In winding to get a continuous length of yarn, the yarn from the spinning cops are joined or combined together. So it is necessary to join or piece two ends of the yarn. Here joining is done by putting a knot. Knot could be put or performed by both manually and with the help of machine by using mechanical knotters.
If a knot is put manually then it will be bigger in size and it will be serious in weaving. These big knots will not through the reed wires in the loom. In knitting process, these big knots will not pass through the needles. To avoid these faults and defects mechanical knotters are provided.
Out of different types of the knot, the most popular and the most widely used knots are weaver’s knot and fisherman’s knot. Depending upon the type of fiber used to make the yarn the knots are being used.
For example, weaver knots are used for cotton yarn. In the case of synthetic yarns the weaver knot will slip hence it could not be used, so the fisherman knots are preferred for the synthetic blend. The best knot is said to be the one which gives the least slippage and end breakage under working condition.
The above knots could be made manually but if done manually then the tail ends will be longer. So the knotters are used by the workers in the high-speed winding machine. In the automatic winding machine, there is a knotter head which is used to suck ends from supply and delivery packages and the knotting is performed between these two packages.
In high-speed winding machine after the knots are put the extra tail ends are sheared by shearers. Hence here there are very fewer chances of getting big knots and the yarns will be superior in quality.
Knotting is also carried when the end breakage occurs. In high-speed winding, a broken thread stop-motion wire works and the is being lifted from the surface of the drum. The worker will be coming to the drum unit and takes the end from the cone and then from cop.
Then he puts the knot with the help of mechanical knotter. In case of automatic winding machines, the knotters consists of two clamps, in which one clamp will suck end from the cone and the other clamp sucks the ends from cop and knotting is being performed mechanically. In the automatic winders, separate attachments are necessary for putting fisherman knot and weaver knot.
Splice has the same function as a knot. Splicing is said to be the new technique for piecing up the broken ends. Here joining of two ends is done by air or some other mediums. Splicing is used in the Schlafhorst type of auto coner. Usually, there are two methods of splicing. They are said to be wet splicing and air splicing.
Wet splicing is carried out manually with the help of manpower by the winders. A simple trough containing water is provided for each winder which is hanging from the winder neck by a small cord.
In this method the two cut or broken ends are overlapped with each other and water is applied to them. In some machine, it is done manually and in the rest, it is done automatically by using the water jet principle. Comparing with air splicing this method is being used less.
As the name indicates in this method the piecing is done by using air. In this splicing, there are two stages. The first stage is said to be the one in which in which the two broken ends are passed through suction holes provided in the splicing unit. Further, the broken ends are untwisted and the fibers are now free.
Now the second stage begins, the broken ends are placed and are overlapped in an inclined slot which is provided in the intermingling chamber for this purpose in the splicing unit. After overlapping the ends, in the intermingling chamber, the joining process is achieved by the combination of vertical and tangential jets of air acting on the fibers , with the continuous rotary movement of the air by passing a jet of compressed of air.
Advantages Of Splicing
- There is no tail ends as in knotting hence shearers are not necessary.
- The yarn produced is even.
- Weaving performance is improved as the yarn will pass through the reed wires easily.
- The fabrics which are produced by using spliced will have a superior quality.
- The needle breakages in the knitting process will be very less.
Disadvantages Of Splicing
- To set up these process the initial cost is very high.
- The yarn strength is being reduced by 10%.
Knotting is said to be an old technique which is being not used too much because of its disadvantages.
To overcome the advantages of the knotting is being introduced. Only the initial cost to set up this is high but is easy to be worked and the production won’t be disturbed.
It won’t reduce the quality of the fabrics but will increase the quality and hence the cost of the fabric will be high.
Both the knot and splicing is being done in any one of its process depending upon the type of yarn.