Moisture Regain and Moisture Content of Fibers

1. Introduction:

The properties of textile fibers are strongly affected by the atmospheric moisture content. Moisture and humidity influenced on the results of testing of textile materials. Many fibers, particularly the natural fibers are hygroscopic in nature and they will absorb moisture if kept in a humid atmosphere. Conversely, they will tend to lose moisture in a dry atmosphere (a process known as desorption.) Hydrophobic fibers (e.g. polyester) are those which do not absorb moisture if kept in a humid atmosphere.

Moisture regain: 
It is defined as the weight of water in a material expressed a percentage of the oven dry weight of the material.

Let, 
Oven dry weight of a material = D
Weight of water in this material = W
                                

                                    W
Moisture regain, R = …… X 100
                                   D 

Moisture content: 
Moisture content is defined as the weight of water in a material express as a percentage of the total weight of the material. 

                                       W 
Moisture content, C = ……….. X 100
                                     W+D 

Table: Moisture Regain and Moisture Content of Fibers: 

Textile Fiber	Moisture Regain (MR%)	Moisture Content (MC%)
Cotton	8.5	7.34
Jute	13.75	12.1
Viscose	11.0	9.91
Silk	11.0	9.91
Wool	16.0	13.8
Acrylic	1.5	0
Flax	12.4	10.4
Hemp	12.4	10.4
Acetate	6.0	0
Polyester	0.4	0
Nylon	4.0	3.1
Azlon	10
Metalic	0
Triacetate	3.5
Rubber	0
Wool yarn	18.25
Glass	0

2. Objectives:

1. To maintain atmospheric condition of testing laboratory 
2. To obtain good efficiency in work place
3. To know wet and dry bulb hygrometer 
4. To relative humidity is used to maintain physical properties of the fibre

3. Working Principle:   

If the bulb of thermometer is surrounded is not saturated, water evaporates from the bulb into the air at a rate which is proportional to the difference between the actual humidity since the evaporates is accompanied by cooling the temperature indicated by the thermometer will be less than room temperature.

Machine description:

This system contain two thermometer, one is dry and other is comp connected.       Distilled water stringed in this small part which is used to contain a chart by which and half of the difference of dry and wet bulb temperature. We determined the temperature.

4. Apparatus:

• Two thermos meter (dry and wet)
• Hanger
• Muslin
• Distilled water
• Water
• 0°c scale and °F scale
• Chart for relative humidity

dry and wet bulb hygrometer

5. Working procedure:

• At first we took wet bulb reading.
• Then we have to calculate the difference.
• We took reading of wet bulb and dry bulb 5 times at a internal of 15      minute.
• After getting 5 reading we calculate the average of RH% 

6. Remarks:

This one is an experiment dry and wet bulb hygrometer is way to determined quicker determination effect not eligible for testing laboratory.