Tension information detection method
(1) Tension sensor detection method: It is a method of detecting the tension directly, closely combined with the machine, and without moving parts. Usually two sensors are paired and mounted on the end shafts on both sides of the detection guide roller.
(2) Roll diameter calculation type detection method: It uses the proximity switch installed at the reel to detect the rotation speed of the reel. Because the reel rotates once, the winding diameter will change twice the thickness of the material.
The current diameter of the reel is obtained by cumulative calculation by the initial value of the reel diameter and the material thickness, and the change of the corresponding reel diameter reflects the change of the actual tension value.
(3) Floating roller position detection mode: It uses the cylinder attached to the slitter to connect the floating roller to drive the angular displacement sensor to detect the tension change. When the tension is stable, the tension on the material is balanced with the cylinder force, so that the floating roller is in the center position. When the tension changes, the balance between the tension and the cylinder force is broken, and the position of the floating roller will rise or fall. At this time, the swing lever will rotate around a point and drive the floating roller angular displacement sensor to rotate together.
(4) Floating roller position + tension sensor combined tension detection mode: It can simultaneously detect the floating roller position signal output by the floating roller angular displacement sensor and the tension signal output by the tension sensor, thereby providing higher precision tension control to the system. .
Causes, countermeasures and effects on the quality of BOPP film slitting quality ---
(iv) Effect of film roll tightness on product quality
1. The winding is too tight:
1 fluttering/starting bone: As BOPP film, it is normal for the thickness of the product to fluctuate within a reasonable range. If the reeling tightness is appropriate, this thickness fluctuation will not affect the quality of use, but when the slitting is too tight The thicker layers of the film are stacked together to cause edge thickness or bone swelling, which affects the quality of use. The fluttering or bone formation that is formed by over-tightening is often difficult to find during the slitting process, but after the product has been stored for a period of time, the problem will be highlighted. In addition, there are several types of products with uneven thickness defects that can be easily revealed, such as ultra-transparent tape film, crystal film, heat sealing film, etc., while fluttering and bone-starting phenomenon will cause different quality of all film products. The degree of influence, especially for products that require printing and processing, is particularly prominent.
2 Adhesion: over-tightening of double-sided corona products, anti-corona products and products with less anti-adhesive content will cause adhesion quality problems, and the problem can only be found in the customer's use, the impact is great, and appears Products with adhesion problems can only be disposed of as scrapping, causing large losses to the company.
3 Face wrinkles: Due to the tight winding, the film cushioning performance is degraded. The wrinkles formed by the extrusion of the film on the end face of the product during handling and loading and unloading are difficult to eliminate, forming the end wrinkles and affecting the quality of the product.
4 Pitting: Due to the tightness of the winding, the film near the paper tube is affected by the rough surface of the paper tube, which causes pitting, which affects the quality of the product. The use of the polished paper tube will eliminate the surface of the film and improve it. Start wrinkles).
Reasons, countermeasures and effects of BOPP film slitting quality ---
In addition, sometimes scratches due to slitting are difficult to detect by the naked eye, but scratches (scratches) will attenuate the corona value of the product. According to experience, the corona value is reduced by about half in the normal cutting process. Dyne, when the corona values ??differ by more than one dyne before and after cutting, the reasons for the cutting process, such as the speed ratio of the driving roller, the quality of the sand skin, the condition of the sipe roll, etc., should be checked to eliminate the influence. .
It is worth mentioning that there is a kind of abrasion that is caused by the slitting process, but it is mainly caused by the cutting factor. It is mainly that the mother roll is too loose, and the product of the loose part is horizontally or vertically tilted during the slitting process. While scratching the film surface, it is found that the phenomenon is to install the upper splint on the mother roll for positioning, and secondly, the cutting speed should be properly controlled, and the influence of the quality of the mother roll on the cutting quality can be improved as much as possible.
Zhengzhou EAST IMPORT AND EXPORT co., ltd . ( a goulian group of company) a manufacturer and exporter for all kind of packaging machinery , like bopp tape coating machines, bopp tape slitting machines. Bopp tape core cutter, bopp tape core loader etc