The opening poem opens with a clear meaning to explain that ensuring the safety and efficiency of double-sealing is a goal that pleases both the can customer and the can factory. On the one hand, this requires continuous summarization of work experience in order to extract a simple and practical evaluation method. On the other hand, it is also necessary to adjust the double-sealing standard of “original import” that has not changed over the years. A large number of relevant practices have proved that the reasonable adjustment of the standard can be said to be beneficial but not harmful to ensure the safety and efficiency of double sealing.

The following will focus on the efficient and practical methods of double-sealing evaluation, as well as the relevant thinking and practical results in the revision of double-sealing standards.

A Practical Approach to Double Seal Evaluation

The importance of double wrapping does not need to be repeated. In order to improve the production efficiency of the can filling production line on the premise of ensuring the safety of double sealing, we have summarized some simple and practical evaluation methods.

Pay attention to the pattern of one roll (for example, about a week), take samples to check the pattern of one roll, and ensure that the pattern of one roll meets the “fifteen-character formula” as much as possible, that is, “contact without contact, the end of the can hook, and the end of the cover hook”, in order to finally obtain qualified A good basis for stable sealing results. An Angelus R77 grooved or equivalent grooved roller is recommended for the first wrapping roller.

Pay attention to the tightness. Since the thickness of the roll seal can largely reflect the relevant information of the tightness, it is recommended to carry and use a hand-held micrometer for the roll seal. Get important information about tightness in a timely manner. The recommended thickness of the wrapping is around the lower limit. For example, the current range of the wrapping thickness of the 202 can is recommended to be 1.08-1.13 mm. If the thickness of the roll seal is close to the upper limit or even exceeds the upper limit, there is a very high chance of tightness problems, and timely sampling inspection is required for confirmation. In terms of technical concept, it should be carefully understood that the thickness of the roll seal serves the key index of tightness. The real important item is the tightness rather than the thickness of the roll seal, so as to avoid being too entangled in the thickness of the roll seal.

Focus on overlapping lengths Check the two-roll graph at a reasonable frequency. When checking the two-roll pattern, first check whether the overlapping length is sufficient (try to be more than 1 mm), and then observe whether the end of the can hook and the end of the cover hook (mainly the end of the can hook) are bent and deformed.

In the case of ensuring that there are no obvious problems in the above three aspects, the indicators such as the length of the can hook, the length of the cover hook, the length of the seal, the countersink, and the thickness of the seal are allowed to fluctuate within an appropriate range, and even exceed the currently used seal. standard requirements.

In addition, if you are worried that the limited number of can sawing points (sampling points) cannot effectively reflect the real situation, you can use the method of can lid separation to observe the situation of the entire lid hook and can hook.

The above evaluation method can ensure the safety of the double sealing results, and at the same time can effectively avoid a major impact on the production efficiency, which can be described as safe, efficient and practical.

The Necessity and Feasibility of Standard Adjustment of Double Sealing

In the management system of industrial production, various standards play a very important role. They are like bright beacons on the route, guiding people’s production activities and regulating the quality and performance of products. Properly following the requirements of each standard is a rule and practical book that practitioners must study and master carefully.

Since the 1980s, my country has successively introduced foreign advanced high-speed automatic industrial production and filling application technology of aluminum two-piece cans, and at the same time, it has also introduced the double sealing standard. The standard consists of a series of indicators, the specific requirements of these indicators are mainly derived from empirical data and empirical information. Through the effective implementation of the relevant indicators in the standard, the goal of sealing safety of the sealing position is achieved, so that the sealing position can become a lasting and solid barrier effectively blocking the two worlds inside and outside the tank, and avoid the quality problem of sealing leakage.

However, many practical cases of customers show that the double sealing standard is often overinterpreted, which leads to some negative impact on the efficient operation of the production line caused by the requirements of the relevant indicators in the previous sealing standards. Insufficient understanding of the double-sealing standard, accustomed to simply using the “Go No Go” method to evaluate the sealing results, which often leads to human interference in the production process that can run normally, and the working system of the sealing machine is also affected by “Unnecessary adjustment” caused the production of the filling production line to be suspended, and even in a few cases, the filling production of the customer’s can line was seriously stopped. Over the years, in the process of technical service for some customers, we have learned that there are “unnecessary machine adjustments” in the actual production process of the can line sealing machine. The reason is related to the double sealing standard used. The understanding and implementation of relevant requirements are not unrelated, and this situation is relatively common in the industry.

As practitioners, can we make some appropriate adjustments and revisions to the standards within our ability to improve this situation? The seriousness of standards should be protected, but at the same time standardization is also a process of continuous improvement. Through the implementation process, problems existing in the formulation of standards are found and continuous improvement, so as to continuously improve product quality, management level, economic benefits, and enable enterprises to develop continuously. Therefore, the standard will not remain static, but should be updated and developed from time to time on a case-by-case basis. In addition, from the point of view of the classification of standards, the double-envelope standard should be classified into the category of guiding technical documents in industry standards or enterprise standards, rather than the more serious mandatory standards with legal attributes. Consideration of these attributes of the resealing standard gives us more confidence in the idea of ​​revising the wrapping standard.

Before the revision, we practiced first, and completed a large number of experiments with the active cooperation of the young guards of some customer manufacturers. The results show that the appropriate adjustment of the relevant indicators in the double sealing standard can fully ensure the safety of the sealing without any leakage or other negative effects that people worry about. Therefore, it is possible to further optimize the sealing. The double-sealing standard recommended to customers.

The principle of revision of the content of the double-envelope standard

With the strong support of a large number of practical results, we made appropriate adjustments to the double-sealing standard at that time from many aspects, including a more reasonable expansion of the relevant parameter range, and added more detailed and necessary descriptions. We try to help the customer’s double-sealing evaluators to understand the meaning of the sealing standard more thoroughly through the revision to a certain extent, so as to facilitate their use, and also help the customer’s can line to improve the production flow on the premise of ensuring the safety of the sealing. performance and productivity.

The reason for optimizing the customer’s double-sealing recommendation standard is also considering that the graphic observation method of double-sealing has basically become the mainstream detection method. Therefore, for the content and expression form of the double envelope standard, we take the two perspectives of necessity and the convenience of on-site personnel as the starting point. The standard for double wrapping has been revised in four aspects, including “Description”.

Simplify the content First of all, remove the content that has little practical significance and “appears to be redundant”, and strive to make it more concise, better to use, and more friendly. Compared with the earlier version, it not only does not include items such as seam clearance, can hook overlap rate and other items that have no great practical significance in the relevant standards in the past, but also cancels the set value and only retains the operating value (that is, the operating specification).

Concise expression Secondly, the expression of positive and negative deviations of basic dimensions in the operating specifications is intentionally changed to the interval expression of the minimum and maximum values. The latter may seem unprofessional, but it is concise and intuitive, which can help the on-site operators of the factory. It is more beneficial to judge at a glance whether the test results are within the required range, from the point of view of simple, efficient and practical information transmission.

Scope expansion In addition, the allowable scope of non-critical dimensions has been appropriately relaxed, and necessary text descriptions have been added.

Add description Finally, the relevant requirements for the first roll are clearly put forward. At the same time, in order to help customers adjust the sealing machine more conveniently, we continue to make clear recommendations to customers on the more important first roller grooves, pin gauges, spring pressure, etc. in the standard.


Since the double-sealing standard is basically accumulated from some relevant experience data and information, this revision of ours may be said to be a bold move to not stick to the rules and keep pace with the times on the premise of respecting the past experience of the forerunners Practice is also a kind of pursuit of development with the mentality of “inheriting, developing, integrating and sublimating”, moving from pure empiricism to the targeted change of realistic pragmatism required in the field of beverage packaging, and embodies “complex things are simple. do” concept.

Finally, it needs to be emphasized that this revision of the double-sealing standard for cans (lid) of the same type and specification in different can factories is an adjustment without any compromise on the safety of the roll seal. The requirements for important indicators of sealing safety have not only not been relaxed, but have become more stringent.

Over the past few years, some major customers have successively adopted the revised double wrapping standard, and a large number of practical results have strongly verified the safety of the revised standard.