Sunday, July 4, 2021

Testing of moisture regain and moisture content of cotton fibres

Please click on the below link to read this full article in Hindi:

फाइबर्स के मॉइस्चर रीगेन एंड मॉइस्चर कंटेंट का परीक्षण

 Testing of moisture regain and moisture content of fibres:

Moisture regain and moisture content of cotton fibres:
The percentage of water present in a material of oven-dry weight is called moisture regain. 

The percentage of water present in a material of the total weight of a material is called moisture content.

The moisture absorbed by any textile fibre depends upon the surrounding climatic conditions. If the relative humidity is high or more than standard, the fibre absorbs much moisture. If the relative humidity is lower than the standard, the fibre releases moisture in the atmosphere. The moisture regain gets very important when a yarn manufacturer purchases the fibres. If the buyer buys the fibres having more moisture in the fibres than standard then he pays money for extra moisture present in the fibres. He wastes his money for this extra moisture. 
When a textile mill purchases the fibres. They test moisture regain of fibres and extra moisture is deducted from gross invoice weight. 

Testing of moisture regain of cotton fibres:

First of all, the sampling is done according to the standard sampling method. Now the moisture regain is tested by the moisture regain tester. The whole testing procedure gets completed in the below steps. 

Structure of moisture regain tester:

In the old period, the ordinary moisture regain tester was used to check the moisture present in the fibre. Now these days, digital moisture regain tester is used. The digital moisture regain tester gives more accurate results than the ordinary moisture regain tester. The basic principle of both testers is the same. The main parts of the moisture regain tester are given below:

Drying oven: 

A heating element is fitted inside the drying chamber. This heating element is connected with the power supply. A blower fan is also mounted inside the chamber. This blower fan rotates with the help of the electric motor. A thermostat is used to control the inside temperature of the dry oven. A temperature meter is used to measure the temperature. The dry oven chamber gets closed with an airtight lid. 

Weighing scale: 

In the ordinary moisture regain tester, the one pan of physical balance gets hanged inside the dry oven. The test specimen is placed on this pan. The other pan of physical balance gets suspended outside of the drying chamber.

In the case of digital moisture regain tester, The material basket gets hanged inside the drying chamber. This material basket connected with the load cell of digital balance through the wire mounted over the drying chamber. 

Working principle of moisture regain tester:

The specimen is placed over the pan or material basket inside the drying chamber. 
The main eclectic supply is switched on now.
The initial weight of the specimen is noted. 
now the technician closes the airtight lid of the moisture regain tester.
The maximum temperature 105 plus or minus 2 degrees is prest in the temperature meter.
The electric supply of the dry oven is switched on.
The inside temperature of the drying chamber starts to increase gradually.
The moisture present in the specimen begins to evaporate now.
When the drying chamber reaches the preset value, the drying process gets stopped automatically.
Now, the oven-dry weight is noted. If we use digital moisture regain tester, the oven-dry weight of the specimen appears on the digital screen of the tester. The weight of the oven-dry specimen is found manually in the case of ordinary moisture regain tester.

Calculation of moisture regain and moisture content:

The moisture regain and moisture content of the fibres are calculated as below:

1 comment:

  1. Curing oven are excellent for high production and when components are reasonably flat and consistent in shape. They are, however, considerably more costly, and they have certain limits in terms of treating what infrared rays can readily reach or perceive. Other applications may work but will usually need testing to guarantee infrared will function effectively.


Featured Post

Simple calipers and vernier calipers, method of uses and calculations

Calipers: The calipers are very useful instruments. These instruments are used to measure the diameter of the cylinder, bore, bearing size, ...