Fluorescent Pigment Dyeing

 These days garment dyeing has been very common and very attractive to entrepreneurs. The major supporting bars are low investment, Variety of color and wash down effect, which can be achieved through same machinery with change of Dyes/Chemicals and processes. There is no limit to what can be achieved with this techniques.

Normally bleached twill/Knit with and without Lycra is procured/purchased and stitched in house to make garments. Woven twill for bottom wear and Knits for making T-Shirts and Hoodies.

These articles are then loaded to machines. Two kinds of machinery which is very famous here in this part of World is either Barrel Machine or Front Loading Machine.

 

Front loading machines have become very popular. As these are more controllable and can be programed to start/stop, In take chemicals, Dose/Inject and KMNO4 can be sprayed to garments. Sometime called Batik Effect. These are of course expensive compared to barrel machines. Major brand is Tonello Machinery.

Whereas with Barrel machines manual temperature and chemicals dosages are controlled. Chinese barrel machine suppliers have embedded automatic system in these machines also. With these atomization these can also control Temperature and PH and can perform several other important tasks.

Most of the textile dyer avoid pigment dyeing as according to them it would be difficult to wash off remains of binder on the machine but those days are gone. With today technology and available polymers it’s not a issue at all. We have done some working with different chemicals to show you the quality of levelness and shade which can be achieved with new performance dyes and chemicals.

 Today in pigment dyeing, top of the list is Fluorescent pigment dyeing. One can achieve excellent levelness and great results.

Phenolic Yellowing

Yellowing as name called on very pale to full white fabric (Knit/Woven). Recently, had chance to visit a towel facility who is facing yellow streaks on towels.When full white OBA treated towels were tested for core ph. it was fount that ph is above 8.5 and present of Nitrogen dioxide in air has triggered the reaction.The wet storage for long period further catalyzed the yellowing.

A good definition of phenolic yellowing is expressed as "Yellowing is caused due to the presence of phenolic compounds on the textile material, reacting with the oxides of nitrogen in an alkaline medium. "

Oxides of nitrogen are generated in warehouses/households from direct heating systems or from automobile emissions in the urban environment. Neither the oxides of nitrogen nor the phenolic compounds by themselves cause yellowing, but when united, form the yellowing products.

BHT (Butyl Hydroxy Toulene) is added in polyethylene bags as anti oxidant to increase life of packaging bags and avoid air oxidation/Aging. It is good as for packaging material but, when this BHT reacts with textile material it caused yellowing. So, textile materials are often advised to not be placed in poly bags which have anti oxidents like BHT.This chemistry of BHT is low in cost and highly effective. Due to its low vapor pressure it is volatile and can be transferred to textile goods easily.

Polyamide (Nylon) is more prone to yellowing than cotton. This is due to the cationic amino groups present which react with anti oxidants.

Archroma product UMIDOL APY reacts with these cationic amino groups and block them to react with Anti oxidant and hence chances of yellowing minimizes.