Blow Room:

The section where the supplied compressed bale is turn into a uniform lap of particular length by opening, cleaning, blending or mixing is called blow room section. It is the first steps of spinning.

Objects of Blow Room:

(i) Opening: Further opening of compressed cotton bale and cotton are made into small tufts.

(ii) Cleaning : To eliminate dust, dirt, broken leaf, seed particles, grass and other

.foreign impurities from the fiber.

(iii) Mixing and Blending: To produce a comparatively good quality cotton fibre by rmxrng

different types of cotton together.

(iv) To produce a uniform lap of particular weight per unit length.

(v) To convert the opened and cleaned fiber into a sheet of particular width

and uniform weight per unit length is called lap.

Basic Operations Involved in the Blow Room:

(i) Opening: Opening is the first operation in the blow room carried out to the stage of flocks in the blow room and to the stage of individual fibers in the cards.

(ii) Cleaning: To remove the impurities and foreign materials and the raw material as clean as possible.

(iii) Dust Removal: To remove dust which are completely enclosed in the flocks and hence are held book during suction.

(iv) Blending: To achieve the required quality of yam by blending different qualities of cotton into a particular ratio.

(v) Even Feed of the Material: To produce a lap of uniform weight per unit length or to process the cotton fiber to the maximum optimum quality which is suitable for carding.

Name of the Experiment: Study on Color fastness to Perspiration (ISO 105 E04; 1994).
Introduction: The resistance of dyed material against various agencies in specific condition is called fastness. There is several type of fastness of dyed piece. The fastness is named after specific agency i.e. the resistance against rubbing is termed as rubbing fastness. This can be as washing fastness, water fastness, light fastness, perspiration fastness etc.
The fading of color is accompanied in hue and saturation. This is because the chemical and physical change in the bond between the dye and fiber. So the color fastness of a dyed material is a measure of its resistance to the type and extent of change of characteristic of the entire dye-fiber interaction.
Color fastness is visually assessed in respect to
1. Color change: The change in color of the specimen after exposure to specific condition is noticed. This change is normally occurred in depth of shade.
2. Color staining: During testing an undyed or multi fiber fabric is used along with the specimen to observe the transfer of color from the dyed material to adjacent multi fiber fabric. The degree of color on the undyed substrate is called color staining.
Scale for fastness grading:
In order to express the color change and color staining numerically a scale is designed to compare the degree of color change of the specimen this is called grey scale. So, there are two types of grey scale viz.
1. Grey scale for color change: These scales consist of five pairs of grey coloured material numbered from 1 to 5. Number 5 has two identical greys, number 1 grey scale shows the greatest contrast, and numbers 2, 3 and 4 have intermediate contrasts.
After appropriate treatment the specimen is compared with the original untreated material and any loss in colour is graded with reference to the grey scale. When there is no change in the colour of a test specimen it would be classified as '5'; if there is a change it is then classified with
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the number of the scale that shows the same contrast as that between the treated and untreated specimens.
2. Grey scale for color staining: A different set of grey scales is used for measuring staining. Fastness rating 5 is shown by two identical white samples (that is no staining) and rating 1 shows a white and a grey sample. The other numbers show geometrical steps of contrast between white and a series of greys.
A piece of untreated, unstained, undyed cloth is compared with the treated sample that has been in contact with the test specimen during the staining test and a numerical assessment of staining is given.
A rating of 5 means that there is no difference between the treated and untreated material. If the result is in between any two of the contrasts on the scale, a rating of, for example, 3-4 is given. Sets of grey scales, examples of which are shown in Fig. 9.1, can be supplied by the British Standards Institution.
Multifiber fabric:
Several textile fibers containing fabric used in various wet fastness test to assess the degree of color transfer from the original dyed material is called multi fiber fabric. A multifiber fabric is scoured, bleached and without any finish.
There are two types of multifibre adjacent fabric, one with wool which is type DW and one without wool which is type TV
DW: Acetate-Cotton-Polyester-Nylon-Acrylic-Wool
TV: Triacetate-Cotton-Polyester-Nylon-Acrylic-Viscose
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Principle:
The garments which come into contact with the body where perspiration is heavy may suffer serious local discoloration. This test is intended to determine the resistance of color of dyed textiles to the action of acid and alkali perspiration.
This method is intended for the determination of the resistance of the color of textiles of all kinds and in all forms to perspiration.
Apparatus and Material:
1. Perspirometer.
2. Oven, maintained at 37±2°c.
3. Multifibre (Dw) fabric.
4. Grey Scale for color changing.
5. Grey Scale for color staining.
6. Standard lighting chamber.
7. Acid and alkali solution.
8. Acrylic plates.
9. Weight 5kg.
Test Specimen:
1. Cut two identical 10cm 4cm specimens. If the fabric sample is multi-colored take as many specimens as necessary to ensure that all colors will be in contact with each of the six fibre bands of the multifibre adjacent fabric.
2. Attach the multifibre adjacent fabric of equal size to the test specimen by sewing along one of the shorter sides with the multifibre fabric in contact with face of the specimens. This is the composite test specimen.
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Reagent:
Testing condition:
1. Time of treating with perspiration solution: 30mins.
2. Temperature of heating: 37°C.
3. Time of heating: 4 hrs.
Test Procedure:
1. Wet out the composite test specimen in mentioned perspiration solution at room temperature, liquor ratio 50:1 and leave for 30 minutes.
2. Pour off excess solution and this composite test specimen between two glasses or acrylic plates under a pressure of 12.5 kPa and then place in an oven for 4 hrs at 3 2°C.
3. Remove the specimen and hang to dry in warm air not exceeding 60°C.
4. Do not press or iron the specimen or the multifibre test fabric.
Reagent
Acid
Alkali
l-Histidine mono-hydrochloride mono-hydrate (CH₉O₂N₃HCl.H₂O)
0.5
0.5
Sodium chloride (NaCl)
5
5
Sodium dihydrogen orthophosphate dehydrate (NaH₂PO₄.2H₂O)
2.5
2.2
pΗ (Adjust with 0.1N NaOH)
5.5
8
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Evaluation:
Numerically rate the color change and staining of each test specimen under standard lighting (D65, Artificial daylight) using the Grey scales for color change and color staining.
Alkaline solution:
Color change: 5
Color staining:
Acetate
Cotton
Polyester
Nylon
Acrylic
Wool
4-5
4
3-4
4-5
5
4-5
Acidic solution:
Color change: 5
Color staining:
Acetate
Cotton
Polyester
Nylon
Acrylic
Wool
5
4-5
3-4
4-5
5
4-5
Comments: color fastness color changing is Excellent but color staining is very good for acetate, good for cotton moderate for polyester, Excellent for acrylic, very good for nylon and wool.