Singeing Process in Textile Industry: Machine Types & Advantages

Singeing is a fundamental pre-treatment process in textile manufacturing, especially for natural and cellulosic fabrics. In this article I will explain overview of singeing process in textile industry, its objectives, types of machines, working principles, advantages, disadvantages, and overall importance in fabric quality improvement.

Singeing Process in Textile Industry

Protruding fibers are formed during fiber production. This protruding fiber make the fiber faulty. These loose fibers mainly come from short staple fibers, imperfect spinning, or mechanical abrasion during weaving and knitting. We use singeing to remove the faults from the fabric. At first, we need to know what is singeing? Singe refers to burn superficially, we can say that singeing is the process that burning off the protruding fiber or yarn from the fabric surface by controlled heat without affecting the main fabric structure.

Objectives of Singeing

1. Remove the hairiness
2. Reduce pill formation by eliminating loose fiber ends that initiate pilling during wear and washing
3. Prepare the fabric suitable for the subsequent process (dyeing, printing, finishing) by ensuring uniform chemical penetration and even coloration
4. Improve luster and smoothness by creating a clean and even surface
5. To get good hand-feel etc. and improve overall fabric appearance and quality

Types of Singeing

Based on the machine, we get three types of singeing process

1. Hot plate singeing machine / copper plate singeing machine
2. Roller singeing machine /rotary cylinder singeing machine
3. Gas singeing machine

A. Plate Singeing

In this process, consist two copper plate and thickness of these plate is 1”-2”. Copper is used because of its high thermal conductivity and ability to provide uniform heat. The plate is heated from the opposite direction by the using combination of gas and air with suitable arrangement. The temperature reaches up to 150°C depending on fabric type and machine setting suitable arrangement and it’s become bright red.

Working Principle of Plate Singeing Machine

With the help of guide roller, the fabric passes over the hot metallic copper plate at the speed of 150-250 yards per minute. Lower speeds are used for delicate fabrics, while higher speeds suit heavier constructions. The speed of the fabric depends on the arrangement of copper plate and quality of the fabric. The fabric make contact with the copper plate while it’s passing over. Due to contact of the plate, the protruding fiber is burn off but there will be no damage to the fiber if temperature and contact time are properly controlled. As the protruding fiber burns, the fiber will be more lustrous. Also, the fiber gets soft hand feel, smoothness and many good appearances which is especially important for high-quality woven fabrics. At the end of the process, the singed fabric passes through the water bath to extinguish the spark with the help of guide roller and to prevent after-burning.

Advantages of Plate Singeing Machine

• Uniform singeing
• Improve luster
• Remove hairiness from the surface of the fabric and improve smoothness
• More effective for velvet and pine fabric where controlled surface treatment is required
• Machine set-up is easy

Disadvantages of Plate Singeing Machine

• Only one side of the fabric can be singed
• Difficult to control the heat of the plate
• It is a discontinuous process
• Time consuming process
• Sometimes it’s decreased the strength of the fabric due to excessive heat exposure
• Need to clean the plate after a few uses.

B. Roller Singeing

Roller singeing process is like as plate singeing process but the difference between two process, we used copper plate in plate singeing machine which can’t rotate but in roller singeing process, use a roller (hallow cylinder) which fired by internally and rotate slowly in opposite direction to the fabric to ensure continuous surface contact.

Working Principle of Roller Singeing Machine

With the help of the guide roller, the fabric gets proper tension and passes over the hollow cylinder which rotate from the opposite direction of the fabric. The fabric passes at the speed of 135-225 meters per minute according to fabric quality and arrangement of machine. Speed regulation is critical to avoid scorching or under-singeing. A powerful squeezer nip regulates the speed of the fabric. When the fabric passes over the cylinder, it’s contact with the surface of the cylinder and protruding fiber will burn off without any damaging of the fabric when uniform heating is maintained. After completing the process, the fabric passes through water bath to quench sparks and cool the fabric.

Advantages of Roller Singeing Machine

• More uniform singeing than plate singeing
• Increase luster and smoothness
• Remove hairiness

Disadvantages of Roller Singeing Machine

• Only one side of the fabric can be singed
• After few uses, need to clean the roller
• Too fast or slow speed may be the reason of damaging fabric due to uneven heat exposure.

C. Gas Singeing

The gas singeing is more popular and widely used in our textile industry. It is a continuous process. The machine consists two sets of gas burner. Natural gas or LPG is commonly used as fuel. Fabric passes over the gas burners with the speed of 50-180 meters per minute. The speed of the fabric depends on fabric quality and arrangement of gas burners also depends on flame intensity, flame position, etc.

Working Principle of Gas Singeing Machine

With the help of guide ruler, the fabric passes over the brush which rotate from opposite direction of fabric and the protruding fiber will stands on the surface. Brushing ensures fibers are upright for effective burning. When the fabric pass through the gas flame, the straight and stands protruding fiber burns off. Similarly, the fabric passes through the second burner and singed another side of the fabric. In this way both side of the fabric will be signed with the help of large number of guide roller. There is a suction hood each of the burner. Main function of suction hood is releasing dust and fluff which produce in burning chamber and maintaining a clean and safe working environment. After completing the process, the fabric passes through the water bath to extinguish spark and then a squeezing roller squeeze the fabric to remove excess water.

Advantages of Gas Singeing Machine

• Both side of the fabric can be singed
• Easy to control uniform temperature
• Uniform singeing
• Continuous process, so no hamper in production
• Less time-consuming process

Disadvantages of Gas Singeing Machine

• Dirty burner can damage the fabric
• Not suitable for synthetic fabric as thermoplastic fibers may melt instead of burning
• Fabric may be burnt for in consistence of fabric speed
• High initial cost
• Need more space for machine setup.

Conclusion

Singeing is very important pre-treatment process for natural fabric or yarn in our textile industry. It is especially important for cotton, linen, and other cellulosic fabrics. It removes hairiness or protruding fiber and make the fabric suitable for next process. Without singeing, subsequent process may be faulty like uneven shading, pilling etc. Singeing improve the quality of the fabric.

You may also like: Cost Calculation in Singeing Process

References

[1] Hossain, Md. Imranul, Singeing Process: Objectives, Methods, Advantages & Disadvantages, Textile Blog, https://www.textileblog.com/singeing-process-objectives-methods-advantages

[2] Singeing Fundamentals” ByDr. Tanveer Hussain

[3] General knowledge in Textiles and Garments” by Dr. M A Sayed.

[4] Textile pretreatment by Muhammad Moosa AR Khan, SDC Muhammad Awais Imran, SDC BS, MS Textiles, IRCIndus University, Pakistan

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