Tension refers to the tension caused by the action of the air ring when the yarn is loosened. The structure of the double twisting unit of the double twisting machine mainly includes the spindle braking device, the spindle part of the double twisting machine, the yarn winding device, and the special device of the double twisting unit. Grinder A spinning machine that turns fiber strands into rovings.
The main function is to draft and twist, and to wind the roving into a certain package to meet the processing requirements of the spinning frame. During the spinning process of the spinning frame, the semi-finished roving or sliver is drafted, twisted, and wound into a spinning machine. The combed sliver and the needle-carding machine combine the sliver, the needle row is drafted to improve the sliver structure, and the roving is further spun into spun yarn on the ring spinning frame, which is the main spinning machine. During winding, the yarn is unwound from the bobbin at high speed, so that one side of the yarn between the guide hook and the bobbin rises along the axis of the bobbin, and the other side rotates along the axis of the bobbin.
Under the action of centrifugal force, a particularly conspicuous rotating object is formed, which is called a balloon. The balloon creates tension in the yarn, which varies with the shape of the airbed. You can see from HDD 2-9.
2. The production line has tension due to the tension device attached to the quilt. 3. Tension due to the friction of the thread against the yarn using the quilt. Thereby the main factor of the tension of the tension device which determines the yarn tension is installed.
When the yarn is unwinding, the tension has a certain change and development law. The yarn on the bobbin is unwound layer by layer along two tapered layers, the top of the layer has a small radius, and the bottom of the layer has a large radius. Under the condition that the winding speed remains constant, the yarn is unwound to the first At the top of the three-level structure, the angular velocity of the balloon rotation is large, and the unwinding tension is also large. When unwinding to the level and the bottom, the tension is smaller. The absolute value of the continuous change of the tension in the unwinding of the yarn in an enterprise level can be very small, without any obvious effect without any problems. However, the unwinding of the whole bobbin During the winding process, the change of the yarn surface tension has obvious advantages. When the tube is full, the unwinding tension has little effect. The number of stitches generally decreases, causing a sudden change (increase) in tension between different yarns.
When the yarn is unwound to the bottom of the cop, the friction yarn section of the yarn to the bobbin is further lengthened, so that the unwinding tension is also increased exponentially, so that when the yarn is unwound upward from the bottom of the layer model, the layer The upper yarn loop will be positioned and fallen off along the entire axial direction of the yarn bobbin, and will be blocked in the yarn inspection port of the working tensioner or the yarn finer, causing the researched yarn to reduce end breakage. Figure 2-10 shows the change in tension of the entire bobbin during winding.