GuestMarch 1, 2024 AATCC Blog

Event, meetings, networking, industry topics, textiles, textile, color, lab, chemistry, colorists, program, conferences

I Remember When: My Top Ten List from the Textile Industry

By Don Carrigan

This past June, I reached a milestone in my textile career: I have worked 60 years in the industry (57 years as an AATCC member!) After obtaining a degree in textile chemistry, I started full time employment at Cannon Mills in Kannapolis, NC, USA. Managing the dyehouse there, we dyed 400,000 lbs. of towels and 200,000 yds. of bed sheeting each day.

After 14 years, I moved to the supplier side, working for BASF, DyStar, and Royce Global in technical service and sales functions. Since retiring at the end of 2016, I have worked as a consultant for Royce Global.

I have put together a count-down list of the 10 strangest things encountered during my 60 years in the industry:

 

TEN

Demethylation of C.I. Basic Blue 41 on Nomex.

Methylation is the very last step in the synthesis of basic blue 41. There always remains a small fraction (1-3%) of the unmethylated molecules in the finished dye. This unmethylated product is very red in appearance.

Royal blues comprise the largest portion of Nomex workwear. A dye customer had called, upset that his batch of royal blue Nomex fabric turned out (In his words) redder than the south end of a northbound fox. He was sure our dye was at fault, since it was a self-shade with only one dye in the recipe.

The next day I went to his plant in Georgia to review the formulas and procedures. They had included sodium hexametaphosphate as a water conditioner. In the mixing room, I noticed a drum of soda ash adjacent to the hexaphos. A lab dyeing was performed substituting soda ash for the hexaphos. We were able to reproduce the exact reddish shade he had complained about. The high pH of the soda ash and the high temperature (135C) of the dyeing procedure had demethylated a large portion of the Basic Blue 41 molecules.

 

NINE

Pressurized dye jigger explodes.

A very large capacity pressurized jig was installed at a dyehouse in South Carolina. This piece of equipment was immediately nicknamed “Jigzilla.” After many months of operation, a pressure relief valve started leaking requiring replacement. Unfortunately, the replacement valve was one set to open at a much higher temperature than the original.

At a later date, a malfunctioning steam valve failed to close when it should, causing the temperature inside the jig to rise to a point that caused an access door to be blown off. Fortunately, no one was injured by the door or the escape of steam from the kier. However, the door did strike an adjacent preparation range with such force that the range was destroyed.

 

EIGHT

Atmospheric jig dyeing at 230F.

I had the opportunity of working at a midwestern state prison that had a textile operation producing prisoner uniforms and law enforcement officer uniforms for various jurisdictions around the state. Yes, I have been to the “Big House.”

A 65/35 PES/cotton twill produced for prisoner uniforms was being dyed on a jig with disperse and direct dyes. I asked the manager at what temperature they were dyeing the polyester. He replied, “230F.” Noticing that this was an atmospheric jig, I couldn’t comprehend how they could reach that temperature. The manager had the operator start the machine for the polyester dyeing step. Sure enough, the thermometer on the machine shortly reached 230F. That’s when I noticed the thermometer’s probe was directly under the live steam pipe that was heating the bath.

 

SEVEN

Dark spots on light blue toweling.

We were continuously dyeing toweling a pale blue shade based on C.I. Vat Blue 6 at Cannon Mills in 1983. Periodically, dark blue spots about the size of a fingertip would show up. There was no repeat to them like you would expect with a hole in a pad roller. They probably averaged a spot every couple of yards when they occurred. The spots would usually stop after 50 yards or so. They might reappear again in 30 minutes, or it might be days later. No other shades were exhibiting this problem.

The lab did extractions on the spots. The extract was compared with the infrared fingerprints of every chemical product used at Cannon Mills. We were fortunate to have a very talented infrared spectroscopy technician. Nothing came close to matching.

We stripped the spotted dyeings with polyvinylpyrrolidone, sodium hydrosulfite, and caustic soda back to a white substrate. This stripped fabric was then redyed in a beaker with the original shade. The spot reappeared in the same location.

Another time, I noticed the spots on the fabric exiting the steamer. We immediately stopped the dye range, cut out the truck of towels that we were dyeing and returned them to the bleachery for a full rebleach. When we dyed those towels again, the spots were still appearing.

At the suggestion of a dye supplier, we rematched the shade using C.I. Vat Blue 66. We never saw another spot. The second best thing that can happen to a dyer is the problem goes away without learning the source of the problem.

I suspected that it was something cationic in the spot that attracted the anionic vat leuco. It is known that Vat Blue 6 would have a stronger attraction than Vat Blue 66 for cationic substances. Also Vat Blue 6 is much more sensitive to water hardness.

 

SIX

A Computer with 37K of RAM running a dyehouse in the 21st century.

I owned a Commodore 64 back in 1983. I taught myself BASIC programing on it. For a personal computer it was powerful for its time. It had 64K of RAM (but only 37K were accessible).

I was shocked to see a Commodore 64 running an entire jet dyehouse in eastern North Carolina. To be fair, it was not actually running the dyehouse. It was scheduling other computerized controllers than ran each individual jet.

 

AATCC Events and Textile Industry Events and Networking.

FIVE

Reducing agent and oxidizer side by side.

I was running a vat dye trial on an Argathen jet. Plant personnel had no prior experience with vat dyes. They had previously ordered a drum of sodium hydrosulfite (90%) for the trial. After arriving at the plant early one morning, I asked where the hydro was. I was taken to a basement storage area where I saw a drum of hydro physically in contact with a drum of sodium hypochlorite.

Here was a rocket engine waiting on ignition!

I told the supervisor that I would be waiting far away in the parking lot and to let me know when one of the drums was moved.

 

FOUR

Hydrogen sulfide generation at Cannon Mills.

At Cannon Mills Plant 1 in Kannapolis, there were two dyehouses, a 32 kier package dyehouse and a continuous dyehouse with five dye ranges. The dye usage of both dyehouses was over 90% vats. In addition, there were smaller amounts of disperse, reactive, naphthols, and pigments used. Both dyehouses ran a naphthol red shade on a weekly basis. In addition, there was a sulfur black shade dyed once a year or so in the continuous dyehouse.

As luck would have it, the package dyehouse was running this naphthol shade at the same time the continuous dyehouse was dyeing this sulfur black. Sodium sulfide was the reducing agent of choice at the time for sulfur dyes. When the strongly acid effluent from the naphthol dyeing came in contact with the alkaline effluent of the sulfur dyeing, the pH was lowered enough to convert the sodium sulfide to toxic sulfur dioxide.

If there was a house near a manhole in the line that carried the dyehouse effluent to the waste disposal plant, the white paint was noticeably discolored. Cannon Mills had to repaint several houses. Unfortunately, there was one fatality. A stray dog was discovered lying near one manhole. Immediate procedures were put in place requiring the continuous dyehouse to check with the package dyehouse before running sulfur black again. It could have been much worse.

 

summit

THREE

Debromination of C.I. Vat Orange 2.

We were called to a continuous dyehouse in South Carolina to observe a strange phenomenon. While dyeing an orange shade with vat orange 2, about 10% of the width of the fabric adjacent to the left selvage was noticeably yellower than the rest of the fabric. Suspecting a preparation issue, a square piece of the fabric was cut out and rotated 90 degrees and sewn back in. The yellower shade remained on the same side even though the selvages were now crossways. Another piece of fabric was rotated 180 degrees and again the yellower shade remained on the same side of the dye range.

When synthesizing Vat Orange 2, the last step is to brominate Vat Orange 9. This produces a dyestuff that is noticeably redder than Vat Orange 9. The dye range in question had high intensity xenon lights illuminating the fabric through the portholes of the steamer. This caused debromination of the reduced Vat Orange 2 for about a foot into the fabric, converting it to Vat Orange 9 which was yellower. This debromination only occurs in the reduced state, not the oxidized vat pigment.

The lights were replaced with lower intensity lights and the problem went away.

 

TWO

Theft and recovery of a stolen drum of dye.

We had a BASF customer using C.I. Basic Blue 141 on cationic dyeable polyester. They wanted us to produce a liquid version for them to use with their dye dispensing system. We had our parent company in Germany produce a trial lot that was shipped to the customer. This 25 kg drum disappeared somewhere between our loading dock in Charlotte, NC, and the customer’s plant in South Carolina.

Two years later, a caller from Greenville, SC, was transferred to me. He had just bought a house in Greenville and discovered a drum of dye in his basement. He saw our name on the drum’s label. He read me the name of the dyestuff. It was the missing drum of Basic Blue 141.

Then he offered to sell the drum back to us. I told him it was stolen property, and did he really want to involve the police in this matter? At this point he became more cooperative. I did offer to buy him lunch in Greenville. I met him the next day and he handed over the drum to me. I carried the drum back to our Charlotte plant and set it up on our loading dock.

We opened the drum to discover it contained used motor oil. I guess the thief, upon discovering that he couldn’t sell the dye, repurposed the drum.

 

AND THE NUMBER ONE STRANGE OBSERVANCE

Dusting of C.I. Basic Blue 3 Liquid.

We received a call from an acrylic dyer in eastern North Carolina. He stated that our Basic Blue 3 was dusting badly and was spreading throughout their mixing room contaminating other products. “Wait a minute,” I replied. “Aren’t you using our liquid version?”

While visiting the plant the next day, I discovered he was right.  Blue specks were visible on the surface of buckets of chemicals sitting next to mixing tanks. I blew my nose and my handkerchief had blue specks on it. How could this happen?

Upon reviewing the dye formula for this particularly heavy shade, I discovered that the concentration of C.I. Basic Blue 3 in the relatively small mixing tank had encountered its miscibility gap. For those of you unfamiliar with this term, allow me to explain. Basic dyes require solvents, usually acetic acid, to stay in aqueous solution. At low dyestuff concentrations, little solvent is needed. In the drum, the 100% product is in solution. But there is a miscibility gap, different for each dye, usually between 400 and 700 grams per liter, where the concentration of solvent in grams per liter is not sufficient to keep the dye in solution.

They had encountered this miscibility gap in their mix tank. A high-speed exhaust fan inside the closed tank was actually sucking particles of dye and spreading them throughout the room. The problem was solved by dividing the dye mix into two separate drops, effectively cutting the dye concentration in half in the mix tank to avoid the miscibility gap.

 

I don’t know how long I will continue working in this industry. But I suspect these strange encounters will continue!

 

Many AATCC members remember the “I Remember When” series in Textile Chemist & Colorist, and the “I Remember When” booklet—a collection of strange and funny stories from members working in the dyeing and finishing industry “back in the day.” This blog post harkens back to those stories.

BEST VIEWED IN CHROME AND FIREFOX BROWSERS. We use cookies to ensure that we give you the best experience on our website. By using our services, you agree to our use of cookies.

Okay