90 Questions and Their Answers of Garments Washing and Dyeing

90 Questions & Their Answers of Garments Washing & Dyeing
Prepared by: Mohammad Shahadat Hossain 
Fuad Hossain
Department of Textile Engineering, 
Daffodil International University, Dhaka




1. Garment washing.
Ans: The technology which is used to modify the appearance, outlook comfort ability & fashion of the garments is called garment washing.

2. Write the purpose of washing.
Ans:
  • The first purpose is to remove dirt, dust, impurities of garments thus achieve wash look appearance and softness.
  • The other purpose is to bring faded look, old look, tinted or over dyed affect.
  • To increase color fastness, wash fastness properties no possibility of further shrinkage of wash garments.
3. Write different types of dry processing.
Ans: Sand blasting, Hand scraping, whiskering, overall wrinkle, permanent wrinkle, broken and tagging, grinding and destroy, pp spray and pp sponging .

4. Write different types of wet processing.
Ans: Normal wash / Garments wash/ Rinse wash, Pigment wash, Caustic wash, Silicon wash, Stone wash, Enzyme wash, Stone Enzyme wash, Acid wash, Bleach wash.

5. Write the machine names which are used in washing plant.
Ans: The machine names which are used in Indigo washing Ltd:

(i) Washing machine ( No of M/c -10)
(ii) Dryer machine (No of M/c -10): gas dryer-09 and Steam dryer-01

Each m/c wt: 1300 Kg
Rated voltage: 380 V
Rated input power: 6 kw

NB: these machines are imported from China manufacture: Shenzhen Multi se Industries ltd.
Bangladeshi Supplier: RM flying yang industries.

(iii) Sample Machine (No of M/c-02)
(iv) Hydro (No of M/c -03)
(v) Spray gun (No of M/c -02)

6. Write the chemical names which are used in washing Plant.
Ans:
(i) Sodium mete bi sulphite
(ii) per oxide
(iii) Caustic soda
(iv) Soda ash
(v) LV (pocket clear)
(vi) Bleach Kci
(vii) Caustic potash
(viii) Phosphoric acid
(ix) Pumice stone
(x) Optical Brightening agent (3 types: Red, blue, yellow )
(xi) Sodium hypo sulphite
(xii) Sodium bi carbonate
(xiii) Enzyme (Acid, Neutral , SL enzyme)
(xiv) Acetic acid
(xv) Softener
(xvi) Desizing agent
(xvii) Potassium per maganate
(xviii) Micro emulsion silicon
(xix) Buffer, stabilizer, fixing agent, catanizer , resin, anti staining agent
(xx) Dye for tinting or over dyeing.

7. What is the purpose of normal wash?
Ans:
  • To remove dust, dirt, oil spot, impurities, spot, size materials, starch from the garments surface
  • To bring the soft feeling to wear.
8. Describe the 1st and 2nd step of normal / garments wash.
Ans :
1st Step:-
Lot size: -....................... 80 kg Twill/Canvas garment
Add water @ L: R = 1: 8-10 ............640 --800 Liter
Machine running
Add detergent @ 0.5 gm / liter ............ 320--400 gm
Temperature..... Sometime cold & sometime 40°c - 60°c
Time .............................. 5 to 10 minutes
Drop the liquor
Cold wash

2nd Step:-
Add water @ L: R = 1: 6 ......... 480 liter.
Washing machine running
Add Flax softener @ 0.6 gm / liter .......... 288 gm.
Add Acetic Acid @ 0.5 gm / liter........... 240gm.
Time................................... 5 to 10 minutes
Drop the liquor.
Unload the Garments on trolley.

9. What is the function of Hydro extractor machine?
Ans: Function of Hydro extractor machine is to squeeze the garments for removing the excess water from the garments.

10. What is the purpose of silicon wash?
Ans: The purpose of silicon wash:
  • It gives durable softness, elastic handle,
  • It helps to anti pilling affects, dimensional stability, tear resistance.
  • It helps to fabrics to be cut and sewn more easily allows and improving wears and easy care properties.
11. Write difference between normal wash and silicon wash.
Ans

Normal wash
Silicon wash
Removes the dust, dirt , impurities, spots, size material, starch from the garments then gives soft feeling to wear
Silicon wash gives durable softness, elastic handle and helps to anti pilling affects, dimensional stability, tear resistance and  also improving wears and easy care properties.

12. Describe the Desizing process of silicon Wash.
Ans: Desizing process of silicon Wash:
Lot weight (approx 145 pies) ............ 70 kg
Add water @ L: R = 1: 10.............. 700 Liter
Machine running
Add Desizing agent @ 0.6 gm / liter ............ 420 gm
Add Detergent @ 0.5 gm / liter.................... 350 gm
Temperature.......................... 50°c
Time...............................10-20 minutes
Drop the liquor
Rinse one time 3 minutes

13. Describe the softening process of silicon Wash.
Ans:
Lot weight (approx 145 pies) ............ 70 kg
Add water @ L : R = 1 : 8 .............. 560 Liters
Add Acetic Acid @ 0.6 gm / liter ............ 336gm
Cationic Softener @ 1 gm / liter.............. 560 gm
Silicon (ME) @ 0.5 gm / liter ................ 280 gm
Temperature.......................... 40°c
Time................................ 15 to 20 minutes
Drain the bath
Then unload the garments on trolley.

14. Write the chemicals name which are used for pigment/ caustic wash process.
Ans: Caustic soda, soda ash, detergent, acetic acid, flax softener, silicon (for more soft)

15. Write the chemicals name which are used for enzyme wash.
Ans: Chemicals name which are used for enzyme wash such as Desizing agent, detergent, acetic acid, anti back staining agent , enzyme cationic softener ,bleach (Kic) , soda ash, sodium hypo sulphite.

16. Write the Desizing/ first step of caustic wash process.
Ans: 1st step of caustic wash process
Lot size: ...................... 80 kg
Add water @ L: R = 1 : 8.............. 640 Liter
Machine Running
Add Caustic soda (NAOH)..... @ 1.60 gm / liter........ 1024 gm
Add Detergent ........................ @ 0.8 gm / liter ............ 512 gm
Temperature........... 50°c to 60°c
Time (Depend upon the shade) ....... 20 to 60 minutes
Drop the liquor
Wash cold water for 3 minutes

17. What is the standard rpm of washing machine?
Ans: Standard rpm of washing machine is 28 to 30.

18. Write the chemicals name which are used for softness of garments.
Ans: Chemicals name which are used for softness of garments are flax softener, cationic softener, multi emulsion silicon.

19. Write the chemicals name which are used for good quality hand feel.
Ans: The chemical names which are used for good quality hand feel are silicon softener, flax softener.

20. What chemical use is for protect staining/bleeding on garments.
Ans: Antistatic or Anti back staining agent used for protecting staining / bleading on garments.

21. What process is doing for remove starch/sizing materials from the garments?
Ans: Desizing Process is doing for removing sizing materials from the garments.

22. Why Acetic Acid is used in Enzyme bath?
Ans: Acetic acid is used in enzyme bath to control the pH of wash bath and for proper action of enzyme. (To controlling the pH of enzyme because enzyme works at acidic pH).

23. Write different between steam dryer & gas dryer.
Ans:

Steam dryer
Gas dryer
Less temperature (60-70°c) and more time (45-60 min) required in steam dryer where it runs on steam
Comparatively more time (70-85°c) and less time (30-35min) require in gas dryer where it runs on gas.
Steam dryer is more for light Wight white readymade garments
gas dryer is more suitable for canvas/twill denim fabric
Steam dryer can give softness
gas dryer comparatively cannot give such softness

24. Describe the Desizing process of Denim Long Pant.
Ans: Batch size....................... 60 kg Denim Long Pant
Add water @ L: R = 1 : 9 .............. 540 liters
Start the machine
Temperature.................... 60°c
Add Desizing agent @ 0.6 gm / liter................. 324 gm
Add Detergent / Antistain @ 1 gm / liter ......... 540 gm
Time................................ 15 to 25 minutes
Drop the liquor
Wash first time by cold water.

25. Describe the Enzyme bath process of Denim Long Pant by Acid Enzyme.
Ans: Enzyme bath process:
Batch size....................... 60 kg Denim Long Pant
Add water @ L: R = 1: 8.............. 480 Litre
Temperature.......................... 40-50°c.
Add Acetic Acid @ 0.6 gm / litre ................288gm.
Add Anti Back staining @ 0.6 gm / litre .... 288 gm.
Add Acid Enzyme @ 2.00 gm / litre ............ 960 gm.
Time....(Depend upon the shade)...........40---60 mts.
Increase temperature to 90°c and run 1 minute (enzyme killing).
Drain the bath.
Rinse Twice, each 3 minutes.

26. Describe the Enzyme bath process of Denim Long Pant by neutral Enzyme.
Ans: Enzyme (Actual enzyme can give good effect with pumic stone)
Batch size....................... 60 kg Denim Long Pant
Add water @ L : R = 1 : 8 .............. 480 litres
Add pumic stone @ ½ vol of garments
Add Enzyme @ 1.50 gm/litre ..................... 720 Gms
Add Acetic Acid @ 0.6 gm/litre .................. 288 Gms
Add Antistain @ 0.8 gm/litre ..................... 384 Gms
Temperature......................................... 40°c to 50°c
Time (Depend upon the shade) .......... 60 to 70 minutes
Then temperature raise to 90°c for 1 minute.
Drop the liquor
Rinse Twice, each 3 minutes
Then pumic stone out from washing machine

27. How can do the killing of Enzyme in Enzyme bath?
Ans: In Enzyme bath at the end of the process temperature rise to 90°c for 1 minut to kill the enzyme.

28. Why chlorine bleach is use in Denim wet processing?
Ans: Bleaching power is used to color out from denim garments thus different of color on garments achieved i.e.; dark, medium, light.

29. What chemicals is use for neutralization of chlorine bleach?
Ans: Sodium hydro sulphite is used for neutralization of chlorine bleach.

30. Write the main 5 function of Enzyme wash.
Ans:
  • To remove the size materials from the garments
  • To remove the starch presents on the garments fabrics
  • For soft feeling to wear the garment
  • To achieve the buyer reference sample
  • To increase the color fastness & rubbing fastness
31. What is the action of Enzyme on Garments?
Ans: The action of enzyme during enzyme wash, it hydrolysis the cellulose. At first it attacks the having projecting fiber and hydrolyzed them. Then it attacks the yarn portion inside fabric and partly hydrolyzed the yarn portion and faded affect is produced.

32. What is the standard time for Bleaching in Bleaching bath of Denim Garments?
Ans: 12 to 15 minutes is the standard time for bleaching bath of Denim garments.

33. What types of Enzyme used in Bangladesh?
Ans: Mainly two types of enzyme used in Bangladesh. One is Acid Enzyme (liquid) and another is Neutral Enzyme. Neutral Enzyme is two types –

a) Powder form
b) Liquid form i.e.SL Enzyme.

34. Write different between Acid Enzyme & Neutral Enzyme.
Ans:

 Acid Enzyme
Neutral Enzyme
Acid Enzyme  is mostly used in purpose of medium and light shade
Neutral Enzyme is mostly used in purpose of dark shade and with stone for stone enzyme wash
This Enzyme affects come within short time
It affects come slowly.

35. How can control the pH value in Garments?
Ans: By using acetic acid we can control the pH value in garments.

36.What types of Enzyme suitable for Dark shade Enzyme wash of Denim Long Pant & why?
Ans: Neutral Enzyme is suitable for dark shade enzyme wash of denim long pant because this enzyme works for long time as compare to acid enzyme and affect comes slowly.

37.What type of Enzyme suitable for medium/light shade Enzyme wash of Denim skirt?
Ans: Acid enzyme is suitable for medium/light shade Enzyme wash of Denim skirt.

38.Write Desizing process of twill Long Pant for Enzyme wash.
Ans: Desizing process of twill Long Pant for Enzyme wash:
Lot weight (Approx 125 pes) ............ 60 kg
Add water @ L : R = 1 : 10 .............. 600 Litre
Machine Running
Add Desizing agent @ 0.6 gm / litre ............ 360 gm
Add Detergent @ 0.5 gm / litre.................... 300 gm
Temperature.................................... 50°c
Time........................................10---20 minute
Drop the liquor
Rinse one time 3 minutes

39.Write Enzyme bath process of Twill Long Pant Enzyme wash.
Ans: Add water @ L : R = 1 : 8 .............. 480 Litre
Temperature.......................... 45°c
Add Acetic Acid @ 0.5 gm / litre ............ 240 gm
Add Acid Enzyme @ 1.2 gm / litre ............ 576 gm
Add Anti stain @ 0.50 gm / litre ................ 240 gm
Time (Depend upon the standard)........ 30 to 60 minutes
Increase temperature to 90°c and run 1 minute.
Drain the bath
Rinse Twice, each 3 minutes.

40.Write main process of stone Enzyme wash for Denim Long Pant.
Ans: Main process of stone Enzyme wash for Denim Long Pant:
(i) Desizing/ pre- treatment
(ii) Hot wash
(iii) Stone enzyme bath
(iv) Bleaching
(v) Neutral wash
(vi) Soft wash
(vii) Hydro extractor
(viii) Dryer
(ix) Quality checking
(x) Delivery.

41.What is the perfect temperature for Acid Enzyme and neutral Enzyme?
Ans: The perfect temperature for Acid Enzyme is 45°c and perfect temperature of neutral Enzyme is 60 °c.

42.Write different types of washing faults.
Ans:
  • Color shade variation
  • Crease marks
  • After wash hole
  • Very dark and very light
  • Bleach spot
  • Bottom hem and course edge destroy
  • Running shade
  • Over blasting/low blasting
  • Over grinding/low grinding
  • Bad smell due to poor neutralization
  • Poor hand feel
  • To high hairiness
  • Poor brightness
  • High or low effect/abrasion on garments
  • Spot on garments
  • Out of range/ level of ph value of garments
43.Write the function of Anti stain, Detergent, and Potassium per Manganate, Micro Emulsion Softener, Hydrogen Peroxide, Optical Brightener, and Desizing Agent.

Ans:
  • Anti stain is used to protect staining or bleeding .
  • Detergent is used to remove dust, dirt , impurities of garments
  • Potassium per Manganate is used to color out from the garments
  • Micro Emulsion Softener gives durable softness lubricity, elastic handle, anti pilling, dimensional stability, tear resistance and fabric to be cut and sewn more easily allows and improving wear and easy care properties.
  • Hydrogen Peroxide breaks up in alkaline medium and gives some perhydroxhylion which dis color the coloring materials and as a result faddingaffect is developed
  • Optical Brightener is used to improve the brightness of garments.
  • Desizing agent is used to remove mainly starches, cmc, waxes, fats pectin’s, minerals & unfixed indigo dye from denim, twills, poplin & canvas fabrics.

44. Describe only Bleaching process of Bleach wash of Denim Long Pant.
Ans:
Batch size....................... 60 kg Denim Long Pant
Add water @ L: R = 1: 8.............. 480 litres
Machine running
Add bleaching powder (k.c.i) @ 10 gm/litre.. 4800 Gms
Add soda ash @ 5 gm/litre............................... 2400 Gms
Temperature............................................................ 60°c
Time (Depend upon the shade).................... 12 to 15 minutes
Drop the liquor
Rinse twice, each 3 minutes

45. What do you know about pumic stone?
Ans: The pumice stone are the perforated stones, produced from volcanic explosion it acts brushing action on the garments fabric surface specially on the multi layer fabric areas like –Collar, Cuff, Pocket, Placket, Side seams areas will be brushed more than the single layer areas.Pumice stones come from Indonesia and Turkey. Size small 2-3 cm, medium 3-5 cm and large size 5-7 cm. Two to Three times can be used are pumice stone. Every bag contain 22 kg to 25 kg and price 400/= to 425/=/ bag (varies).

46.Write the App. Enzyme & Silicon wash charge for Twill Men’s & Boy’s Trouser separately.
Ans: Silicon wash:
Boyes item – US $ 1.50- $1.75/Doz
Adult item – US $ 1.75- $1.75/Doz
Enzyme wash (twill ):
Boyes item – US $ 2.00- $2.25/Doz
Adult item – US $ 2.75- $3.00/Doz

47.Why we run the dryer with garment after dry 10 to 15 minutes in cold position?
Ans: we run the dryer with garment after dry 10 to 15 minutes in cold position to avoid shrinkage.

48.Which dryer is suitable to dry white readymade garments and why?
Ans: Steam dryer is more suitable to dry white readymade garments because in gas dryer flam/ burning effect can be occurred.

49.Describe the risk/problem of gas dryer.
Ans: It can create flame / burning effect on garments surface.

50. Describe the fault/problem of garments if Excess Load in the washing machine.
Ans: Washing chemicals will not work properly so desizing/fading/bleaching/softening will not achieve as required level.

51.What are the reasons of after wash hole?
Ans: Holes appearing in clothing after laundering is one of those mysteries that you will have to do a process of elimination to figure out. Look at each probable cause and then you'll need to check out and resolve each one.Using too much bleach or not allowing the bleach to thoroughly mix with water before putting in clothes will cause holes. If, however, the holes occur when no bleach is used, then this is not the cause.

52.What is the standard r.p.m(inner drum)of industrial dryer?
Ans: The standard r.p.m(inner drum)of industrial dryer is 28-30 r.p.m

53.If inner drum r.p.m of washing machine and dryer machine is too high.What types of effect on garments?
Ans: When r.p.m of washing machine is too high that time inner drum of washing machine work very quickly.So we get high quality of garments.On the other hand, when r.p.m of dryer machine is too high that time work not uniform dry. So we get low quality of garment.

54.What are std L:R for desizing,enzyme bath,softener bath?
Ans: Standard L:R for desizing is 1:9 ,for Enzyme bath= 1:8 and for Softener bath= 1:8

55.Write the name of steps of stone Enzyme wash process of Denim Long Pant.
Ans:
Steps of stone Enzyme wash process of Denim Long Pant are given bellow:
Pretreatment/ Desizing
Hot wash
Stone +Enzyme
Bleaching
Neutral wash
Soft wash
Hydro extractor machine
Drying machine
Delivery

56.Write the name of steps of Enzyme wash process of Denim Dark Enzyme wash process.
Ans:
Steps of Enzyme wash process of Denim Dark Enzyme process:
Pretreatment / Desizig
Enzyme
Softening
Hydro extractor machine
Drying machine
Deliver

57.Write the flow chart of Medium Enzyme shah wash of Denim Readymade Garments.
Ans: Pretreatment
Enzyme
Bleaching
Neutral wash
Soft wash
Hydro extractor machine
Drying machine
Delivery

58.Write the chemical name of Acid wash process.
Ans: Chemicals used in Acid wash process are-
Desizing agent
Detergent
Potassium permanganate
Sodium Matabisulphite
Phosphoric acid
Acetic acid
Softener

59.What is the standard stock solution of P.P solution?
Ans: The standard stock solution of P.P solution is 0.4% i.e. 100 Liter water 400 grams potassium permanganate.

60. How do you neutralization of P.P treatment garments?
Ans: We can neutralize the P.P treated garments by applying sodium metabisulphite.

61.Write the precaution of acid wash.
Ans:
  • Precaution of acid wash:
  • Maintain the stock solution properly constant when comes socking the stone.
  • No water licks in to the machine when treated pumic stone & garments in to the machine.
  • Not excess load the garments in the Acid wash processing.
  • Add some new stone after finishing on batch to maintain the volume for 2ndbatch. It is a matter of experience
62. What type of dyes used for Tinting of ready made garments?
Ans: Reactive Dye, Direct dye.

63. Generally which color is used for Tinting?
Ans: Orange (bright color), Yellow or Blue. Similar shade given colours.

64. Write the main tinting process (Dyeing) by Direct Dyes.
Ans:
Step 1: Desizing: Batch size: 60pcs
  • Water is added
  • Garments are loaded
  • Machine started
  • 500 gm Soda ash added
  • 500 gm Caustic soda added
  • 200 gm Bio. D added
  • Steam temp: 60°C
  • Process time: 25 minutes
  • Drop liquor
Step 2:Enzyme wash
  • Water added 400 liters
  • Machine running
  • 200 ml liquid, 400 gm powder type enzyme added
  • 150 ml Acetic acid added
  • 200 gm Anti Back staining agent added
  • 10 kg Pumice stone added
  • Temp: 50°C
  • Process time: 60 minutes
  • Drop liquor
Step 3:Bleaching
  • Add water at L:R=1:8…..480 litre
  • Machine running.
  • Add bleaching powder (k.c.i) at 10 gm/litre.. 4800 Gms.
  • Add soda ash @ 5 gm/litre ..............2400 gm
  • 50c x15-20 mts
  • Drop the liquor.
  • Rinse twice, each 3 minutes.

Step 4: Neutral Wash
  • Water is added: 400 liters
  • Machine running
  • 500 gm Hypo sulphide added
  • Steam temp: 45°
  • Process time: 10 minutes
  • Drop liquor
Step 5:Tinting
  • Water is added (400 liters)
  • Machine running
  • Add 0.02% Direct Brown GTL and 0.01% Direct Black V-200
  • 4kg salt is added
  • Steam temp: 70°C
  • Process time: 20 minutes
  • Check shad
  • Drop the liquor
Step 6: Drying

65. Write the main tinting process (Dyeing) by Reactive Dyes.
Ans:

Step 1: Desizing: Batch size: 60pcs
  • Water is added
  • Garments are loaded
  • Machine started
  • 500 gm Soda ash added
  • 500 gm Caustic soda added
  • 200 gm Bio. D added
  • Steam temp: 60°C
  • Process time: 25 minutes
  • Drop liquor
Step 2: Enzyme wash:
  • Water added 400 liters
  • Machine running
  • 200 ml liquid, 400 gm powder type enzyme added
  • 150 ml Acetic acid added
  • 200 gm Anti Back staining agent added
  • 10 kg Pumice stone added
  • Temp: 50°C
  • Process time: 60 minutes
  • Drop liquor
Step 3:Bleaching
  • Add water at L:R=1:8…..480 litre
  • Machine running.
  • Add bleaching powder (k.c.i) at 10 gm/litre.. 4800 Gms.
  • Add soda ash @ 5 gm/litre ..............2400 gm
  • 50cx15-20 mts
  • Drop the liquor.
  • Rinse twice, each 3 minutes.
Step 4: Neutralwash
  • Water is added: 400 liters
  • Machine running
  • 500 gm Hypo sulphide added
  • Steam temp: 45°C
  • Process time: 10 minutes
  • Drop liquor
Step 5: Tinting
  • Water is added (400 liters)
  • Machine running
  • Add 0.03% Reactive MPL and 0.02% Reactive 300pp
  • Added
  • 4kg salt is added
  • Steam temp: 70°C
  • Process time: 20 minutes
  • Check shade
  • Drop the liquor
Step 6: Drying

66. What is Standard Blowing angle for Sand Blasting?
Ans: 200

67. What are the main ingredients for Sand Blasting process?
Ans: ALUMINIUM OXIDE (Al2O3)

68. Write the approx. Production/hr/gun of sand Blasting.
Ans: 25-50 garments (depends on rate of fading needed)

69. Write the name of protective items for health in the sand blasting process.
Ans:
  • Mask
  • Hand gloves
  • Sound protector
  • Cap
  • Safety Glass
  • Apron
70. What do you mean by PP Spray?
Ans:
  • By spray gun potassium permanganate is sprayed on garments surface.
  • Chemical composition: 10g kmno4 in 1 litresoln with 1% lubricant.
  • After desizing pp is done then neutralized by oxalic acid.
  • Very much body hazard.
  • High production rate.
71. What do you mean by PP Sponging?
Ans:
  • Buyer recommended PP Sponging avoiding pp spray
  • But manufacturer ignored it because PP sponging has low production
  • Manually by sponge potassium permanganate is get touched with garments before main enzyme wash and after desizing and hot wash.
72. What is the purpose of PP Spray?
Ans:
To import smogyfaded effect in garments.

73. What is the purpose of PP Sponging?
Ans:
To import fading effect in specific areas (thigh,bum,knee) of garments as buyer recommended.

74. What do you mean by Whiskering?
Ans:
  • It is known as CAT’s whisker,Moustache,Honeycomb.
  • It’s another form that shows a worn effect but fashionable garments.
  • Steps of Whiskering:
  • Plot the design (buyer) on a tracing paper
  • Transfer the design on ply wood
  • Place the rubber sheet on ply wood as the design on ply wood
  • Attach rubber with wood by gum to make the pattern
  • Enter the pattern in front opening of pant
  • Rub by emery paper (300,400,500) ppm
  • Thus the effect comes on garments is called “WHISKERING”
75. What do you mean by Tagging?
Ans: Tagging is a washing process by which crease marks is occurred in the upper portion of garments and dark shade is occurred inside of tagging. This process is done by using tagging machine or also by needle and thread & manually.

76. What do you mean by Grinding?
Ans: Grinding is doing on garments for mainly old/used look appearance & fashion. Grinding is doing on hem, pocket edge, waist belt, pocket opening & pocket pluff of garments. This process is done by using grinding machine or sand paper by manually.

77. What do you mean by Destroy?
Ans: Destroy is doing by manually or different types of machine used for destroying the garments: grinding machine, emery cloth, hacksaw blade, knife etc.when destroy is done on garments, it seems to be long time use effect.

78. What types of fabrics are suitable for Permanent Crinkle?
Ans: Dense woven fabrics normally (twill like DENIM, plain like BABY FROK), Single jersey ( rare case )

79. Write the chemical name for permanent Crinkle on the Garment.
Ans:
I. Stock solutions for Resin solution is 300g resin in 700L water.
II. Wetting agent : 0.5% owf
III. Resin : 6-10% owf
IV. Softener : 3-5% owf
V. Water : 60-80 litres

80. What is the standard Temperature for permanent Crinkle on the oven?
Ans: 140c to 160c

81. What is the standard time is required for permanent wrinkle in the oven?
Ans:
Time:20-40 minutes,15 minutes(Standard)

82. What do you mean by overall Crinkle?
Ans:Which type of crinkle is created through the hole garments but not permanently placed, that is called overall crinkle.Basis on area of crinkle the overall crinkle is determined.Overall crinkle is done in :Mens shirt-pant, Women tops etc.

83. What types of Dyes are used for 100% cotton readymade Garments?
Ans:
  • Vat dye(high cost, excellent fastnes)
  • Reactive dye(less cost. Good fastness)
  • Indigo dye (better rubbing fastness)
  • Disperse dye
  • Sulphur dye
84. What do you mean by Ready for Dyeing Garments?
Ans:
  • RDG means which garments already desized,scoured,bleached.
  • Its colour is white. It is clean and ready to treat with dye.
85. Write the main/first step of ready for dyeing process.
Ans:
Good pretreatment (DESIZING)

86. What do you mean by super white process?
Ans:
Which washing process creates white garments made of cotton grey fabrics is called super white process, it just severly washed out the colour of garments by extreme bleach action then brightening the garments.

87. Write the chemical names which are used for super white process.
Ans:
  • Detergent
  • Caustic soda(COLD)
  • Soda ash
  • Hydrogen per oxide
  • Stabilizer
  • Acetic acid
  • Optical brightener agent
88. Write the Dyeing bath process of Pigment Dyes for cotton ready-made Garment.
Ans:
Pigment dyes are useful to give a washdown casual look on leisurewear. These dyes are less precise than reactive dyes as colour matching cannot be so precisely achieved. This is because the process involves 3 main stages. The first stage is to treat the fabric with a cationic product. This in effect makes the fabric more readily accept pigment dye molecules that do not really penetrate the fibres as other dye types but tend to sit on the surface of the fabric. This quality is how the washdown look is reached in the second stage.

The second stage is applying the pigment dye. With the machine turning quite quickly the pigment dye in liquid form, rather like paint, is introduced into the machine and is dispersed over the fabric. The machine turns quickly to ensure an even dispersal. During this part of the process the mechanical action of the machine and the fabrics rubbing on each other knocks off some of the dye. The dye is reduced particularly from the high spots such as seams, hems pocket edges and so forth. There is no separate washdown process as this dye cycle is usually sufficient to achieve the required look. As the dye only sits on the surface removing some of it by mechanical action reveals the undyed fibre. This gives the worn look associated with pigment dyes.

The third stage involves processing with a binder. This is designed to keep the pigment dye attached to the surface of the fabric. Of course there are various rinse stages between the main processes and the final stage is usually a softening bath.

89. Write the Dyeing bath process of Sulphur Dyes for cotton Readymade Garment?
Ans:
Sulphur dyes and find their main use in the dyeing of cellulosics and their blends. They are insoluble in water but can be converted into their leuco form using a reducing agent like sodium sulphide, in which state they have a high affinity for the fibre.

Sulfast dyes exhibit good all round fastness properties except for hypochlorite bleaching.
General Application Methods:Sulfast dyes can be applied in the following ways:
  1. Jigger Dyeing - Batch wise.
  2. Drum Dyeing - Garments.
  3. Warp – sheet dyeing - Denim.
Solfast dyes are water-soluble dyes but having no substantivity. Hence can be applied by the pigmenting system to allow the dye to fully penetrate the substrate by padding(as in the case of woven fabrics) or by package dyeing (as in the case of yarn) and then reduced at a later stage.
This helps to ensure better penetration and level dyeing
  • Package (Cone or Cheese) Dyeing.
  • Pad – Steam
  • Pad – Batch
  • Pad – Dry – Chemical Pad.
  • Warp – Sheet dyeing.

90. Write difference between Sand Blasting and Hands Scraping?
Ans:
Sand blasting is done on the garments by using the nozzles to apply sand(Al2O3) flow to get faded effect otherwise hand scrapping is done on the garments surface manually by using scrapping paper to get the faded effect. Sand blasting is hazardous for health otherwise hand scrapping is not.

References:
  1. Textile bloggers.com/important questions of Md. Golam Faruk
  2. Lab activities on Indigo washing Ltd,Station road,gazipur
  3. Books of washing technology & many other website related to Garments Technology. 
 
Published by


Mohammad Shahadat Hossain
Department of Textile Enginnering

Daffodil International University, Dhaka, Bangladesh
Contact: +8801934386724
E mail: shahadat1859@yahoo.com 
 
 
 
 

1 comments:

Anonymous said...

please also mention the function of the chemicals used like detergent caustic softeners

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