With the development and progress of packaging equipment, the use of automatic packaging machines is more and more common, especially in the detergent, cosmetics, food, medicine and other industries. Henkel China detergent is one of the earliest manufacturers in the industry to use automatic packaging machines. It started in the mid-1980s and has a history of more than 40 years. It has experienced the change process of domestic plastic packaging film from scratch, from a single material variety to a variety of different material structures.
Qingdao Advanmatch packaging laminated film rolls, roll film, rollstock(https://www.advanmatchpac.com/plastic-film-roll-product/) in the process of producing and operating plastic packaging film for more than 20 years, we always adhere to the principle of quality first, and have won good reputation from customers. Therefore, I hereby summarize the appearance quality problems, consequences, suggestions for improvement and acceptance standards of some films purchased by customers from other suppliers. I hope to provide some reference information for end users.
During the slitting of the film roll, due to the imbalance of the feeding and unloading forces, once the control is not good, the quality defect of uneven winding tension of the film roll will appear. It usually shows that the inner layer of the film roll is too tight and the outer layer is loose. The use of such a film roll will cause unstable operation of the packaging machine, such as uneven bag making size, film pulling deviation, and excessive edge sealing deviation, resulting in the packaging products not meeting the quality requirements. Therefore, most of such defective film roll products are returned.
To avoid this quality problem, it is necessary to take appropriate control measures to maintain the balance of winding force. At present, most film slitting machines have tension control devices, which can ensure the quality of film slitting. However, sometimes due to operation reasons, equipment reasons, large differences in the size and weight of the incoming and unloading coils and other factors, such quality defects occur from time to time. Therefore, careful operation and timely adjustment of equipment are required to ensure the quality of film roll scoring and cutting.
Uneven end face
Generally, the end face of the film roll is required to be smooth and free from unevenness. If the unevenness exceeds 2mm, it will be judged as unqualified. The uneven end face is mainly caused by many factors such as unstable operation of the coiling and cutting equipment, uneven film thickness, and unbalanced coiling force in and out. Film rolls with such quality defects will also cause unstable operation of the packaging machine, film pulling deviation, excessive edge sealing deviation and other phenomena, which cannot meet the quality requirements of qualified packaging products. Therefore, such quality defective products are usually rejected.
The so-called wavy surface is the uneven, curved and wavy surface of the membrane roll. This quality defect will not only cause the above-mentioned problems in the use of the film roll, but also directly affect the performance of the packaging materials and the appearance quality of the packaging products, such as the low tensile performance and sealing strength of the materials, and the deformation of the printed patterns and formed bags. If the quality defect is very obvious and serious, such a coil cannot be used in an automatic packaging machine.
Excessive slitting deviation
Generally, the slitting deviation of the film roll is required to be within 2-3 mm. Too much will affect the overall effect of the molding bag, such as the offset, incompleteness, asymmetry of the molding bag and other packaging product quality defects.
Joint quality generally refers to the requirements for the number, quality and marking of joints.The number of common film roll joints is required to be less than 1 for 90% of the rolls, and more than 2 for 10% of the rolls; The number of joints with film roll diameter greater than 900mm is required to be less than 3 for 90% of the rolls, and 4 to 5 for 10% of the rolls.
The film roll joint shall not be overlapped. The junction shall be located in the middle of the two patterns. The bonding shall be complete, smooth and firm. The adhesive tape shall not be too thick. Otherwise, the film will be jammed and broken, resulting in shutdown, affecting the normal operation of the packaging machine, increasing the operating burden and reducing the production efficiency. The joints shall be clearly marked to facilitate inspection, operation and treatment.
Core quality problem
Commonly used roll cores are mostly paper materials with an inner diameter of 76mm. The main quality defect is the deformation of the roll core, which causes the film roll to be unable to be normally installed on the film roll clamp of the packaging machine, so it cannot be used in production.
The main reasons for the deformation of the roll core of the film roll are the damage of the storage and transportation links, the crushing of the roll core by the excessive tension of the film roll, the poor quality and low strength of the roll core.
The method to deal with this quality defect is usually to return it to the supplier for rewinding and core replacement.
Most automatic packaging machines have certain requirements for the direction of film winding out. This requirement is mainly determined according to the structure of the packaging machine and the decoration pattern design of the packaging products. Usually bottom or top first out. Generally, this requirement is specified in the specifications or quality standards of packaging materials of each product. Such quality defects are rare under normal circumstances.
Bag making quantity
Generally, the length of the film roll is the unit of measurement. The length is mainly determined by the maximum outer diameter and load capacity of the film roll applicable to the packaging machine, and is usually used in Meters / roll.
The quality defect of insufficient number of film roll bags is also uncommon, but both the supplier and the buyer are concerned about it. Most manufacturers have assessment on the consumption index of the film coil. In addition, there is no good method for accurate measurement and inspection of the film coil during delivery and acceptance. Therefore, there are often some different opinions or disputes on this quality defect, which are usually resolved through negotiation.
Product damage mostly occurs during the process from the completion of product slitting to product delivery. There are mainly film roll damage (such as scratch, tear, hole…), film roll pollution, outer package damage (damage, water, pollution…), etc.
To avoid such quality defects, it is necessary to strengthen the management of relevant links, adopt standardized operation and effective preventive measures.
The film roll shall have clear and complete product marks, and the main contents shall include: product name, specification, packaging quantity, order number, production date, quality and supplier information.
The main purpose of this information is to meet the needs of delivery inspection and acceptance, storage and delivery, production and use, quality tracking, etc. Avoid wrong delivery and use.
The appearance quality defects of the film roll mainly occur in the subsequent process of the film roll production and the storage and transportation process. Therefore, the quality control of this link can greatly improve the product input-output qualification rate, and achieve twice the result with half the effort to improve the product quality and improve the economic benefits of the enterprise.
Post time: Oct-08-2022