we cannot fundamentally solve the problem.

Heavy oil stained polyester, nylon and other synthetic fibers and their blended fabrics are difficult to wash, and the oil stain must be removed before dyeing. Otherwise, after high temperature dispersion dyeing, the oil stain and the disperse dye will undergo a chemical reaction under high temperature conditions to cause difficult to remove lakes. Therefore, oil stains must be removed before dyeing.

1. Application example of high-efficiency degreasing agent DK808 in pure synthetic fiber fabric

Fabric variety: pure polyester or nylon knitted fabric

Equipment: Rope Q113 (bath ratio 1:25), or high temperature and high pressure overflow dyeing machine (bath ratio 1:12)

Prescription:

Soda ash (g / L) 0 ~ 2

Efficient degreasing agent DK808 (g / L) 0.3 ~ 2

Processing conditions: 90 ~ 98 ℃ × 20 ~ 40min

Note: The Q113 rope-shaped machine has a good degreasing effect. It is easy to wash off the emulsified oil to prevent recontamination, but some fabrics that are easily wrinkled are not suitable for processing by this equipment, and need to be moved to a high-temperature machine for dyeing after degreasing. ; The high temperature and high pressure overflow dyeing machine is relatively small, but the oil that has been emulsified from the cloth surface may be stained again, and it is prone to blistering. If the operation and process are proper, the cloth surface will not crease.

The dosage of high-efficiency degreasing agent DK808 should be determined according to the actual oil type and oil content of the cloth. For those who are difficult to remove and have high oil content, the dosage should be increased appropriately.

Some printing and dyeing factories think that the higher the temperature during degreasing, the better, and even use 130 ℃ degreasing, but in fact there are advantages and disadvantages. Because some oils are easy to emulsify under high temperature conditions, but some oils are not. To this end, many auxiliary plants have launched low-temperature degreasers, both to achieve the purpose of degreasing, but also save energy and save time.

    2. Application example of high-efficiency degreasing agent DK808 in the pretreatment of synthetic fiber blended fabrics

Fabric variety: T / C, CVC blended knitted fabric

Equipment: high temperature and high pressure overflow dyeing machine (bath ratio 1:12)

Prescription:

Scouring agent (g / L) 0.5 ~ 1

Efficient degreasing agent DK808 (g / L) 0.3 ~ 2

30% NaOH (g / L) 3 ~ 4

27.5% H2O2 (g / L) 6 ~ 10

Defoamer (g / L) 0 ~ 0.2

Process conditions: 98 ℃ × 45min

Description: The key to degreasing of T / C and CVC blended knitted fabrics is prevention. General oils can be removed before high temperature dyeing. However, if the oil agent is not removed during scouring or bleaching, the oil agent may easily react with the dye or other auxiliary agents to cause color flowers, color stains, oil stains, etc. during high temperature dyeing. The dosage is also difficult to remove. Therefore, the most reliable method is to add high-efficiency degreasing agent DK808 when scouring and bleaching for one bath.

B. Application of high-efficiency degreaser in dyeing

Purified fiber fabrics can be dyed with high-efficiency degreaser DK808 before dyeing before dyeing, which can effectively prevent color stains, color flowers and tar spots during the dyeing process. But degreasing and dyeing are carried out in two steps. After all, the dyeing cycle is extended, which contradicts the guiding ideology of "fast delivery". Therefore, the one-step method of degreasing and dyeing is undoubtedly a "saving" method. However, it is undoubtedly important to choose a suitable degreasing agent: both to achieve the effect of degreasing, but not to reduce the dye uptake rate and cause changes in dye shade. After screening, we chose the high-efficiency degreasing agent DK808 to carry out the one-bath degreasing and dyeing experiment, and achieved certain results. Here is an example:

Fabric variety: pure polyester knitted fabric

Equipment: high temperature and high pressure overflow dyeing machine (bath ratio 1:10)

Prescription:

Disperse dye (o.w.f.) (%) X

98% HAC (g / L) 1 ~ 1.5

High temperature levelling agent (g / L) 0.5 ~ 1

Efficient degreasing agent DK808 (g / L) 1 ~ 2

Processing conditions: 130 ℃ × 45min

Note: Not all degreasing agents are suitable for degreasing and dyeing one bath, because many degreasing agents are more alkaline, and some are even strongly alkaline, such as degreasing agent TF-101 (it is mainly used for dyeing Pre-treatment degreasing). The 1% aqueous solution of the high-efficiency degreasing agent DK808 has a pH value of 7.5 to 8.5 and is not alkaline. It can be used for degreasing and dyeing in one bath. However, it should be noted that the amount of glacial acetic acid used should be appropriately increased, so as not to increase the pH of the dyeing solution and affect the dye uptake rate or cause changes in shade.

For some heavy oily fabrics, it is recommended to use the process of degreasing first and then dyeing.