Roll up cigarette packs consume a lot of material and are prone to curling. Use this trick to break through perfectly!
With the promotion and widespread application of ultra high speed cigarette packaging machines in the cigarette packaging industry, the demand for equipment in the cigarette packaging industry is becoming increasingly high. The current trend of coil packaging methods is increasing, but in actual production, there are problems such as excessive consumption of coil tobacco materials and a large amount of remaining materials on discarded coil cores. This not only leads to an increase in production costs, but also goes against the goals of various cigarette packaging printing companies to improve quality and reduce consumption. At present, how to quickly adapt coil cigarette packaging materials to production needs, improve machine adaptability in a short period of time, and reduce consumption has become an important issue facing us.
Advantages and disadvantages of coil materials
01/Advantages
(1) Good continuity allows for continuous feeding of coil materials, reducing the frequency of material replacement and improving production efficiency.
(2) High degree of automation, easy to use in conjunction with automated equipment, achieving automated production and reducing manual operation costs.
(3) Space saving, coil materials are relatively space saving during storage and transportation.
02/Disadvantages
(1) The adaptability issue of materials on the machine. Some materials may experience curling, bending, and other issues that affect normal use, leading to high frequency of equipment failures and even affecting product quality, resulting in material waste.
(2) Problem with automatic splicing detection system. The material requires high precision for the detection system, which may lead to inaccurate splicing timing during high-speed production, resulting in excessive material waste and increased costs.
In response to the relevant influencing factors, we have established a research group to optimize and apply coil type cigarette packaging materials, in order to achieve the goal of improving the adaptability of box packaging paper rolls and reducing energy consumption.
Main research content of the project
01/Multiple splicing of multi joint products leads to excessive consumption
There are too many rewinding joints in the production process, which is actually caused by the process control of each link.
(1) Ink improvement
Improve the quality of the main color ink used in the product and reduce unnecessary downtime caused by product defects. Improve the fineness of gold ink and reduce the occurrence of defects such as gold trailing and stretching during the printing process; When adding red ink, filter it with a 400 mesh filter, strictly control the ink viscosity, reduce printing line defects during the production process, and reduce the number of rewinding joints.
(2) Improvement of hot stamping process
Improvement of hot stamping plate: Copper alloy is replaced with alloy steel engraving plate to ensure the precision of hot stamping and improve the problem of missing and broken marks caused by the collapse of hot stamping plate in the production process.
Improvement of aluminum foil quality: Strictly control the number of aluminum foil joints, match the length of aluminum foil with the length of paper, and reduce the occurrence of intermediate material replacement joints.
After communicating with upstream suppliers, we optimized and improved the quality of hot stamping plates and aluminum electroplating, reducing downtime and minimizing the number of joints produced.
(3) Information based control of defect length for online detection
In the production process, defective products in each process are inevitable. In order to accurately record the interval length of these defective products and facilitate the subsequent calculation of plate length, we have introduced an online detection system on the production line, as shown in Figure 1.
Figure 1 Online detection system
Through high-precision sensors and image recognition technology, real-time scanning and detection of products on the production line are carried out. Once a defective product is discovered, the system immediately records it and analyzes its interval length through algorithms. In addition, we need to establish a comprehensive database system to store this data and provide basic data support for the subsequent calculation of platter length, as shown in Figure 2.
Figure 2: Database System
(4) Information technology control of cutting process joints
During the slitting process, not only should defective products be removed, but also the length of genuine products should be checked and recorded online. In this way, products that can be spliced together can be combined to reduce the number of joints caused by multiple splices. Use algorithms to process these data and analyze the optimal stitching scheme.
As shown in Figure 3, the length of genuine products is detected and recorded in real-time using high-precision measuring equipment. Then, use algorithms to process these data and analyze the optimal stitching scheme. Minimize the number of joints as much as possible while ensuring product quality. In addition, we also need to control the speed of the production line to ensure fast production while also ensuring the quality of the joints.
Figure 3 High precision measuring equipment
Through various improvements mentioned above, we have reduced the number of joints per roll from 2-3 to 1, which not only improves product quality but also reduces the number of cigarette machine shutdowns and waste caused by roll changing. Meanwhile, due to the reduction of joints, production costs and material consumption have also been lowered.
02/Improvement of the problem of excessive residual tobacco materials caused by material curling
The main factors affecting material curling include product moisture content and winding tension.
(1) Moisture content control
Moisture content is one of the important indicators of material adaptability on the machine. The higher the moisture content of paper, the softer the product. However, for machine cigarette packs, high moisture content, good material adaptability, and less likely to cause edge and mouth explosion, but the product is prone to warping; Low moisture content and good flatness of the product, but the product is too hard and the rebound of the paper will increase, resulting in weak adhesion, edge explosion, and surface cracking of the product. Therefore, it is necessary to control the temperature and humidity of the production environment and install an automatic humidification system, as shown in Figure 4, to achieve a relatively balanced state.
Figure 4: Automatic Humidification System
The control of coil type and flat type materials is different. Through on-site investigation, the temperature and humidity in the coil car room were found to be 59.9% humidity and 24.7 ℃ temperature.
Based on the investigation results, the changes in the product under different temperature and humidity environments were simulated in a temperature and humidity chamber, and an experimental plan was developed. The experimental results are shown in Table 1, and the comparison of curling degree before and after different temperature and humidity experiments is shown in Figure 5. The experimental results indicate that the optimal temperature and humidity for the coil soft label material obtained through the experiment are 22 ℃ and 60% humidity.
Figure 5 Comparison of Curling Degree Before and After Different Temperature and Humidity Experiments
Table 1: Product Changes under Different Temperature and Humidity Environments Simulated in a Temperature and Humidity Simulation Box
(2) Roll tension control
In addition to the issue of paper moisture content, tension control during unwinding and unwinding is another important indicator that leads to curling. From a subjective perspective, the smaller the core diameter of the coiled product, the greater the deformation of the inner ring product, and conversely, the larger the core diameter, the smaller the deformation. However, the actual situation is that the smaller the diameter of the core, the greater the tension required for winding during the printing process, and the smaller the tension required for unwinding using the winding machine. On the contrary, the larger the diameter of the core, the smaller the tension required for winding during the printing process. However, the tension required for unwinding the winding machine will increase, which poses a risk of product breakage.
In addition, when the quantity of products per disc is constant, the larger the diameter of the core of the disc, the larger the outer diameter. However, the unwinding unit of the winding machine has a limited height and cannot consider cores with excessively large diameters. In addition, considering that paper cores were initially used in the production of this product, these cores are prone to damage or deformation and cannot be reused, resulting in a certain degree of waste.
Therefore, two types of nylon core were selected for testing, with a wall thickness of 150mm inner diameter, 10mm wall thickness, and 160mm outer diameter, as well as an inner diameter of 150mm, 15mm wall thickness, and 165mm outer diameter, as shown in Figure 6. The reason for choosing nylon material is that it is not easily deformed and can be reused repeatedly, thereby achieving the goal of reducing costs.
Figure 6: Selecting two types of nylon core for testing
In addition, the process parameters for the tightness of the winding were optimized, and the cutting and winding tension was adjusted from 115-120N to 100-105N. During the testing process, there were three tension adjustment schemes: 90-95N, 95-100N, and 100-105N. Among them, three trademark paper rolls had loose cores at 90-95N, one trademark paper roll had loose cores at 95-100N, and there was no loose trend at 100-105N. Therefore, it was decided to wind at 100-105N. The trademark paper has been tested on the machine, and the flatness of the trademark paper at the core position has been improved to some extent. The product has no curled edges or loose core.
By adjusting the inner diameter of the nylon core to 150mm, the wall thickness to 10mm, and the outer diameter to 160mm, the inner diameter to 150mm, the wall thickness to 15mm, and the outer diameter to 165mm were tested and verified on the machine. After cutting the trademark paper of the core into small sheets, the curling degree was basically the same. As the wall thickness increased, the material splicing time needed to be advanced with the increase of wall thickness, and there was no significant change in the remaining material.
The conclusion drawn from this verification is that the nylon core with an inner diameter of 150mm, a wall thickness of 10mm, and an outer diameter of 160mm can meet the requirements for machine adaptability.
Conclusion
By online defect length control and slitting process joint control, the optimization of the product effectively reduces the number of joints and directly increases the usage of coiled products; Improved the environmental temperature and humidity, as well as the curl degree of the recovered roll, clarified the impact of temperature and humidity changes during dry and wet seasons on the product, homogenized the change in recovered roll, and ensured the variables caused by such factors; Confirmed the reusability of nylon material and the practicality of 10mm wall thickness core to meet production needs.
Through precise production control and advanced sensor and image recognition technology, the algorithm and control strategy of the cutting process can be optimized to achieve accurate detection of product defects and precise control of length. This not only improves product quality, but also reduces production costs and material consumption, providing strong support for the sustainable development of enterprises.
In the future, with the continuous development and progress of technology, as well as the continuous innovation and efforts of the company, we will be more effective and efficient in achieving higher utilization rates of coil products, bringing greater benefits and value to the manufacturing industry.