Reasons, countermeasures and effects of BOPP film slitting quality ---
ten. Color circle
The factors that cause the film to roll the color circle are:
(1) Contamination equipment is contaminated: due to the pollution of the dust in the cutting workshop, as well as the operation of the equipment in the slitting process and the friction between the membrane and the friction generated by the static electricity, the cutting equipment continuously accumulates more and more dust. When it accumulates to a certain extent and fails to clean in time, it will pollute the slit film roll to form a color circle. In addition, the aging and hardening of the roll skin (sand) debris will also cause the color circle of the film roll to appear.
(2) The environment of the cutting environment is polluted: during the cutting process, due to the influence of some accidental pollution sources, such as the dust on the ceiling of the cutting machine, the exhaust of the diesel forklift, etc., the air is spread to pollute the cutting products. And form a color circle.
In order to effectively reduce the impact of color circles on product quality, the following measures must be taken:
(1) Do 5S work regularly to maintain the sanitation of the workshop and the cleanliness of the machine; (2) It is forbidden to open the doors and windows without sand filter for a long time, and keep the good habit of closing the door;
(3) The contaminated film on the surface of the parent roll must be removed before the film can be cut, so as to avoid the dirt of the surface film from contaminating the cutting machine;
(4) The diesel forklift that requires black smoke is kept away from the surrounding of the workshop to prevent the tail gas pollution from being cut into the products.
Domestic cutting machine development status and outlets ---
First, the status quo of domestic slitting machine
At present, the domestic use of the slitting machine is mainly divided into several stages, and the first stage is mainly used for the main line slitting as one slitting. One slitting is mainly provided to downstream deep processing enterprises, and the downstream customers are divided into secondary slitting or three slitting. The film making manufacturers of this meeting are mainly cut into one slitting, with the competition of film forming enterprises in recent years. Intense, in order to provide better services to downstream customers, film companies have also added a second cut. In one slitting, the most used brand is CommScope, followed by Atlas, and the Japanese slitter is rarely used in one slitting. With the rise of domestic equipment manufacturing industry in recent years, domestic slitting machines have a certain foothold in a slitting process. Of course, compared with foreign slitting machines, there is still a certain gap in domestic slitting machines. From the user's point of view, I personally think that there is a certain misunderstanding, mainly because of the lack of deep understanding of the slitter market. Everyone knows that there must be a performance price ratio when purchasing a piece of equipment. In fact, the performance and price ratio of the above mentioned brands are not necessarily the best. Some people in the United States have done such an experiment. The above-mentioned brand slitting machine is compared with the Japanese Knife cutting machine. When the same film material is cut, the result is that Japan's Kataoka wins, mainly in terms of stability and speed, speed reduction and non-stretching. Japan's Kataoka has shown superior quality and its price is lower than the above brands. Unfortunately, in the domestic film-making enterprises, no one slitting machine used Japan's Kataoka slitting machine. It is a pity that domestic companies have bought foreign second-rate equipment at the highest price. I have researched the US market. Japan's Kataoka has a high market share in the US market. I believe that with the increase in market demand and fierce competition, domestic companies will come out of this misunderstanding and re-recognize the market of slitting machines. Compared with the first slitting, the third slitting and the one slitting, the status quo of the domestic slitting machine is diversified. One slitting is mainly the importing equipment to play the leading role, while the secondary slitting and three slitting fields are in the field. The domestic market has its own magical powers, including Europe, Japan, and Taiwan. In recent years, the domestically produced slitting machines have gradually replaced the trend of foreign brands, resulting in the following results:
1. Foreign advanced cutting technology has gradually flowed to China;
2. The rise of domestic manufacturing;
3. Popularization of advanced control technology;
4, the low cost of manufacturing causes the price of the slitting machine to be low;
The above various reasons have jointly promoted the domestic film-making enterprises to choose domestic slitting machines. As time goes by, I believe that the domestic cutting opportunities become more mature and the performance is better.
Slitting machine parts ---
2. Attenuation and tension compensation of the tension of the rewinding and unwinding: It is generally believed that maintaining the constant tension of the aluminum foil during the rewinding and unwinding of the aluminum foil is beneficial to the apparent quality of the finished aluminum foil, but it is not. The best method is to increase the tension of the aluminum foil according to a certain rule as the diameter of the coil increases, and the smaller the diameter, the lower the tension value. There are automatic tension control and manual tension control during the slitting operation. The automatic tension control system is the leading set tension attenuation value, which is maintained throughout the winding process. The manual tension control requires the operator to continuously adjust the diameter of the master roll to meet the tension required for the aluminum foil during operation. When setting the automatic tension operation, set the initial tension before setting the tension attenuation value. Taking the setting of the slitting and unwinding attenuation value as an example, the setting principle is that the aluminum foil tension attenuation value (%) is equal to the tension at the end of winding of the aluminum foil minus the initial tension and then divided by the initial tension. Multiply by 100%. When setting the automatic tension value of the unwinding, it should not be too large, otherwise the aluminum foil winding surface has a large hardness and is prone to warping. But the tension should not be too small, too small and easy to cause the rewinding body to be too loose, and the winding is not neatly running. Therefore, the quality of the rewinding and unwinding during the aluminum foil slitting operation is mainly affected by the change of the tension of the aluminum foil. It can be seen that the mastery of the retracting and unwinding control system is the key to affecting the quality.
3. The change of speed during slitting affects the change of tension: When the speed is increased or decelerated, the speed of the main motor changes. Firstly, it causes the instantaneous change of the tension of the unwinding traction to the winding section of the aluminum foil, and it is necessary to slightly vibrate the aluminum foil after a period of time to gradually stabilize the tension. The instability of this tension is manifested in the fact that the finished roll is not well-wound, and the end face has unevenness, which affects the quality of the product.
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