Important Gas singeing parameters :

Following are the important gas singeing parameters:

• Flame intensity
• Fabric speed
• Singeing position
• Distance between flame burner and fabric
• Flame width

Flame intensity: The flame intensity of the singeing burners is based on the amount and the outlet speed of the gas-air mixture leaving the burner slots. Besides having high thermal energy, flame also has considerable mechanical energy. All the thermal and mechanical energy of the flame is directed onto the fabric during singeing. The temperature of the flame at the mouth of the burner is in the range of 1250 to 1300oC. The speed of the flame at the burner outlet may be between 15 and 35 meter per second. The flame intensity usually lies between 5 and 20 mbars.

    

      Fabric speed:The fabric speed in the singeing machine is usually in the range of 50-160 m/min depending on fabric weight (gram per square meter)  and fibre blend. For heavier fabrics, the speed is kept slower as compared to lighter weight fabrics.

     

       

F

Plate singeing: 

In this type of singeing machine, the cloth passes over and in contact with one or two heated curved copper plates. The thickness of the plates ranges from 1 to 2 inches. The heating of the plates is done by a suitable burning arrangement of gas mixed with air. The plates are heated to bright red and the cloth passes over and in contact with these plates at a speed ranging from 150 to 250 yards per minute, the protruding fibres are burnt during the passage. Due to contact between the cloth and a hard and hot surface of metal a certain amount of luster in the cloth is produced.

This types of singeing has some drawbacks as given below:

• The fibres end present in the interstices of warp and weft are not singed, since they are not made accessible. 
• As the maintenance of uniform temperature is difficult in the plates, uneven singeing may result.

This singeing process can be explained with the following figure:

Gas singeing machine: 
In this type of singeing machine, the fabric passes over a burning gas flame at such a speed that only the protruding fibres burn and the main body of the fabric is not damaged by the flame. This is the most common type of machine used for singeing fabrics as well yarns.

The line diagram is given below of gas singeing process:

Singeing: 

Singeing is a process of burning protruding fibres from a textile structure. Following figure shows the unsinged and singed yarn. In the first yarn, it is clear that there are protruding fibres on the surface of yarn and in the second yarn, the protruding fibres are removed by applying singeing process.

Similarly following two figures indicate unsinged and singed fabric.

Unsinged fabric                                                                  Singed fabric 

Singeing process brings in fabric smooth surface, less soiling and reduce pilling problems.

Singeing can be carried out using any of the following techniques:

Rotary (Roller)-cylinder singeing m/c:

In this type of singeing machine, the cloth passes over and in contact with a heated rotary cylinder made of copper or cast iron.The rotary cylinder has internal firing and revolves slowly so that constantly a fresh surface of the roller comes in contact with the cloth. The direction of rotation of the cylinder is opposite to the direction of the fabric so that the protruding fibers or nap of the fabric is raised.This type of machine is particularly suitable for the singeing of velvets and other pile fabrics. If the singeing of both sides of the fabric is required, then two cylinder are employed, one for each side of the fabric. Following line diagram shows the principle of rotary singeing: