Experience Talks - Yarn Dyeing.

Some time back , one of my agents mailed to me that one of our large customer was about to migrate to " Dyetubes" against " Dyesprings". On further researching, this was the story.

This customer is one of the largest yarn dyer in SE Asia. He had been using dyesprings or the last 20 years , but for quite some time was experiencing a very unique problem in dyeing, wherein the packages on the upper end of the column would have black particles on the surface between two packages and these would get washed out easily with normal water. Which means, the dyeing was not a problem, however, the black particles were sitting between one package and the other and only middle up of the column of dye packages.

As usual, all Industry Experts set in action and the following got tried.

New Set of Chemicals to remove the black particles.

Higher pump pressure.

Longer washing cycles.

Then someone advised, well, it was coming from the winding machine , as the dyer was using random winder . He changed his winder to precision winder , but the black particles remained intact.

Another expert stepped in and said, well the other companies use Non Compressible Dyetubes and this customer is using Dyesprings, therefore he has a problem. The non compressible dyetubes will have some space between the two packages and the washing cycle therefore would remove the black particles . Customer was quite impressed and he wrote to me for the supply of Dyetubes for the trials.

After listening to the full story, I was convinced, there was some simple issue , which no one is able to see , because if black particles are coming only above middle length of the column, then it has something to do with either the pump pressure or there was some detioration of dyes or detioration of chemical as black would mean carbon deposits and this can come only on breaking of carbon chains.

Nevertheless, I flew to the customer and audited the whole process again. Everything was normal. The density of packages, the flow , the time, the chemicals, washing cycle etc etc. And yet the packages on top and middle end of column of dyeing machine would show these black particles, which got washed out with water.

I recalled that when I was entering the factory, I had seen ahead of me a Truck carrying Coal for the boiler. So, I inquired with the customer , did he change lately from the oil boiler to coal boiler. He confirmed that on account of rising oil prices, the whole industry was moving to coal boiler.

Next thing I did was to go the creel of packages awaiting dyeing. The packages had deposits of carbon lined against the wall, some seen with naked eyes and some could be brushed with force.

It was clear within minutes that the Boiler was the culprit and not the dyeing machine, nor the winding machine , nor the dyesprings, nor the chemicals or auxiliaries. But, how all the local industry experts in that country had tried all the stunts, without trying to think logically that if the process had a weakness, then it would show on all the packages and not just selectively. And ofcourse changing dyesprings to dyetubes was making the system still poorer and weaker.

The pump pressure would force the carbon particles for all packages till the middle level of the column and thereafter the force was never enough to remove the carbon deposits. This was causing the black particles to remain there and get washed out only when the package was removed and washed.

The department was then sealed against outside air and the water being used in dyeing was also sealed against any chance of carbon invasion.

The customer Dyed Happily Ever After.

Moral of the Story : Whenever you see Black or other washable deposits on your product line, there has to be some source of carbon pollution around. Before tampering with your machines and processes, check for carbon, sulphur or another pollutant in the environment.