Depth analysis of causes of rust in beer bottle caps and countermeasures

In the peak season of beer consumption, “rust spots in finished beer caps” have become the focus of consumer complaints. This not only affects the brand image, but also has security risks. In this article, the author discusses the reasons for the rust of beer bottle caps as follows.

1. The effect of baking temperature or time.

If the baking time is too long, the varnish and coating applied on the iron plate will become brittle; if not, the varnish and coating applied on the iron plate will not be completely cured.

2. The amount of coating is insufficient.

When the cap is stamped from the printed iron plate, untreated iron is exposed at the edge of the cap. The exposed parts are prone to rust in high-humidity environments.

3. The vertical and horizontal asymmetry of the gland star causes rust spots to occur.

4. During handling of the logistics, collisions between the caps cause rust spots to occur.

5. The internal wear of the capping die and the low height of the capping punch will aggravate the abrasion of the capping die on the cap.

6. After the bottle cap with water is pasted with aluminum foil, or immediately packed (plastic bag), the moisture is not easy to evaporate, so that the corrosion process is accelerated.

7. Blast the bottle during pasteurization to reduce the pH of the water and easily accelerate the rust of the bottle cap.

Based on the above reasons, we should focus on the following aspects:

1. Strengthen the appearance and corrosion resistance of beer bottle caps before entering the factory.

2. During the inspection process, especially when changing the supplier, the inspection of the corrosion of the cap after sterilization of the beer should be strictly strengthened.

3. Strictly carry out the indentation inspection of the bottle caps, and the packing shop should check the capping quality at any time.

4. Strengthen inspection of the filling star and filling die of the filling machine and crush the bottle and clean it in time.

5. The manufacturer can purify the residual moisture of the cap before the code is sprayed, which can ensure the quality of the code (spray in the bottle cap), and can also play a positive role in the rust prevention of the beer cap.

In addition, an article pointed out that the use of chrome-plated iron than galvanized iron has a stronger rust resistance.