What is Singeing, Definition, Types, Advantage and disadvantages of singing :

Definition:

Singeing is a process applied to both yarns and fabrics to produce an even surface by burning off projecting fibres, yarn ends, and fuzz. 

Objectives of Singing

  •  Production of smooth and clear fabric surfaces.
  •  To minimize soiling of fabric. 
  • To avoid skittery dyeing, 
  • To reduce risk of pilling specially in synthetics and blends. 
  • To enhance the quality of fabric 

Advantages of singing

  • Improved end use and wearing properties. 
  • Increased lusture (reflection of light) Less pilling Less soil attachment.
  •  Bright shades in dyed fabric.
  •  Fine intricate patterns in printed fabrics 

Disadvantages


 • Uneven singeing due to local cooling of hot metal surface 
 • Groove formation on the plate surface

Types of singeing machines

There are three main types of singeing machines: 
 • Plate singeing machine
 • Rotary-cylinder singeing machine (roller singeing machine) 
 • Gas singeing machine T

  1. Plate Singing Machine

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 redness and the cloth passes over and in contact with these plates at a speed ranging from 150 to 250 yards per minute. • The passage of the cloth can be arranged in such a manner that one or both sides of the fabric may pass over and in contact with the heated plate(s), in order to accomplish singeing of one or both sides of the fabric in a single passage. 

 Remedies 


 • In order to avoid local cooling of a certain part of the plate(s) by constant passage of cloth over it, an automatic traversing mechanism is fitted to the machine. This mechanism brings the cloth into contact with a constantly changing part of the plate(s), not only to avoid local cooling but also local wearing of the plate(s). 

    2.Rotary-Cylinder Singeing Machine 


• 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 fibres 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.

    3.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

Gas Singeing Machine Main parts 

 •  Tension unit with guide rollers and bars
 • Pre-brushing with suction 
 • Singeing chamber with exhaust Water cooled roller Ignition system Carburetor with blower Burners 
 • Post brushing with suction
 • Quenching box (desizing unit) 
 • Desizing mangleGas Singeing Machine Main parts 
 • Tension unit with guide rollers and bars 
 • Pre-brushing with suction 
 • Singeing chamber with exhaust Water cooled roller Ignition system Carburetor with blower Burners 
 • Post brushing with suction
 • Quenching box (desizing unit)
 • Desizing mangle

 Parameters of Gas Singeing Machine


1. Flame intensity
 2. Fabric speed
 3. Singeing position 
4. Distance between flame burner and fabric 
 5. Flame width Singeing parameter

Problem of Gas Singing Machine

Incomplete singeing Too low flame intensity Too fast fabric speed Too far distance between the fabric and the burner Inappropriate (i.e. less severe) singeing position Too much moisture in the fabric incoming for singeing.