Development Of Printing And Dyeing Pretreatment Technology

Textile printing and dyeing industry and

The improvement of the product level is a systematic project. The above and below are interrelated. Whether the pre-processing can be further processed is mentioned in the author's last article. For example, the proportion of "three without one essence" in the technical pformation of cotton spinning and weaving industry (that is, no roll processing, no joint yarn and shuttle free weaving) and the increase of the proportion of combed yarn have laid a good foundation for the improvement of the variety, specification and quality of our printing and dyeing products, and also reflects the awareness of the upstream products serving the downstream products.

Because of this, many product quality problems or environmental problems often occur in printing, dyeing, processing or products, but not in printing and dyeing processes, such as:

(1) the mixing of "three silk" (i.e. foreign fiber) is caused by raw materials or spinning mills, but it has a great impact on the final quality of printing and dyeing products, or increases the workload of troublesome elimination, prolongs the processing time and increases the cost, and also affects the quality.

(2) the cotton seed hull problem, the ginning factory and the spinning mill should be more active. It will crush the cottonseed hull, mix it in the cotton, go to the spinning mill to clip it in the yarn, and make it more tightly in the weaving factory, then let the printing and dyeing pretreatment process be removed. Is this a bit difficult for printing and dyeing?

(3) the problem of PVA pulp, which is the need of the Loom factory. In order to reduce the breakage of the yarn, this kind of slurry is relatively cheap, the sizing quality is good and the wear-resistant, especially in order to adapt to the current high-speed loom, the sizing rate is higher and higher, such as selling the bad cloth while selling the paste, but the slurry has a great deal of harm to printing and dyeing process, and desizing is the most basic step of printing and dyeing pretreatment, which is related to the final effect of the pretreatment.

PVA slurry is not easy to degrade, desizing, difficult to recover, and difficult to recover, which results in a very high COD of desizing residue.

The quality and processing cost of printing and dyeing have caused a big problem. The problem of enzyme desizing and boiling is very popular. The problem of PVA pulp is more complicated, but the effect is bigger. The relevant units are discussing whether the technology should be included in the "double high" list.

　　(4)碱减量问题，在化纤仿真产品中的一个常用工艺，而且减量率多比较高，“碱剥皮”下来的残液COD 极高，还不易降解，目前特别在浙江等地还有相当数量的企业采用这种办法，主要由于我国生产的大部是常规涤纶，以往生产细旦，超细旦纤维的工艺技术跟不上，异型纤维的生产能力跟不上，而且成本高，因此，只能用上述明显不合理的碱减量工艺，也即用强、浓碱把常规较粗的涤纶纤维“变细”(俗称“碱剥皮”)以此改善常规涤纶的染色性和服用性能(如手感和悬垂性等)，有利于使化纤仿真印染产品的碱减量工艺被逐步取代，仅作轻微的减量或不减量，以此减轻环保压力，有关单位正在研究拟将碱减量工艺列入“重污染”之列。

The following four examples are cited briefly.

In the upstream raw materials or processing technology, environmental protection and product quality are attached to the pretreatment of printing and dyeing. Therefore, to improve the effect of energy saving and emission reduction in printing and dyeing process, it must be a systematic project from top to bottom, and even to the horizontal. The final problem is exposed to dyeing, printing and processing, and products. The source of the problem is not always produced in printing and dyeing.