Fabric Production

Fabric production is one of the leading businesses in the world. Textile industries play an important role in the economy of a country. For some countries, their textile industries are one of the important sources of export and revenue generation. 

Here we will discuss how the fabric in textile industries is manufactured and the processes involved in turning cotton to a decent fabric that we wear.

 Fabric manufacturing processes

1. Singeing:

Singeing is a pretreatment process in which fabric is burned to get rid of protruding fiber ends from the surface of the fabric. If it is not done properly it can cause many problems in dyeing and printing. It can produce unclear patterns on fabric that are not desired. Moreover, if fluff is not removed properly it can be trapped in other machine-like ager and stenter and may affect their functioning. It may also affect the functioning of suction pumps installed in machines. 

Singeing machine and Singeing burner

The fabric is guided by the rollers into cloth guider which stretches the fabric thus removing the crease in the fabric. After that, the fabric enters the brushing chamber in which the rotation od brushes is against the movement of cloth. Some of the fluff is removed by brushing and a suction pump is attached which sucks the fluff and accumulate that in a bag. After that the fabric enters the singeing chamber in which fabric is burned to get rid of fluff as shown in fig 1.1. Then fabric is washed in a chemical for further de-sizing and smoothing.

The major mechanical elements in singeing machines are:

•      Rollers.

•      Bearings.

•      Valves.

•      Suction pump.

•      Cloth guider.

•      Brushes.

•      Padders.

•      Motors.

•      Belt and gear drives.

After singeing, the fabric is rolled on a roller and covered with a plastic coating. Then it is set on rotation at a speed of 20 rpm for eight hours so that the chemical applied to it can be set in completely. Fabric consists of 85% moisture after singeing, so if it is not set on rotary all the moisture will come in the lower part of the fabric which results in uneven dyeing.

2. Bleaching:

Bleaching is defined as the removal of natural coloring matter from fabric to obtain a clear and white fabric. After rotating for eight hours, the fabric is now ready for bleaching. In bleaching, the fabric is washed many times with different chemicals to obtain a bright white color. It is necessary to whiten the fabric completely in bleaching so that it can be dyed and printed correctly. If the fabric is not bleached correctly it will result in uneven dyeing and printing of fabric.                                                                                          

In bleaching fabric is washed with different chemicals like hydrogen, caustic soda, chroma bleach, chroma cast, and SPL. There are many pieces of washing in which the fabric is washed again and again with different chemicals and every time at a different temperature. After going through half of the washings the fabric is sent to a heating chamber. There the fabric remains for 15 min and comes back after drying. After that, the fabric is washed again through several pieces of washing, and at last steam, traps are used to dry the cloth. The fabric obtained after bleaching is clear white.

The major mechanical elements in bleaching machines are:

• Rollers.
• Bearings.
• Steam traps.     
• Valves.
• Pumps.
• Cloth guider.
• Padders.
• Motors.
• Belts and gear drives.
• Boeing rollers.

3. Mercerizing:

Mercerizing is a chemical treatment applied to fabrics to permanently impart a  greater affinity for dyes and various chemical finishes? Mercerizing also gives cotton cloth increased tensile strength, greater absorptive properties, and usually a high degree of luster, depending on the method used. The treatment consists of immersing the fabric in a solution of sodium hydroxide (caustic soda) for short periods of time, usually less than four minutes. The material is then treated with water or acid to neutralize the sodium hydroxide. If the material is held under tension during this stage, it is kept from shrinking appreciably; if no tension is applied, the material may shrink by as much as one-fourth. Higher-quality cotton goods are usually mercerized; cloths so treated take brighter, longer-lasting colors from less dye.

Roller driven mercerizing:

In this type, the fabric moves on the rollers and the caustic soda is showered on them through pipes. After that the fabric enters the washers where the caustic is neutralized.                                                                                                          

Chain Driven mercerizing:

In this type, a chain is used as a medium of transport for fabric. The fabric is clamped by the chain and the caustic soda is showered on the fabric. Suction pumps are also attached to dry the fabric after each wash.                                                                                                                                                             

The major mechanical elements in mercerizing machines are:

• Rollers.
• Bearings.
• Valves.
• Pumps.
• Chain.
• Cloth guider.
• Padders.
• Motors.
• Belts and gear drives.

4. Dyeing (Thermosol):

In thermosol, the fabric is dyed by using hydraulic padders. The color is applied when the fabric passes through the padders. The pressure of the hydraulic padders dyes the fabric evenly. Hydraulic padders are used rather than pneumatic because in hydraulic padders pressure is also applied to the center of padders so that the whole padder presses the cloth with the same pressure that results in even dyeing. After dyeing, the fabric becomes wet so it is dried in a heating chamber which fixes the color on the fabric.

The major mechanical elements in thermosol are:

• Rollers.
• Bearings.
• Valves.
• Pumps.
• Chain.
• Cloth guider.
• Hydraulic Padders.
• Pneumatic Padders.
• Motors.
• Belts and gear drives.

The color of the fabric is checked after dyeing a sample to ensure that after passing the fabric through pad steam or Souper it will retain the color as required by the customer. The fabric is dyed more than needed to get the required color after pad steam.

5. Pad steam:

After dyeing the fabric enters the pad steam or a Souper unit. Both pad steam and Souper performs the same function. The dyed fabric has some extra amount of color on it which comes out after washing. In industries, the fabric is passed through pad steam or Souper so that the extra color on it can be removed to keep the quality of fabric optimal.

In these machines, the fabric is passed through many washers. The fabric is washed by water many times so that the extra color on it dissolves in the water and we get the required fabric that will not lose any color after further washing. After washing the fabric is dried on the drum using steam traps.

The major mechanical elements in pad steam are:

•  Rollers.

• Bearings.

• Steam traps.

• Valves.

• Pumps.

• Cloth guider.

• Padders.

• Motors.

• Belts and gear drives.

6. Stenter:

Stenter is a machine that is used to adjust the width of the fabric. After passing through so many processes and washing several times on each process the fabric shrinks from its original size. So, the stenter is used to adjust the size of the fabric. It consists of two chains to which clips are attached which hold the fabric and move it through the machine.

The distance between the chains is lesser at the start and in the end, it is adjusted according to the required size of the fabric by the customer. There are burners inside stenter which apply heat to the fabric which helps it in expanding. The air blower and nozzles are used to send the heat to the fabric. The clips move on a fiber rail to void any rubbing due to which the clips can be damaged and cause a huge loss.

The major mechanical elements in Stenter are:

• Rollers.

• Bearings.

• Bushes.

• Valves.

• Pumps.

• Chain.

• Cloth guider.

• Burners.

• Fiber rail.

• Nozzles.

• Padders.

• Motors.

• Belts and gear drives.

The maintenance of the stenter in includes the inspection of the fiber rail, inspection of the bushes of the chain, cleaning of nozzles, greasing the gears and the chain, etc.

7. Sanforizing:

This is the finishing process. In simple words, calendaring is serving the same purpose of ironing. The fabric is passed on a pair of rollers which have steam inside them. Steam is trapped inside the rollers using steam traps. Rollers are so close to each other so that they apply pressure on the fabric and the heated heats the cloth. In this way, the fabric is ironed and becomes ready for folding.

8. Folding

This is the final step through which the fabric passes before going to the customer. In folding the fabric is folded on small rollers according to the demand of the customers. Before folding they are passed on a screen beneath which there is a tube light so that if there are any defects in the fabric, they can be identified before delivering to the customer.