Equipments/Instruments Used in Wet Processing/Dyeing Lab

Wet Processing Lab:
Wet processing lab plays a vital role in the quality control of wet processing department. In every wet processing lab mainly three types of tests are performed.

1. Tests for determination of the acceptability of chemicals for their intended purposes.
2. Tests for determination of several physical properties of the material.
3. Tests for determination of the quality of he finished materials.
4. Tests for determination of the quantity of dyes & chemicals required for a particular order.

When a new order is found; then the formulation of quantity of dyes & chemicals are prepared in the wet processing lab. According to the recipe at first lab dyeing is done. If the obtained shed is ok then sample dyeing is done in the floor. During sample dyeing different options are prepared by slightly altering the quantity of dyes & chemicals. The sample is sent to the buyer for approval. Buyer approves any one of the multiple options. Finally the recipe of the approved sample is taken for bulk production.

After production the bulk is tested in the wet processing lab in order to ascertain wheatear the finished products are confirming the requisite quality or not.

The instruments used in the dyeing lab are enlisted bellow with their purposes:

1. Oven:
Used for drying samples. It dries any sample by using micro wave.

2. Thermostatic Water Bath:
Used for extraction test. The samples are kept in Weing Bottle & are heated at required temperature by this instrument.

3. Tear strength tester:
Used for testing the tear strength of sample (towel). Two samples from warp & two samples from weft are tested & the average tensile strength of sample in warp & weft direction is reported separately.

4. Crock Meter:
Used for testing the rubbing fastness of sample. The sample is clipped in the sample stand & a staining fabric is clipped in the nose. Then the nose is rubbed against the sample for 10 times. At first rubbing is done in wet condition, then again rubbing is done in dry condition with another piece of staining fabric. Then the staining fabrics are assessed with standards & a grade is assigned to the sample.

5. PH Meter:
Used for testing the PH of any solution. The PH meter is calibrated at first by using standard solution. Then the sensor is dripped in to the solution that’s PH should be tested & the reading of PH is shown on the display.

6. Hot Air oven:
Used for drying sample by using hot air.

7. Absorbency Tester:
Used for testing the water absorbency of towel.

8. Color Fastness Tester:
This instrument is used for three distinct tests. These are: 
Color fastness tester
b. Color Fastness To Perspiration.
c. Phenolic Yellowing Test. This test is done in order to find out the presence of hazardous component in the poly bag.

9. Oscillating Dyeing M/C
Used for lab dyeing in exhaust process.

10. Geyser:
Used for heating water at desired temperature that is used for various tests. It is provided with separate pipes for feed & delivery of water. As it is mounted at a higher level so hot water can easily be supplied due to gravity force.

11. Horizontal Padding Mangle:
It is a lab dyeing m/c of cold pad type. In this m/c the padding rollers remain horizontally; therefore it is called Horizontal Padding Mangle. This m/c is used for sample dyeing. For dyeing any sample at first the mangle is washed with water. Then dye liquor is taken to the bath. Then towel sample passes through the liquor & then through the squeezing rollers. Then the sample is kept covered with polybag for 12 hrs. Then the liquor is drained out & the m/c is washed again with water.

12. Launder-O-Meter:
Used for assessing color fastness to non chlorine bleach.

13. AATCC Washer:
Used for washing any sample.

14. AATCC Dryer:
Used for drying samples. It dries the given sample in tumbling process in association with hot air.

15. Tensile Strength Tester:
It is used for testing the tensile strength of sample. The Grab Test Principle is used in this m/c. The m/c is provided with two jaws; one fixed (bottom jaw) & another movable (top jaw). The sample is clumped between two jaws & then the m/c is started. As the distance between two jaws increases; eventually the sample breaks. Tensile strength of the sample is shown on the digital display in kg unit. Two samples from warp & two samples from weft are tested & the average tensile strength of sample in warp & weft direction is reported separately.

16. Hardness Test Kit:
It is used for testing the degree of hardness in water.

17. Fume Hood:
This m/c has just taken in to the wet processing lab & yet it has not been erected. It is used for testing different properties of dyes & chemicals.

17. Light Box Area:
It is used for finding out deviation of shed between the batch & reference. Here a dyed sample is checked in the specific light recommended by buyer. The dyed sample is placed on the observation board that inclines at 45o angle. Then it is compared either with reference fabric or with reference pantone no. in the recommended light source visually.

The following light sources are usually recommended by the buyers:
  • D-65
  • TL-84
  • UL-35
  • UL-30
  • CWF
Except the enlisted instruments, many other simple instruments that are used in chemistry lab; are also used in wet processing lab. Those are enlisted bellow:

1. Beaker
2. Burette
3. Pipette
4. Glass Rod
5. Test Tube
6. Digital Balance etc
7. Decicator
8. Wine Bottle etc.

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Mazharul Islam Kiron is a textile consultant and researcher on online business promotion. He is working with one European textile machinery company as a country agent. He is also a contributor of Wikipedia.

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