Updated by 21.03.2017

 OLIGOMER formation in polyester dyeing, especially in microfiber is inevitable and exist as dark

 specks on fabrics and as cloud dust on cheese dyeing.

 OLIGOMER inhibition is achieved in two steps.

  • Machine cleaning

  •  Dyeing machine should be cleaned frequently, even in light shades.

    NaOH, fl 3 - 4 g/L
    MEGACLEAR 12 1 g/L
    JETCLEAN OLG 3 - 4 g/L
    Temp., °C 135 - 140
    Time, hr 1

     JETCLEAN OLG is a catalyst for destruction of oligomer under high Ph, Foam of JETCLEAN OLG

     is not depressed at high temperature enabling the liquor to reach – contact extreme corners of

     dyeing machine.

  • Dyeing Process

  •  UNIPES COMFORT is water soluble resin which anchors on polyester fiber enhancing its

      hydrophility.COMFORT suspends oligomers in water as small molucels.

     During this process, COMFORT anchors also on oligomers and makes water soluble and drained.

    UNIPES COMFORT 1 g/L

     Please read Oligomer Prevention.

     Please read Oligomer Prevention.

     Due to its hydrophobic character of polyester fabrics and its blends are sensitive to formation of
     crease marks.
     UNIPES COMFORT is a water soluble resin which anchors on polyester fiber render it hydrophilic
     and antistatic. Formation of creases inhibited totally.

     Water is heated to 40 - 50 °C with COMFORT and the fabric is loaded. Before the initial usage of
     COMFORT, dyeing machine should be cleaned.

     Majority of pH regulating chemicals are either acetic/formic acid or their buffers. These acids are
     volatile and are transferred during dyeing to the upper gas phase leaving the dye bath as alkali.

     Alkali sensitive disperse dyes, like Blue 79, fluorescent dyes and XHF high fastness dyes are
     affected by pH Variation. In case of Lab., in dyeing tubes liquid - gas phase formation does not
     exist, because tubes are in motion, pH is stable in both phase and real recipe shade is
     approached, Exoline 3H is a nonvolatile acid based buffer and does not migrate into upper phase,
     remains in dye bath. So pH of liquor is the same as in lab.

     Due to enlargement of surface area of microfiber polyester as compared to regular polyester,
     required dye amount is doubled or tripled. Extra amount of dye is also adsorbed by PU fibers which
     impairs sublimation and washing fastness.

     We advise two successive reducing treatment.

      Acidic RC in the dye bath at 80 - 90 °C

      MEGACLEAR 4 - 11 Liquid 3 - 4
      Acetic Acid pH=4 x
      Time, min. 20

      PS/After the addition of MC 4/11,pH should be checked to 4.

      Alkali post treatment in separate bath.

      MEGACLEAR 12 1 - 2 g/L
      NaoH, fe 4 - 7 g/L
      Exolube NC 1
      Temp., °C 95
      Time, min. 20

      Hot wash and neutralize.

      Notes:

      In acid treatment, pH after the addition of MEGACLEAR 4- 11 should  be pH=4

      In alkaline clearing process pH, should end -up with

      pH= 11,5 - 12

      In finishing, silicone usage should be kept at minimum amount.

      If final treatment temp is 180 - 220 °C it is advisable to rewash at 50-60 C and dry at 130 C.

     In vinyl sulphon based dyes like, Blue 19, 21 and some Navy Blue or Blacks, adjacent polyester
     stripes are severely stained. EKSOY offers PESCLEAN 2B for this purpose.

     Prior to dyeing, fabric is washed with,

    PESCLEAN 2B 1%, 60°C, 20 min.

     And in dyeing with reactives, additionally

    PESCLEAN 2B 1%

     is supplied.

     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/L
    EXOLUBE NC 1,0 g/L
    EXOLINE 3025 2 - 3 g/L
    Liquor Ratio 1:10
    Temp.,°C 95
    Time, 60´

    Full Stripping

    MEGACLEAR 12 2 - 4 g/L
    NaOH, solid 5 g/L
    NC 1 -2 g/L
    Temp., 95 °C
    Time, 60´

     In case Turquoise HF-G, MEGACLEAR 12 and NaOH amount is increased by 30 percent.

     PS/FOR EFFECTIVE USAGE OG MC12,FİNAL PH OF STRIPPING OPERATION SHOULD BE
     BET PH=11.0-12.0.If lower add more alkali, and continue 30 min. more at 95 °C.

     a) In case of Kimsoline dyes, dye- fixing is not required, if advised dyeing processes are applied
     and thoroughly  washed by  EXOLINE MAGIC 3M or 4M.

     If fixing is necessary, COLORFIX NF 2P can be safely used with no shade change. It is formalin
     free. If has low cationic charge but with high efficiency even scarlet and red shades.

    COLORFIX NF 2P 0,5 - 1
    pH 5,5
    Temp., 50 °C
    Time 20`

     Cationic or nonionic softeners can be also given in the same bath.

     b) In case of need to strip of COLORFIX NF 2P, acidic treatment is applied

    Acetic Acid, 85% 2 - 5 ml/L
    EXOLUBE NC 2 - 3 ml/L
    Temp., 80 °C
    Time, min. 20`-30`

     In Physics, sublimation is the phase transfer, 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 150 °C , 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 leveling property

     E Type : Poor sublimation fastness but excellent leveling property.

     Sublimation fastness of polyester dying also depends on
    - Dyeing strength,
    - Reduction clearing efficiency,
    - 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 2 - 4 g/L
    NaOH, solid 5 g/L
    NC 1 -2 g/L
    Temp., 95 °C
    Time, 60´

     Even with S type dyes and effective 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 transfer 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 - finish chemicals applied on dyed fibers during yarn manufacturing or in silicone softeners in stenter padders.

     During 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 80 °C prior to setting, and remove the chemical, the result is encouraging. This explains that staining comes from the dye available 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.

     Thermo migration in stenter is promoted between 140 - 180 °C . It is advisable to work either below 140 °C or at 200 - 210 °C and wash at 50-60 Cand redry at 130 °C.

     UNISIL MCS 900, is contains 45% silicone oil with least amount of ethylene oxide based emulsifier. So thermo migration is minimal as compared to conventional silicone softeners.

     Reactive dyes tend to have a low substantively and are thus readily influenced by liquor ratio.  Setting the liquor 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 dye catalogs,salt/alkali recommendation ar advised on 1/10 bath ratio)
     In order to overcome this recipe variation 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. In low liquor ratios, alkali dosage is increased to reach  pH= 10,6 - 11. If bath ratio is over 1/10, opposite precaution is applied.

     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 Baume. If hot water used for rinsing, hue of the dye changes. If salt is not  eliminated effectively, substantively of hydrolyzed dye to the fabric remains high and wash-off is  rather hard. So before soaping, salt rinsing and  neutralizing should be realized effectively. For neutralization, acetic or formic type, volatile acids are preferred. Although, substantively of  hydrolyzed dye to cotton is higher at cold temp, in hard or electrolyte containing water we still  recommend, cold temperature  to minimize shade variation at high temp.

     - Soap, with high dispersing, dye absorption property like EXOLINE MAGIC 3M or 4M.

     - Use soft salt. If salt is hard or rinsing is not sufficient, then add, ANTISIL MA  1.0 %, to soaping and  boiling wash liquors. ANTISIL MA is a strong sequestering and dispersing agent at high pH and  temperature. It inhibits calcium crystal agglomeration which most of competitive sequstrants fail in  latter aspect. 

     - Soap and Hot Wash liquors at boiling temp. Because, substantivity of hydrolyzed dye to cotton  decreases at high temperature.

     After dyeing ,drain. (Dark Shades)

    Cold - Rinse 10 min.
    Neutralize and Soap, 80 °C, 15 min.
    Acetic Acid,pH 5-5.5 x
    EXOLINE MAGIC 4M 80 °C
    Softening

     It is due to high cationic power of yarn softener. All yarns are lubricated or waxed with paraffin after  dyeing unit, as extra coat on softeners. During washing stage, wax is locally, (partly) stripped and  some regions still remain. In stripped parts, initial high cationic softener contacts with the dye in  wash liquor and absorbs while unstripped parts do not absorb due to hydrophobic wax layer.
     Since white yarns are finished with nonionic softeners, nonionics have no affinity for anionic  hydrolysate.

     FIBERLUB K SOFT, is a low cationic power softener but has excellent friction reduction and does  not result such patch wise staining.

     In our SKY-BLUE, system, cotton bleaching started at pH= 10 and finalized at pH= 7,5 in single step.  Bleaching process is short and no more wash - off. Please, see our SKY-BLUE flyer.

     Turquoise blues are phtalocyanine based dyes with copper or nickle in the chromophore. Turquoise  blue dye molecules are double size of ordinary bifunctional dyes. So for the level dyeing, these big  molecules need high energy- that means 80 °C 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  60°C or 30 min., dye will not be fixed and will be washed off during rinsing time, hence low  repeatability and long washing period.

     As mentioned in previous paragraph, size of Turquoise dyes are rather huge and solubility in water is  low. Solubility is more reduced whenever electrolyte is added in to solution and make deposition of  dye on fabric surface spotting problem.

     PESCLEAN is very active dye dispersing and solubilizer fort this purpose. Advised amount is 07 g/L.  half in to dye dissolving tank and rest into dyeing machine.

     After bleaching, fabric is washed with PESCLEAN = 1 g/L, 60°C, 20 min. to eliminate nonionic  residue remaining from wetting agent.

     EXOLINE 4000 WEL is highly recommended for continuous and printed fabric washing.

     EXOLINE MAGIC 4M, highly recommended for exhaust washing of dyed fabrics, saving energy and  time. For dark shades,

     Calcium and magnesium salts are generated by,

     - Process water

     - Raw Cotton

     - Salt and Dye

     Majority of sequestering agents complex Ca ions at cold temperature but cannot inhibit crystal  agglomeration during scouring - bleaching, dyeing and soaping conditions, namely high temperature  and high pH. So agglomerated Ca crystals deposit on fabric / cheese surface as white specks or  cloud and lowers hydrophility locally hence unlevel dyeing.

     ANTISIL MA is terpolymer compexing agent and effective at high ph and temp with superior  dispersibility.
     We advise in scouring / bleaching and in dyeing stages as 1 per cent.
     If in soaping stage, 0,5% ANTISIL MA is added, shades become more bright.

    In cheese dyeing, you should focus on;

    Pump duration time

    In-Out 10 min.
    Neutralize and Soap, 80 °C, 15 min.
    In-Out 4 min.
    Out - In 6 min.

      Deaeration

    Air entrapped between the layers generates foam cushion with wetting and leveling surfactant based chemicals. These local cushions resist to ciculation of dye liquor and cause undyed spots.
    After loading yarn into machine, bobbins are deairated as 10 min. with


    EWET NDG 1%


    And rest of chemicals are supplied ,started with regular bleaching process.

      Low Alkali Bleaching

    In case of regular bleaching condition, high pH 11-12, detoriates cotton fiber and makes the bobbin as stiff block which is a barrier for circulation. SKYBLUE is a low pH, combined bleaching agent, Bleaching starts at 10 and ends up at 8. So yarn is soft, rinsing time is short, uniform pH through all layers, between care and periphery.

      Bath ratio variation

    If salt is added after dye dosage, bath volume is hardly controlled.
    EXOLINE FAST enables the dyer to load the salt at start of dyeing. Time is shorter and bath volume is stable. EXOLINE FAST prevents precipitation of dye particles together with electrolyte and regulates absorption speed of dye.


    EXOLINE FAST 2%

     It is not necessary by our niche chemicals.

     a)Scouring

    E WET NDG 1%
    ANTISIL MAY 1%
    Temp. 70°C, 20 min. drain, no rinse

     b)Dyeing

    ANTISIL MAY 2% (A)
    NOBLEACH 2% (A)
    Dye C
    Salt B

     Cold Rinse, 10’

     Cold Rinse, 10’ (if necessary)

     Neutralize, soap EXOLINE MAGIC 3M or 4M     1%  80°C, 20’

     Rinse 80°C

     Soften

     Softness is not the critical item for breakages. Fiber hairs on the surface of yarn creates high friction  force against smooth running of yarn and causes to split off.

     FIBERLUB K SOFT 200 is low cationic charge, lubricating softener which reduces friction force  drastically to very low levels.

     Additionally, FIBERLUB K SOFT does not absorb bleeded dye liquor during washing after knitting so  patchwise stripes do not exist.


     Untreated

     Treated

     Reactive dyes tend to have a low substantively and are thus readily influenced by liquor ratio.  Setting the liquor 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 dye catalogs,salt/alkali  recommendation ar advised on 1/10 bath ratio)

     In order to overcome this recipe variation 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. In low liquor ratios, alkali dosage is increased to reach  pH= 10,6 - 11. If bath ratio is over 1/10,opposite precaution is applied.