::: EKSOY TEXTILE CHEMICALS & DYES :::


1		Blue 19-Blue R Dyeing
2		Blue 21 Turkis HFG Dyeing
3		Decolorization or Partial Stripping
4		Sublimation Thermomigration
5		What are some important points for achieving level dyeing in jet dyeing with reactive dyes.
6		In our dyeing plant, we have jets with different bath ratio and cırculation speed. Does it cause any problem relating my dyeing efficiency?
7		I have some specks on my reactive dyed knits which are romoved if I rewash with acetic acid. How can I prevent the formation of these flecks.
8		We dye cotton knitted material by exhaustion system. In the lab, wet rubbing fastness is superior to that of factory bulk production. We concluded, fastness difference and shade change comes from washing efficiency difference in lab. and bulk dyeing. Can you explain the theory behind it
9		In my cheese dyeing unit, I have the problem of in-out difference tensile strength, loss and softness. Although, I tried different kinds of scouring chemicals and softeners, problems are not solved satısfactorily.






















		Blue 19-Blue R Dyeing
		Q: It is rather hard to level dyeing with blue 19. Is there any proper method, dye and chemicals to dye with no head-ache?
		A: Blue 19 is a vinyl sulphon based dye with brilliant shade and widely used. Due it’s reactivity-substantivity, it creates problems.
		When Blue 19 is dissolved in water, it is in sulfato ethyl sulfon form, whose water solubility is very high but very low affinity to the fibre. By the addition of alkali, it converts to vinyl sulfon form, whose solubility is very low but high affinity to fibre. That means it attacks to cotton very rapidey.
		Kimsoline Blue Rsp has high solubility in vinyl sulfon form so it does not create any specks on the fabric. Besides dyestuff, we advise, an anionic dispersing/levelling agent to ensure level dyeing. Exolube NC is a powerfull dispersing-levelling-lubricant for this purpose. We also advise incremental addition of salt and soda for proper exhaustion of Blue Rsp. as shown below.
		Sodyum Sulphate is more preferable against Sodium Chloride.


		Blue 21 Turkis HFG Dyeing
		Q: My reproducibility rate with Turkis(Blue 21) shades is very low and washing time is rather long. What measures should I take to improve my dyeings.
		A: Turkis blues are phtalo cyanine based dyes with copper or nickle in the chromophore. Turkis blue dye molecules are double size of ordinary bifunctional dyes. So for the level dyeing, these big molecules need high energy-that means 80⁰C dyeing temp.- and long time- that means 60-90 min.- for proper and uniform migration and fixation. If the conditions are not followed fully, for example 60⁰C or 30 min., dye will not be fixed and will be washed out during rinsing time, hence low repeatibility and long washing period Primary exhaustion level of Turkis HFG is rather high. So sulphate addition should be performed incrementally to ensure ideal absorbtion of dye. In order to improve migration, longer time is required between salt and soda addition time.


		Decolorization or Partial Stripping
		Q: It happens sometimes to strip the dyeing partially or fully. Please advise me an effective recipe.
		A: In case of incorrect matching of desired shade, or unlevel dyeing, partial or full decolorization is necessary.
		Partial Stripping %10-30 Reduction

		Depending upon the degree of decolorization,
		Soda ash 10-20 g/lt
		Exolube NC 1,0 g/lt
		Exoline 3025 2,0-3,0 g/lt
		Liquor Ratio 1:10
		Temp.,⁰C 95
		Time., min 30-60
		Full Stripping
		Megaclear 12 2-4 g/lt
		NaOH, solid 4-5 g/lt
		Exolube NC 1-2 g/lt
		Temp.,⁰C 95
		Time., min 30-60
		In case Turquoise HF-G, Megaclear 12 and NaOH amount is increased by 30 percent.
		Fixing and De-fixing
		Q: a) During the dyeing of dark shades, color fixing changes the shade, which creates head-ache.
		b) We occasionally come across the need for de-fixing in order to make shading. What should I do, for trouble-free stripping of fixing agent.
		A: a) In case of Kimsoline dyes, dye- fixing is not required, if advised dyeing processes are applied and thouroughly washed by Exoline 3025 : 0,5 ml/lt.
		If fixing is necessary, Colorfix NF 250 can be safely used with no shade change. It is formalin free.
		Colorfix NF 250% 0,5-0,7
		pH 7
		Temp.,⁰C 50
		Time.,min 20
		Cationic or nonionic softeners can be also given in the same bath.
		b) In case of need detix of Colorfix NF, acidic treatment is applied
		Acetic Acid,%85 2-5 ml/lt
		Exolube NC 2-3 ml/lt
		Temp., ⁰C 80
		Time, min 20-30
		In order to remove thouroughly cationic fixing agent before shading fabric is washed with
		Exolube NC 1 ml/lt
		Temp., ⁰C 95
		Time, min 30
		If decolorization is necessary, after the first step, partial or full stripping is performed as explained in proper section with Megaclear 12.

		Sublimation Thermomigration
		Q: We are producing PES/VIS melangefabric and jet dyed fabric. We check the washing fastness before sending the fabric, but fiberdyeol two monts later we receive reclamation. What is the reason?
		A: In Physics, sublimation is the chanhe, from solid to gas without passing the liquid state. In case of dyed polyester fibers, dispers dyes migrate from the core of fibre and passes into atmosphere and stain the neighbor fibre, when the fabric is treated at above 150⁰C , like heat setting, ironing or post curing.
		Sublimation property of dispers dyes is directly related to their molecular size, namely, small molecules have poor sublimation fastness. Kimsoline dyes are classified in three groups.
		S Type : Excellent sublimation fastness
		SE Type: Relatively good sublimation fastness and good levelling property
		E Type : Poor sublimation fastness but excellent levelling property.
		Sublimation fastness of polyester dying also depends on
		- Dyeing strength,
		- Reduction clearing efticiency,
		- Heat set temp.
		- Finishing chemical.
		If dyeing depth is very low, i.e. in pale shades, even E type dyes have good fastness as shown below.

		A strong reduction clearing also helps to reduce sublimation staining.
		Megaclear 12 is a very strong and odor-free chemical
		Megaclear 12 0,5 g/lt
		NaOH, fl. 2,0 g/lt
		Exolube NC 0,5 g/lt
		Temp,⁰C 95
		Time, min 20
		Even with S type dyes and efective reduction clearing, fastness properties may not be satisfactory, especially during storage period of fibre/fabric, after 2-3 months. This problem is named as Thermomigration.
		Thermomigration is the movement of disperse dye from fibre/fabric into the spin-finish or finishing chemical during storage period or heat treatment.
		Thermo migration is triggered with nonionic ethylene oxide surfactants available in spin-fnish chemicals applied on dyed fibers during yarn manufacturing or in silicone softeners in stenter padders.
		During frostedor melange yarn production of dyed PES/VIS fibres, dye migrates into spin-finish chemical. After weaving, fabric is heat set in stenter and shade becomes solid. If fabric is washed at 80⁰C prior to setting, and remove the chemical, the result is encouraging. This explains that starning comes from the dye avarlable in spin finish oil.
		Same phenomena is observed on silicone finished fabrics, because silicone oil is emulsified
		by ethyleneoxide. Disperse dyes migrates into silicon finish during storage time on the shelf.
		If spin-finish or silicon softeners are selacted so that they do not contain ethylene oxide emulsifier like Unisil 2M, thermomigration problem will be out of scope.
		Unisil 2M is a ethylene oxide free silicone soften or Unisil 2M: 15-20 ml/lt whose anti yellowing rate is 4/5.
		Thermomigration in stenter is promoted between 140- 180⁰C . It is advisable to work either below 140⁰C or at 200- 210⁰C .
		What are some important points for achieving level dyeing in jet dyeing with reactive dyes.
		In jet dyeing, proper control of the exhaustion rate is achieved by,
		-Incremental dosing of salt, simply 1/10, 2/10, 7/10, each in 10 min. intervals.
		-In cheese dyeing machines or short -time dyeing cycle in jets, salt is added at once at the start of dyeing before dyestuff. In this case, isothermal dyeing program is adopted, because a higher dyeing temperature during primary exhaustion promotes the migration of dye.
		-A proper levelling or migrating time should be elapsed after salt-dye addition. 30-45 min. interval is required for proper levelling. pH of the dye bath should be around 6,5 in order to prevent fixation.
		-Dosing of alkali should be controlled very precisily, especially in first 20 min. pH should not exceed 9. So addition of soda ash as- 1/100, 1/10, 2/10. Rest at 10 min. intervals is recommendable. If pH rises very quickly, during first period, it is rather hard to improve unlevelling, especially in Blue R, Turkis G, beige, gray and khaki shades, unlevelling is unavoidable
		-Alkali should not be dosed over long period of time, because dye hydrolyzed and hence washing fastness decreases
		-Final approached pH should be around 11, if not, sodium hydroxide or liquid alkali can be supplied in the last 10 min. intervial of soda dosing period.
		-Always add soda and alkali in fresh water.
		In our dyeing plant, we have jets with different bath ratio and cırculation speed. Does it cause any problem relating my dyeing efficiency?
		Reactive dyes tend to have a low substantivity and are thus readily influenced by liquor ratio. Setting the liqour ratio as low as possible will raise the fixing rate. If the circulation rate is higher and/or liquor ratio is lower, dyestuff yield will increase and recipe will result as darker. This is the main cause of Lab/Plant variation due to low speed in lab machines.
		In order to overcome this problem and to ensure stable shade on all machines, salt amount should be decreased around 30%, in case 1/6 liquor ratio or in between. Otherwise, recipes will be darker, off-shade and poor rubbing fastness.
		I have some specks on my reactive dyed knits which are romoved ıf I rewash with acetic acid. How can I prevent the formation of these flecks.
		When the water of the dye bath contains alkali metal salts, like calcium or magnesium, there is the danger that uneven dyeing, such as specking or dystuff deposition. Aside from water, ions may come from Glauber or common salt. So addition of Antisil conz (0,5 g/lt) into the bleaching and dyeing baths enables the dyer to have trouble-free dyed fabrics.
		Antisil conz is not a simple softening agent, rather, it prevents the agglomeration of calcium and magnesium salts. Antisil keeps these ions in scatlered form and prevents them to settle on the fabric which causes speck formation. In some extreme cases, Antisil conz is advised to add into the soaping solution together with Exoline 3025, as, Exoline 3025,% 0,3-0,5
		Antisil conz,% 0,5
		In my cheese dyeing unit. I have the problem of in-out difference, tensile strength loss and softness. Although, I tried different kinds of scouring chemicals and softeners, problems are not solved satısfactorily.
		Due to high circulation power cumps in cheese dyeing machines, bobbin weights vary between 1,100-1,500 gram. Because of high density, Calcium,Magnesium, Iron, Copper ions are not removed from cotton fully, in stead, they precipitate on yarn, during bleaching process. This sedimentation reflects itself as, -Hardness -Non uniform dyeing -Tensilstrength loss. So Eksoy advise an additional deminerilization process, prior to bleaching. -Wetting-scouring agent should be also foam free and has deaerating property. If air entangled between yarn layers cannot be evacuated rapidly, foam is formed with scouring surfactant. This foam cushion is a barrier to proper flow of dye liquor and hence non uniform dyeing. Eksoy wetting agents are either low foam or foamless and all have rapid deaerating property. Prosil D Conz:Concentrated, acidic sequestering and deminerilization chemical Ewet RPN :Paste form, foam-free, wetting-scouring and degreasing agent Ewet SVS :Strong wetting and deaerating detergent, with low foam Ewet Nofoam :Concentrated, foamless wetting-scouring agent Antisil Conz :Sequestering and peroxide stabilizer Exolube NC :Levelling and dispersing chemical Ewet RPN is in paste form and is not suitable for dispenser system. A-DEMINERILIZATION Prosil D Conz,% 1,0 Ewet RPN/SVS/Nofoam,% 0,3/0,6/0,5 Temp,°C 60 Time, min. 20 Drained and without rinsing, B-BLEACHING Peroxide, %50,% 2,0 NaOH,s, % 2,0-2,5 Antisil Conz,% 1,0 Ewet RPN/SVS/Nofoam 0,3/0,6/0,5 Exolube NC,% 0,5 (If necessary) Temp, °C/Time,min 98/30, 105/20 -Hot wash -Cold wash, Neutralize and antiper with, Biokill or Perkill
		We dye cotton knitted material by exhaustion system. In the lab. wet rubbing fastness is superior to that of factory bulk production. We concluded, fastness difference and shade change comes from washing efficiency difference in lab. and bulk dyeing. Can you explain the theory behind it.
		The main cause of shade variation and poor rubbing fastness is the unsufficient washing off process in bulk dyeing. Since, laboratory washing is more effective respectively, lab. fastness (rubbing and light) are better. At the end of dyeing, three parameters are available on the fabric. Electrolyte, alkali and hydrolyzed dye. Electrolyte should be subtracted from fabric, by cold water rinsing, until concentration drops 2 Beume. If hot water used for rinsing, hue of the dye changes. If salt is not eliminated effectively, substantivity of hydrolysed dye to the fabric remains high and wash-off is rather hard. So before soaping, salt (dissolving) rinsing and neutralizing should be realized effectively. For neutralization, acetic or formic type, volatile acids are preferred. Substantivity of hydrolyzed dye to cotton is higher at cold temp, in hard or electrolyte containing water. So we recommend, thourough rinsing and neutralizing at cold temperature and -Soap, with high dispersing, sequestering property like Exoline 1025 or 3025 -Use soft salt. If salt is hard or rinsing is not sufficient, then add, Antisil Conz, 0,5%, to soaping and boiling wash liquors. Antisil Conz is a strong sequestering and dispersing agent. -Soap and Hot Wash liquors at boiling temp. Because, substantivity of hydrolyzed dye to cotton decreases at high temperature.