Yarn to Fabric Manufacturing
A case study on spun yarn production to fabrics and finishing processes in a real-time production environment
A Yarn is usually of substantial length & of a small cross-section. In the cross-section of yarn, there are usually multiple numbers of Staple fibers (short fibers) or Filaments (long fibers) of unlimited length.
Spinning is the process of creating yarn (or thread, rope, cable) from various raw fiber materials. Several fibers are twisted together to bind them into strong, long yarn. Characteristics of the yarn vary based on the material used, fiber length and alignment, quantity of fiber used, and degree of twist. The earliest spinning probably involved simply twisting the fibers in the hand. Later the use of a stick to help twist the fiber was introduced.
When various fibers of different or same grades are kept together and mixed in a specific ratio, it is termed blending. Blending is based on the movement of important fiber properties like length, fineness, strength, etc., and quantitatively proportioning and combining under controlled conditions.
- It is done to improve texture, reduce cost, and increase workability.
- In OCM, wool fibers are being mixed with other fibers such as polyester, viscose according to the requirement of order or for the company. Threemachinesareusedone after the other to make a better fiber.
This is a process where the yarn will be straightened again so that they are arranged in a parallel manner. While at the same time, the remaining short fiber will be eliminated completely from the longer staple fiber. By doing this, long-staple will produce a stronger and smoother fabric which is highly demanded in the market.
- The machine used in the industry is PV –31NSC
- Only one machine is installed
Thecombedfibresarethensenttothegillboxmachine.Itstrengthensthefabricbythoroughly ginning the slivers. it works as an auto leveler also, which means giving it a constant weight to length ratio.
- Machine used –GC143
- Total two machines are installed.
At this stage, it will be pulled the sliver lengthwise direction over each other. Thus, it will cause it to be stronger and thinner in production which is very important in the evenness of the yarn. If there are any faults occur during the process, they will still pass into the yarn.
Most manufacturers will use a blending process where two or more different types of fibers will be blended to form a yarn. The common type of blend used is the Cotton/Polyester combination, doing this will not only reduce the cost but also increase the performance. The machines installed in this process are four with a different number of heads. Two machines are of one head, one machine is of two heads, and the last machine is of three heads.
- Machine used isGC143
This is the final stage where the preparatory steps for insertion of the twist. Enough twist is given to hold the fibers together but still has no tensile strength. The roving in bobbins is placed in a spinning frame where it passes several sets of rollers that run at high-speed to convert into yarn forms.
|1||Machine used||FM7 NSC|
|2||No. of machines installed||5|
|3||No. of spindles per machine||20|
The yarn produced is processed into a speed frame to attain roving yarn. This is the initial step where a twist is inserted for giving hold to the fibers in a spinning mill. The roving yarn is of a little larger diameter as compared to the final yarn. Similarly, ring frames are used to produce finished yarns from obtained roving yarns. Yarn is resulted in having a good amount of strength through these ring frames.
|3||No. of spindles in on machine||556|
|4||The output of one machine||50 kg|
Functions of ring frame:
- Draft the roving until the required fineness is
- Twist the drafted strand to form yarn of required count and strength.
- Winding the twisted yarn onto the bobbin for suitable storage, transportation, and further processing.
After the ring frame section, bobbins are sent to the autoconer section where it is converted from a small package to a big standard package. If there is any fault at any section, only that particular section stops not the whole machine. A blower is used to clean the machine side by side which removes short fibers.
After manufacturing of yarn, from different departments in the preparatory process and ring department, it is ready to make a shape into final cone form so that it can be shipped to the customer for use. During the winding process of yarn, the following objectives are met.
After winding, cones are taken for the heat-setting process. There is a pressure chamber that is used to sterilize equipment and supplies. When cones are placed inside the autoclave, they are exposed to high-temperature steam. Thisprocessisdoneto avoids the snarling and shrinkage effect which generally comes after giving twists to the yarns which were being wound in cones. It can be done at any stage of winding.
|1||The temperature of the steamer||85 ℃|
|2||The pressure of the steamer||6kg/sq. cm|
|3||Time taken||2 hours|
|4||The capacity of the machine||300kg – 400kg|
After the auto winding process, yarns are twisted again in which two cones are being used to make one final cone. The purpose of producing doubled yarns is to improve yarn uniformity and increase strength. This is also an essential process to produce balanced yarn.
It is a two-stage process:
- Doubling–Thisprocessiscalled is doubling.
- Twisting – Z twist is given to the yarn while winding it on the final cone.
|1||Total no. of machines installed||6|
|2||No. of heads in one machine||120|
|3||Time required for winding a cone of 24 count||30 mins|
|4||Time required for winding a cone of 80-90 count||7.5 hours|
|5||Weight of one all wool cone||980g|
|6||Weight of one terry wool cone||1kg|