Reconstruction Technology of Traction Knife of BOPP Film Production Line

In the production of BOPP film, according to the type of film (such as flat film, ordinary film, shrink film), it is possible to use gap winding or contact winding. When contacting the roll, if the control is improper, it will easily cause air to enter the roll and cause wrinkles, which will affect the quality of the roll. The main reason is that the cutting knife on the tractor is fixed.
When the film is rewinded, due to the unbalanced stretching effect, it is inevitable that the curling phenomenon occurs; and due to the large number of winding layers of the large film roll (about 83 cm in diameter), the cutting knife is used when the fixed knife is used to trim the edge. During the production process, it cannot move to the right or left. Therefore, when the film enters the winding, it cannot move to the left or right. This causes the film edges on both ends of the film roll to overlap in the same position. When the film ends are higher than the middle part, the film pressure in the middle If it is not true, it can easily cause the air to be carried by people, resulting in defects such as poor winding quality.
If the film can be moved left and right at the time of winding, that is, the outermost end of each film does not overlap at the same position, the cumulative thickness at both ends of the film roll will not be thicker than the middle portion. In this way, the take-up roll presses the surface of the film roll to be flat and solid. In order to achieve this goal, the cutter device of the original traction system was transformed into an automatic cutter device that can move left and right.
Remove the handwheel on the cutter screw on both sides of the original traction system. The drive unit uses a variable speed motor with a reduction gear, the power is 0.4kw, and the output shaft speed is 14r/min. The motor shaft and cutter screw are engaged by a pair of 14/40 reduction gear sets (the number of gear teeth is selected according to the speed ratio), so that the cutter screw speed is 1.4r/min. The pitch of the screw is 5mm, then the moving distance of the cutter is 7mm per minute (this is the distance of the left and right movements set by the cutter). At the beginning of production, press the cutter to jog the work switch. At this time, the cutter will work according to the pre-programmed procedure: both ends of the cutter move 7mm in the same direction, and then stop running for 5min (the stop time is set according to requirements), then the two The end of the knife and then move 7mm, and then stop running for 5min, repeat, so that when the film into the winder is also about 7mm when the winding, thus overcoming the curling edge, wrinkle and other phenomena, improve the income Volume quality.
Zhongda Company has been operating for more than three years since its transformation and has achieved good results. The quality of the film has been greatly improved, and the product's first-rate product rate has increased from 96% to 99%.