Building motion and bobbin traverse in jute spinning:
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Empty bobbins are arranged on the carrier of the spinning frame bobbin rail. The flyer revolves around the bobbin at a certain speed. The bobbin also starts spinning by pulling the flyer’s thread. However, the speed of the bobbin is less than the speed of the flyer. Therefore, this low speed is the speed at which the yarn spins in the bobbin, which tends to be at a certain rate and the bobbins move at a certain speed along the bobbin rail. https://bdfabric.com/building-and-winding-in-jute-spinning-process/
As a result, one layer after another is arranged in the bobbin, thus gradually becoming the bobbin building. After the bobbin is full, the spinner shuts down the machine, leaves the empty bobbin in the carrier, sends the full bobbin to the winding section, and restarts the machine. Some modern machines have an auto doffing system. There, just after the bobbin is full, pressing the button, the doffing process is done automatically. https://bdfabric.com/jute-spinning-frame-and-its-objectives/
In the jute spinning frame, from the bottom to the top of the empty bobbin and from the top to the bottom in such a way that the work of gently wrapping the yarn in the bobbin is done is called Bobbin building.
Building motion in jute spinning:
The machine that allows the yarn package (bobbin) to be smooth, that is, the layer of yarn to be wrapped around the bobbin by sticking to one surface is called building motion. The bobbin rail has a lever on one side of the spinning frame, which has a falcon at one end, and a cam called a heart cam in the middle to lift the lever. The other end of the lever has an adjustable slot with a chain attached to a connecting rod through the stand.
Building motion and bobbin traverse in jute spinning. The builder is attached to the surface of the quadrant in such a way that some parts of the chain extend beyond the quadrant and the circumference. The builder shaft pulley is attached to the surface of the builder quadrant. The builder becomes a chain guide from the shaft pulley to the builder bracket. A bobbin rail is attached to the builder bracket. The bobbin carriers are housed on bobbin rails. Empty bobbins are placed in bobbin carriers.
Working process of building motion:
When the lever is closest to the heart cam, the bobbin rail is down and the heart cam rotates and the distance from the heart cam to the lever gradually increases. The bobbin rail slowly rises to the top, and as the farthest point of the heart cam falls to the bottom of the bowl, so does the bobbin rail. In this way, as the machine runs, the yarn in the bobbin starts to get entangled in layers. When the closest point from the center of the heart cam is at the bottom of the bowl, the exact opposite happens, that is, the bobbin goes down. In this way, the bobbin building gradually came to be.
Bobbin traverse in jute spinning:
The bobbin used in the jute spinning frame has two fringes on either side. And the bar in the middle is called Sank. During bobbin building, the bobbin rails along with the flyer’s eye with the rails, so that the resulting yarn gets entangled in the rotating bobbin. The method by which the yarn produced from the top fringe to the bottom fringe of the bobbin moves up and down, i.e. the bobbin moves up and down, is called bobbin traverse.