May 1, 2023

S.D.Kiruthika

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THIES- TECHNOLOGY

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LOADING THE MACHINE Calculate chamber loading.

Loading the machine in warm water @ 50-60°C- Chamber being under loaded is a false impression- during cold rinsing fabric will increase in volume.

Fabric thoroughly wetted out by increasing the bath temperature or if necessary adding a wetting agent to the liquor, before the fabric is introduced into the machine.

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LOADING THE MACHINE DO NOT over fill the machine Especially when

processing 100% synthetic fabrics, on machines with large circular kiers because fabric will not float from centre to the front.

Consider fabric type & width of the chamber while loading.

Load- not less than 50% of nominal load- or it will lead to running problem (insufficient fabric to drive the rotor).

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CAPACITY Size of the chamber No. of chamber Construction of fabric & width Fiber to fiber blend Weight per running meter

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CALCULATING CHAMBER LOADING Rope cycle time & rope speed Maximum speed depends on machine Liquor transport system- 250 to 600 m/min Air transport system- 600 to 1000 m/min Speed depends on properties of the fabric, rope

length & rope circulation time for level dyeing. Fabric can run @ lower speed in non- critical

dyeing parts (Bleaching & After treatment) Weight per running meter = (rope weight/ Rope

length)

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S.D.KiruthikaCALCULATING CHAMBER LOADING

Rope length = (rope weight / weight per running meter)

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S.D.KiruthikaROPE CYCLE TIME & CIRCULATION SPEED

Fabric Rope cycletimes inminutes

Rope circulation speed m/min

Woven fabric Knit fabric

PES unfixedPES heat set

11-1,5

400400

250200

PA unfixedPA heat set

2-32

400350

300300

PAC 1-2 300 250Co - reactiveCo - Vat

2-31-2

350350

225-275225-275

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S.D.KiruthikaROPE LENGTH, WINCH SPEED & ROPE CIRCULATION TIME

Winch speed= (Rope length/ cycle time) No. of nozzle passages= (Process time in min/ cycle time)

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NOZZLE SIZE Based on weight per running meter Greige or raw fabric occupy ½ to ¾ of nozzle opening

For pile / terry fabrics multiply g/m by 1.3

Nozzle diameter

in mm

Weight per running metre/yard

(g/metre) (ozs/yard)

50 80 - 150 2.8 - 5.360 100 - 200 3.5 - 7.070 150 - 300 5.3 - 10.685 150 - 500 5.3 - 17.6100 400 - 700 14.1 - 24.7120 600 - 900 21.1 - 31.8

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VARIO NOZZLE

Vario nozzle- X settings

Equivalent Standard nozzle size

1 1002 903 804 705 606 50

Vario nozzle- XL settings

Equivalent Standard nozzle size

1 1202 1103 1004 855 756 65

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LIQUOR RATIO Vary based on weight, construction & quality of fabric. Include moisture content in fabric before dyeing if

fabric is already wet. There should be sufficient free liquor to feed the

pump but not excessive. MLR= Liquor in m/c (l) = 1: ……. Weight (Kg) Addition during dyeing is also considered as it

increases the volume Short liquor- increases material to liquor contact

- decreases energy, water, dyes & chemicals

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LONG LIQUOR RATIO M/CS Long horizontal dyeing m/c with long floating

action suitable for wool & polyester Do Not overload (jam) - there should be

space for fabric to float to the front of the m/c.

Nozzle gap – Polyester (lighter fabric)- 4mm - Cotton (Heavier fabric)- 5mm Over loading- needs excessive nozzle

pressure & sufficient water.

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LIQUOR VOLUME “Soft stream V” m/c- in pump running

condition- water level should be 6 inch below the top of the inner chamber dividing wall.

“Soft stream IV” m/c- half fill main chamber.

Trials should be carried out to fix optimum conditions for individual fabric.

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S.D.KiruthikaBEFORE PRE- PRODUCTION CHECK-

OIL, WAX & SPIN FINISH Leads to “unlevel dyeing” Problem in batch to batch reproducibility Higher % in 100% man made fibers- test using soxhlet

extraction

Lubricants- melting point vary- require anionic/ non-ionic scouring agent

Spin finish contains detergent- combined with detergent in treatment bath cause instant foaming- causes pump cavitation, tangling & rope stoppage.

In such case drain the machine- do not add anti foaming agent.

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Check residual oil -if 5% present, then dyes added is 5% excess- off shade, batch matching problems.

Check water after 5 min Pale/ white milky -> Safe White/ pale creamy -> drop the bath Thick creamy -> drain & refill

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AFTER PRE- PRODUCTION Wetting property- affinity for the dye

Fabric- rinse & dry- put it in water in a glass; Floating- Poor wetting property; Sink- good wetting property.

Residual size- indicator Blue spot with red rim- Polyester Blue brown with orange rim- Polyacrylate Green- Polyvinyl acrylate

pH- adjust as required H2O2 – test residual using H2O2 determination

paper

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SODIUM BICARBONATE NaHCO3 in water gives buffering effect-

water- boil 10-15 min- cool it & check pH.

pH raises- excessive NaHCO3

Use acetic acid.

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FABRIC MARKS & OXIDIZED OILS

When roll stored vertically, so stored horizontally

Oil used in knitting & weaving machine may oxidise when stored

Special scouring agents are available to remove oxidised lubricants (Hand spotting if req.)

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SPOTS OF KNITTING OIL REMOVAL Check type, amount & water solubility of knitting

oil by water or petroleum ether extraction.

@50-60°C water- add detergent/ anti crease agent/ defoaming agent/ sequestering agent or complex builder- add fabric (30 min; 60-80°C)- warm over flow rinse- drop the bath- warm rinse- cold rinse.

Demin can be done in acidic condition.

Single stage H2O2 bleaching.

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S.D.KiruthikaFABRIC FAULTS CREATED DURING DYEING Cockling:

Heat sensitive/ thermo plastic fabrics- too low speed during cooling cause Cockling.

Eliminated by large dia nozzle Increasing Liquor ratio Decreasing fabric speed

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CRACK, ROPE/ RUNNING MARKS Caused based on the material construction &

poor opening of fabric rope Avoided by pre- setting fabric

Incorrect process procedure. Increase speed & decrease rate of rise/ cooling Decrease load & increase nozzle pressure

Viscose blend- drain temperature should not be high- Shock cooling of static material will cause crack.

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Occurs in Woven Pre- setting before

dyeing Increase rope speed Increase liquor ratio

Occurs in plush & uncut pile fabric

Increase liquor ratio Reduce nozzle

pressure- better liquid circulation- Floating material transport action.

Crows feet/ wrinkling Hammer finish

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Increase fabric speed

Increase liquor ratio

Decrease rate of cooling

Woven/ warp knitted fabric- stopped during cooling stage.

Check m/c not overloaded & there is sufficient liquor in the m/c

Shock chilling may also cause this effect

Crush marks Elephant Skin/ orange peel effect

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S.D.KiruthikaFABRIC DISTORTION & INCREASE IN WIDTH Caused by too high material speed Decrease nozzle pressure Decrease winch speed

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PILLING Too high mechanical stress on fabric surface Not necessary to run @ higher speed during

scouring & rinsing Use right nozzle gap- (100mm dia, 4mm gap) For cotton/ lycra knit- (100mm dia, 6mm gap) Syncronize nozzle pressure & winch speed Set rope turnover time & winch speed then

reduce nozzle pressure

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S.D.Kiruthika Flash of Rope tangle detector light b/n winch &

nozzle gives metallic click sound. m/c will use automated/ intelligent system which is

self correcting. (or) increase nozzle pressure until sound ceases &

light no longer flashes. Use suitable chemical lubricant, check product

compatibility & anti-foaming property. Turn fabric inside out- Sometimes it may give

crease marks.

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RUNNING PROBLEMS Flat polyester filament fabrics:

Winch does not transport smoothly with required speed Increase nozzle pressure

Cotton fabrics: Winch transport rope without difficulty.

Can reduce nozzle pressure provided material circulates @ even speed.

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BALLOONING Caused by seam densely sewn, So cut 10-15

cm Vertical slit. Use chain stitch & butt seam Small ballooning reduces running marks &

gives better folding. Compromise b/n degree of ballooning & rope

circulation is necessary.

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INTENSIVE FOAMING Cause cavitation- loss of nozzle pressure &

floating of fabrics.

If foaming is less severe add de-foamer or anti foaming agent.

If foaming is severe drop the bath & restart the process with suitable anti- foaming agent.

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UN EVEN DYEING Shade variation in a rope:

Due to rapid addition of dyes & chemicals, use analogous dosing

Use glaubers salt (fewer impurities), common salt (high level of impurities) causes corrosion.

Check rope circulation time is correct. Check correct rope speed for rope length. Check motor speed synchronized.

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ROPE TO ROPE SHADE VARIATION Same rope length in each chamber Check nozzle gaps are not blocked Ensure cartridge filter sleeve sockets

correctly fitted Right quality filter fabric Same winch speed Same setting if vario nozzle is used

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BATCH TO BATCH SHADE VARIATIONS Check pH, hardness & sodium bicarbonate for

water daily. Dye affinity of fabric after scouring & bleaching

should be identical. Use same program, same liquor ratio & same

cycle time. Same rope speed based on batch size. Right chemical @ Right time & right

temperature. Different combination of dyes require different

dyeing programs

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DYE SPOTS Can be reduced by thorough mixing &

dissolving of dye stuffs @ right amount of water & @ right temperature.

Filter using fine stainless steel mesh when adding dyes to the chemical addition tank.

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S.D.KiruthikaMOTES AND PIN-HOLES

Inadequate mote removal usually results when the pH is too low during bleaching, peroxide decomposition during bleaching is high, or the motes are not adequately softened in scouring.

Pin-holes are the result of localized fiber degradation by hydrogen peroxide and is usually catalyzed by metal ions such as iron and copper.

There are many sources of these metal ions that should be checked. They may be present in the water supply.

A common source of iron is rust from water and steam supply lines. In addition, metal ions are inherently complexed with the fibers, and the amount will vary with source of fibers and/or growing conditions.