The main function of the beer bottle cap is to have a certain degree of sealing to ensure that the CO2 in the bottle does not leak and the outside oxygen does not infiltrate, so as to maintain the freshness of the beer; the second is that the gasket material is non-toxic, safe and hygienic, and will not damage the beer.
In order to ensure the convenience of printing after the beer bottle cap material is formed, the surface of the bottle cap material is required to be flat, without rolling marks, scratches and stains. Generally, the alloys of aluminum closure sheet are 8011,1060 and 3105. The thickness is 0.20-0.23 and the width is 449-796 mm. The production of aluminum bottle cap materials can be made by hot rolling or continuous casting and rolling, respectively, and then rolled by cold rolling.
Aluminum pilfer proof bottle caps are made of high quality special aluminum alloy materials, which are mainly used for wine, beverages (with or without steam) and medical and health care products. It can meet special requirements such as high-temperature cooking and sterilization.
Aluminum bottle caps are mostly processed in a production line with a high degree of automation, so the requirements for the strength, elongation and dimensional deviation of the material are very strict, otherwise there will be cracks or creases during processing.
Haomei aluminum foil for bottle cap can make quality beer bottle caps. At present, the criteria for judging the quality of beer bottle caps are as follows:
1. Sealing
Instantaneous pressure: instantaneous pressure ≥ 10kg/cm2;
Chronic air leakage: According to the standard test, the chronic air leakage rate is ≤30%.
2. Cap characteristics
The first-grade paint film loss value of bottle caps is ≤16mg.
The corrosion resistance of the bottle cap usually not only meets the copper sulfate inspection without obvious rust spots, but also must delay rust during normal use.