Singeing

Textile Engineering

1. Fabric Singeing Machines

2. Machines for singeing  Rotary cylinder singeing machine   Plate singeing machine Gas singeing  machine

3. Plate singing machines operations In plate singeing the fabric is pass over one or two curved plates of cupper with size 1”-2” thickness.  Guide rollers are used to ensure the enough contact of cloth with the plate surface so that the projecting fibers are removed without any damage.

4. Fig: Plate singeing machine Parameters of singeing machines: 1 .  The plates are heated up to 150 °C. 2.  Speed of the cloth is 135 to 225 meters per minute.

5. Roller singeing machine operations 1. In roller singeing machine fabric is passed over a hallow cylinder of copper or cast iron cylinder which is heated by internal firing. 2 . The cylinder revolves slowly opposite to fabric direction. 3.  The face and back surface of the fabric may be singed in single passage by using two rollers.

6. Parameters of Flame singeing Machine: 1. Composition of flame   -1 part LPG (liquid petroleum gas) -2 parts Air  2.  Nature of flame -Use oxidizing flame because it produces minimum amount of ash.   -Temperature of the flame is about 1300°C. 3.  Distance of flame from fabric surface should be 1.5 to 4 mm . 4. Speed of the fabric   -Speed of the fabric depends upon quality of the fabric -Speed of low quality fabric should be 120 meter per minute.   -Speed of High quality fabric should be 60 to 80 meter per minute. 5 .  Angle of the flame -Perpendicular to fabric structure(for heavy weight fabric) -Tangential to fabric structure(for light weight fabric)

7. Zones of Gas Singeing Machine There are five zones of singeing Machine Entrance Zone Brushing Zone Singeing Zone Washing Zone

8. Gas Singeing Machine

9. Gas flame singeing m/c This is the most commonly used process for woven fabric. In gas singeing machine both side of the fabric can be singed in same time. Normally two burner are used for both side singed. In this machine the fabrics are passed through some guide roller over the gas burner in open width as shown in the figure. The length of the burner can be adjusted according to the width of the fabric. The fabric passes over the burner at the speed of 200-400 yard/min. When the fabric passes over the burner, it burns the projecting fiber from the surface of the fabric. Brush is used for brushing the both sides of the fabric. After singeing, the fabric is immersed in the water or desizing tank to prepare next process.  

10. INDIRECT systems Thermal energy produced by the source is used for burning the fibers and there is no contact between the heat source and fabric. Example– Radiation Singeing. Here fire-proof ceramic blocks are heated to a high temperature, which radiate infrared radiation. This radiation can heat the fibers to such an extent that they can burn . The advantage of indirect singeing are : No Flame Contact, hence safer approach Uniform Singeing, as radiation can be distributed uniformly around a fabric surface.

11. Problems in Gas Singing 1) Uneven singeing -------------->can lead to dyeing Streak 2) Thermal Damage --------------> due to high flame temperature 3) Stop Offs --------------> whenever the machine stops, excessive localized heating may result in Heat Bars 4) Creasing --------------> Dyeing Streaks 5) Size Hardening --------------> Difficulty in desizing

12. Yarn Singeing

13. Yarn Singeing Textile yarns are singed for applications like sewing thread, where the resistance caused by protruding fibers during high speed sewing needs to be lowered. The high friction may lead to a lot of frictional heat generation, leading to damage to fabric and frequent yarn breakage.

14. Yarn Singeing Yarn Singeing machines are required to prepare bright and lustrous yarn with smooth surface as in case of sewing and embroidery threads. A hairy and a singed yarn

15. Yarn Singeing The machine consists of a number of suitably sized gas jet burners equal to the number of package to be handled by the machine. The yarn passing from a big package is allowed to meet jet burners and the singed yarn is rewound on a smaller package. Nowadays electrical burners heated to about 1,100°C are used for the purpose of assuring greater safety.

16. Nowadays electrical burners heated to about 1,100°C are used for the purpose of assuring greater safety.

17. Yarn Singeing m/c

18. Bio-polishing Removal of surface fibers by the action of enzyme. Enzymes used for bio-polishing are named as cellulase .

19. Testing singeing effectiveness The effectiveness of singeing process can be checked by one or more of the following: By looking at the singed fabric with magnifying glass and comparing its hairiness with that of the un-singed fabric. A well-singed fabric shows less hairiness. By testing the singed fabric for pilling performance and comparing it with that of the un-singed fabric. A well-singed fabric gives less pilling.

20. Pill formation

21. Testing singeing effectiveness By sticking and removing a sticking tape on the singed fabric and observing the number of fibers attached to the sticking side of the tape. A well-singed fabric results in less number of fibers sticking on the tape.