Showing posts with label QC. Experiment. Show all posts
Showing posts with label QC. Experiment. Show all posts
7 December 2012

Colorfastness to Chlorinated Water | Color Fastness to Chlorine

Theory:
The test method by which this test is carried out is ISO 105 E03. Chlorinated Pool water fastness is getting more importance in Terry Towel industry for swimwear and also for yarn dyeing. This method is designed to evaluate the resistance to Chlorinated Pool Water of any colored textile substrate. Here, the test specimen is treated in diluted Chlorine solution under specified conditions of available chlorine content, time and pH condition.

Colorfastness to Chlorinated Water
Apparatus:
  1. Gyrowash
  2. Grey scale
  3. Color matching chamber
  4. Glass beaker
  5. Stainless steel container
  6. pH meter
Reagent:
1. Distilled water or de-ionized water.
2. NaOCl solution (100 gm/l, 50 gm/l, 20 gm/l of active chlorine at pH 7.5±0.05)

Sample Preparation:
A textile material (Dyed Goods) sample should be cut at 10 cm into 4 cm.

Procedure:

1. Put the specimen into the steel containers and added in the sodium hydrochloride solution with liquor ratio 1:100 based on the appropriate concentration of active chlorine used.
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2. Close the container and put it inti the mechanical device (Gyrowash) and agitate at 27±20C for 1 hour in darkness.
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3. Remove the specimen from the container and squeeze it.
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4. Dry the specimen by hanging it in air at room temperature in quiet light.


Evaluation:
Compare the contrast between the treated and untreated sample with Grey scales for changing color of dyed sample in a color matching cabinet. Numerical rating for color changing is the shade. 

http://textilelearner.blogspot.com/ 
18 October 2012

Fiber Fineness Measurement by Projection Microscope

The projection microscope is the standard method for measuring wool fibre diameter, and all other methods have to be checked for accuracy against it. The method is also applicable to any other fibres with a circular cross-section. The method involves preparing a microscope slide of short lengths of fibre which is then viewed using a microscope that projects an image of the fibres onto a horizontal screen for ease of measurement. The apparatus is shown diagrammatically in Fig. Techniques are followed that avoid bias and ensure a truly random sample.

Method of Test
A suitable random and representative sample is conditioned for 24 h in a standard testing atmosphere. Using a modified Hardy microtome the fibres are cut to a suitable length (0.4mm for fibres below 27 (im) and a slide is prepared by carefully mixing the fibres into the mountant. The use of short fibres gives a length-biased sample so that proportionally more of the longer fibres will have their diameter measured. The mounting agent should be non-swelling and have a suitable refractive index (for example liquid paraffin). The mixture of fibres and mountant is spread thinly on the slide and covered with a cover glass, carefully avoiding air bubbles and finger prints.
The projection microscope
The slide is placed on the stage, coverglass down (microscope inverted) and fibres are selected for measurement in the following way. The slide is traversed in a zigzag fashion, measuring every fibre that complies with the following requirements: 1 has more than half its length visible in the 7.5cm circle which is drawn in the centre of the field of view; 2 is not in contact with any other fibre at the point of measurement. The traverse of the slide is continued until the required number of fibres has been measured. The magnification of the microscope is adjusted to be 50Ox so that on the scale used to measure the fibres each millimetre represents 2 um.

For accurate tests three slides should be measured from randomly selected areas of the material and not less than 150 fibres per slide should be measured. The coefficient of variation of diameter for unblended wool lies between 20% and 28%. From this value the number of tests to give certain confidence limits has been calculated . 

http://textilelearner.blogspot.com/ 

Different Color Fastness Tests

Color Fastness:
Color fastness is one of the important factors in case of buyers demand. The outstandingly important property of a dyed material is the fastness of the shade of color. Color fastness refers to the resistance of color to fade or bleed of a dyed or printed textile materials to various types of influences e.g. water, light, rubbing, washing, perspiration etc. to which they are normally exposed in textile manufacturing and in daily use. We have written a lot of articles on color fastness. 

Color fastness test
Standards of Color Fastness:
1. AATCC (American Association of Textile Chemists and Colorists) technical manual:
Describes 66 numbers of different color fastness tests.

2. SDC (Society of Dyers and Colorists):
In 1927, SDC (Europe) made fastness test committee.

3. ISO(International Organization for Standardization):
In 1947, ISO made color sub committee. ISO also grades the fastness:
For light fastness: 1~8
For other fastness: 1~5

Factors Affecting the Color Fastness Properties:
  1. The chemical nature of the fiber. For example, cellulosic fibers dyed with reactive or vat dyes will show good fastness properties. Protein fibers dyed with acid mordant and reactive dyes will achieve good fastness properties and so on. That is to say compatibility of dye with the fiber is very important.
  2. The molecular structure (e.g.) of a dye molecule: If the dye molecule is larger in size, it will be tightly entrapped inside the inter-polymer chain space of a fiber. Thus the fastness will be better.
  3. The manner in which the dye is bonded to the fiber or the physical form present.
  4. The amount of dye present in the fiber i.e. depth of shade. A deep shade will be less fast than a pale or light shade.
  5. The presence of other chemicals in the material.
  6. The actual conditions prevailing during exposure.
You Can Read the Following Articles:
  • Color fastness to washing
  • Color fastness to water
  • Color fastness to rubbing/crocking
  • Color fastness to perspiration
  • Color fastness to light
  • Color fastness to sea water
  • Color fastness to chlorinated water
  • Color fastness to hot pressing
http://textilelearner.blogspot.com/ 
16 September 2012

Color Fastness to Wash (ISO 105 C06)

Color Fastness to Washing:
Washed sample

Color fatness to washing means, A specimen of the textile, in contact with one or two specified adjacent fabrics, is mechanically agitated under described conditions of time and temperature in a soap solution, then rinsed and dried. The change in color of the specimen and the staining of the adjacent fabric are assessed with the grey scales.

In my personal experience, in case of fastness test color fastness to washing is the first and most important requirements of buyers. There are a number of ISO test for color fastness to washing.

These are :
1. ISO test no-1
2. ISO test no-2
3. ISO test no-3
4. ISO test no-4
5. ISO test no-5
6. ISO 105 C06
  • ISO 105 C06 A2S
  • ISO 105 C06 B2S
  • ISO 105 C06 C2S
Among them ISO 105 C06 is the first choice of maximum buyers.
Now I will discuss about those fastness test.

ISO 105 C06:
Instruments:
  1. Rotawash / Gyrowash,
  2. Stainless Still Ball,
  3. Multi-fiber fabric,
  4. Grey scale,
  5. Sewing machine, 
  6. Thermometer,
  7. Color matching cabinet
Recipe:
Sodium Perborate…………..1 gm/litre
ECE Phosphate……………..4 gm/litre

Sample Preparation:
Sample Fabric………….10 cm*4 cm
Multi fiber fabric…………10 cm*4 cm

Working Procedure:

Collecting the sample from bulk and then conditioning for 04.30 to 06 hours
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Making a specimen of 04 cm*10 cm in size.
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Sewing the specimen with multi-fibre fabric of same size at one corner.
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Making the solution of 4gm/litre ECE detergent & 1 gm/litre sodium perborate, (If required SKFL use 0.15 gm/litre TAED).
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Putting the specimen with multi-fibre fabric into the solution in Rotawash m/c
Prog.: C2S Temp.: 60OC/ 40OC Time: 30 min Still ball: 25 pcs
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Rinsing with hot water respectively.
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Squeezing with cold water of the sample is done (Hand Wash).
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Then drying is done at a temperature in the air not exceeding 60OC
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The stitching is then broken out except on one of the shorter end.
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Measuring the staining and color change by grey scale & make a test report.


For ISO 105 C06 A2S:
  1. Total solution (changeable) ………150 ml
  2. Stainless Still Ball………………………..10 (for hitting)
  3. Time……………………………………………40 min
  4. Temperature………………………………400C
Everything is same.

For ISO 105 C06 B2S:
  1. Total solution (changeable) ………150 ml
  2. Stainless Still Ball………………………..25 (for hitting)
  3. Time……………………………………………40 min
  4. Temperature………………………………500C
Everything is same.

For ISO 105 C06 C2S:
  1. Total solution (changeable) ………50 ml
  2. Stainless Still Ball………………………..25 (for hitting)
  3. Time……………………………………………40 min
  4. Temperature………………………………600C
Everything is same.

http://textilelearner.blogspot.com/ 
4 September 2012

Color Fastness Test to Water ( ISO 105 EO1)

Theory:
Color fastness to water is designed to measure the resistance to water of dyed, printed, or otherwise colored textile yarns and fabrics.The test method by which this test is carried out is AATCC 107-1991 or ISO 105 E01. This method is to assess the degree of cross staining which may occur when garments are left in contact when damp. The test measures the resistance to water of any colored textiles. 

Color fastness to water
Apparatus:
  1. Perspiration Tester
  2. Oven
  3. Multi fiber fabric
  4. Grey scale
  5. Color matching cabinet
  6. Glass plate or Acrylic resin plates
  7. Weight 12.5 kPa or 5kg pressure
  8. Glass beaker
  9. Stirring rod
Reagent:
Distilled water or de-ionized water is used in this test method because natural (tap) water is variable in composition.

Sample Preparation:
Cut the specimen & multi-fibre at 10×4cm & sewn together. This is the composite test sample.

Working Procedure:

Wet in distilled water at room temperature & it will suck water.
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Place it in acrylic resin plates & put the weight on to the plates.
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Keep it in oven & keep the temperature at 37± 2°C for 4hrs.
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Open the specimen & dry it in the air hot exceeding 60°C.
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Change in color is assessed with the help of Grey Scale. 

14 July 2012

What is Drape? | Cusick Drape Test

Drape
Drape is the term used to describe the way a fabric hangs under its own weight. It has an important bearing on how good a garment looks in use. The draping qualities required from a fabric will differ completely depending on its end use, therefore a given value for drape cannot be classified as either good or bad. Knitted fabrics are relatively floppy and garments made from them will tend to follow the body contours. Woven fabrics are relatively stiff when compared with knitted fabrics so that they are used in tailored clothing where the fabric hangs away from the body and disguises its contours. Measurement of a fabric s drape is meant to assess its ability to do this and also its ability to hang in graceful curves.

Cusick Drape Test
In the drape test the specimen deforms with multi-directional curvature and consequently the results are dependent to a certain amount upon the shear properties of the fabric. The results are mainly dependent, however, on the bending stiffness of the fabric.
Drape Test
In the test a circular specimen is held concentrically between two smaller horizontal discs and is allowed to drape into folds under its own weight. A light is shone from underneath the specimen as shown in Fig. 10.4 and the shadow that the fabric casts, shown in Fig. A, is traced onto an annular piece of paper the same size as the unsupported part of the fabric specimen.

The stiffer a fabric is, the larger is the area of its shadow compared with the unsupported area of the fabric. To measure the areas involved, the whole paper ring is weighed and then the shadow part of the ring is cut away and weighed. The paper is assumed to have constant mass per unit area so that the measured mass is proportional to area. The drape coefficient can then be calculated using the following equation:

The higher the drape coefficient the stiffer is the fabric. At least two specimens should be used, the fabric being tested both ways up so that a total of six measurements are made on the same specimen. There are three diameters of specimen that can be used:

• A 24cm for limp fabrics; drape coefficient below 30% with the 30cm sample;
• B 30cm for medium fabrics;
• C 36cm for stiff fabrics; drape coefficient above 85% with the 30cm sample. 

Drape test top view of draped fabric
It is intended that a fabric should be tested initially with a 30cm size specimen in order to see which of the above categories it falls into. When test specimens of different diameter are used, the drape coefficients measured from them are not directly comparable with one another. Figure B shows a drape tester fitted with a video camera and computer for instantaneous measurement of the drape coefficient. 

http://textilelearner.blogspot.com/ 
6 June 2012

Fiber Fineness is Measured by the Airflow Method

Principle:
In this method, fiber fineness is measured by air flow. If large amount of air is blown, the fiber will be coarse and if small amount of air is blown, the fiber will be fine. The method based on this principle.

This is an indirect method of measuring fibre fineness which is based on the fact that the airflow at a given pressure difference through a uniformly distributed mass of fibres is determined by the total surface area of the fibres . 
(a)
(b)
Fig: Fiber Fineness is Measured by the Airflow Method
The surface area of a fibre (length X circumference) is proportional to its diameter but for a given weight of sample the number of fibres increases with the fibre fineness so that the specific surface area (area per unit weight) is inversely proportional to fibre diameter; Fig. shows this diagrammatically. Because the airflow varies with pressure difference it is the ratio of airflow to differential pressure that is determined by the fibre diameter. Therefore the method can be used to measure either the airflow at constant pressure or the pressure drop at constant airflow.

The measurement of airflow at constant pressure is the more usual form of apparatus with wool. For fibres of approximately circular cross-section and constant overall density such as unmedullated wool, the estimate of fineness corresponds to the average fibre diameter as determined by the projection microscope with a good degree of accuracy. 

http://textilelearner.blogspot.com/ 
5 April 2012

Color Fastness to Sea Water (ISO 105 E02)

Theory:

The test method by which this test is carried out is ISO 105 E02. This test in intended to determine the resistance of the color of dyed textiles to immersion in sea water.

Color Fastness to Sea Water
Apparatus:
  1. Perspiration Tester
  2. Oven
  3. Multi fiber fabric
  4. Grey scale
  5. Color matching cabinet
  6. Glass plate or Acrylic resin plates
  7. Weight 12.5 kPa or 5kg pressure
  8. Glass beaker
  9. Stirring rod
Reagent:

  1. Distilled water or de-ionized water
  2. NaCl (30 gm per liter)
Sample Preparation:
Cut the specimen & multi-fibre at 10×4cm & sewn together. This is the composite test sample.

Working Procedure:

Immerse each composite specimen in a separate container of the test solution at room temperature
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Agitate the test specimen to ensure through wet out
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Remove the test specimen from the test solution
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Lay the test specimen between two acrylic or glass plates and set in the perspiration tester
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Adjust the perspiration tester to produce a pressure of 12.5 kPa on the test specimen
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Place the tester into an oven and set the temperature of 37±2 0C for 4 hours
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Remove the perspiration tester from the woven
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Open out the test specimen (by breaking the stitching on all side except one of the sorter sides, if necessary) and dry the specimen in an incubator (oven) not exceeding 60 0C. 
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Change in color is assessed with the help of Grey Scale. 

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