Cotton scouring is to remove impurities and kernels and improve wool efficiency.People have tried lipase to remove cotton wax, with protease to remove nitrogen, to achieve the purpose of boiling, have not been successful, now using laccase to bleaching pulp has been successful.Laccase is peroxidase, it can make lignin demethylation to achieve the effect of delignification, can also make the reactive dye not dyed with fiber oxidation and removal, to achieve the cleaning effect.Bayer's product, BaylaseRP, is called peroxidase, which can be used to wash reactive dyes after dyeing.Using laccase and auxiliary mediator together with hydrogen peroxide source can remove the pigment on cotton, also can remove cotton seed shell, to achieve the purpose of bleaching.By mixing the above enzymes together and supplementing with activator and surfactant, one bath process can be carried out by deboiling and bleaching in the same bath, saving water and energy.
After dyeing printing, unfixed dyes and pastes should be removed by soaping. Soaping is carried out at above 95℃ to exert maximum effect.Therefore, it is necessary to develop a cleaning agent that can also play a good effect at low temperature.For example, sodium alkyl diphenyl ether sulfonate can be soaping at 40℃, and long branched chain fatty alcohol polyoxyethylene ether can also reduce the temperature of soaping. At present, many researchers are looking for suitable low-temperature soaping agents.
Cold rolled stack dyeing has been used to dye cotton with reactive dyes in China, but it is not widespread.It is reported that cold-rolled pile dyeing can be used for VAT dyes, sulphide dyes and even wool dyeing.It is characterized by room temperature dyeing, energy saving and water saving, simple equipment, suitable for small batch, many varieties, good dyeing repeatability, no crepe strip.In China, there is a lack of systematic research on reactive dye cold-rolled pile dyeing. Only dye, penetrant and alkali are prepared for dipping and rolling, and piled for 6-8 hours before washing and soaping.The quantity of color is not as high as that of wet steaming, and the dyeing effect is not ideal.
To do a good job of cold rolling reactor, at least the following aspects should be studied: rational selection of reactive dyes;Reasonable selection of permeants, the key of cold rolling pile dyeing and finishing process is to use high quality permeants, help the dye into the fiber quickly;Choose the alkali agent used for fixing color, compound alkali agent has been widely used abroad, Shanghai Qirui Textile chemical company has produced;The uniformity and fullness of dyeing can be improved by selecting special levelling agent for reactive dyes, but there is still a lack of levelling agent for reactive cotton dyeing in China.If the auxiliaries with the above functions can be prepared to improve the quality of cold rolled heap dyeing, it will certainly promote the popularization and application of cold rolled heap dyeing.
Penetrating agent:
The broad concept of osmotic agent refers to a class of chemicals that help the substance to be permeated to the substance to be permeated. Industry generally uses surfactants (which can be anionic or non-ionic) or organic or inorganic solvents.
