Can Lid Adhesive Injection Process

Can Lid Adhesive Injection Process

The can lid undergoes a complete process of stamping, adhesive injection, and drying. The purpose of adhesive injection on can lids is to provide a sealing function, which is a crucial step in cap manufacturing. Below are the relevant details regarding adhesive injection.

The goal of adhesive injection for can sealing is to apply a target volume of adhesive to the can lid, ensuring that the adhesive film achieves appropriate and even distribution. The main quality control items for the adhesive film include:

1. Adhesive amount (volume or weight of the adhesive film);

2. Correct circumferential distribution;

3. Correct radial distribution;

4. No visible gaps or defects.

A well-structured double-roll seal must adequately compress and "control the flow" of the adhesive film to fill the gaps naturally formed between the metal surfaces during sealing. If the adhesive does not flow during the formation of the roll seal, it may result in sealing defects and/or insufficient sealing. Conversely, excessive flow of the adhesive can also lead to sealing issues, such as extrusion of inner/outer adhesive or inadequate sealing.

The effectiveness of the compression applied to the adhesive during the roll sealing process in achieving an ideal seal depends on quality control. Another important function of the adhesive is to maintain a certain level of compressive flow throughout the shelf life of the canned product. This compressive flow is vital for maintaining the integrity of the seal when the rolled edges are impacted during normal handling and distribution. However, if severe damage occurs during handling, the adhesive may not provide sufficient protection.

If the above quality control standards are not met, it may result in poor sealing of the cans or an inability to maintain the seal.