The stretching length of the bottle cap is relatively large, so it is necessary to choose a material with a good elongation rate. The DOS lubricated aluminium closure sheet can be divided into 8011 aluminum closure sheet for bottle caps, 3004 aluminum closure sheet for bottle caps, 3105 aluminum closure sheet for bottle caps and 5052 aluminum closure sheet for bottle caps according to the combination number. The aluminium closure sheet are all hard, with hardness between H14-H24, tensile strength between 110-320, and elongation generally not less than 4. The aluminum closure sheet for pp caps specifications generally have a thickness of 0.20~43.3mm, an allowable tolerance of ±0.1%, and a width of 449-796mm.
The production of DOS lubricated aluminium closure sheet can be made by hot rolling or continuous casting and rolling, respectively, and then rolled by cold rolling. Production practice shows that the hot-rolled billet is better than the cast-rolled billet in the use effect of the anti-theft cover. The surface of the aluminium closure sheet is smooth without traces, the shape of the plate is flat, and the uncoiling performance is good. Aluminum sheet for bottle caps is mainly used in the manufacture of twist-off anti-theft bottle caps and aluminum bottle caps. The section of the aluminum closure sheet used for the bottle cap is neat, without burrs, cracks, corrosion marks, folds, bumps and other defects. The surface of the DOS treated aluminium closure sheet is degreased and clean, and the ear-making rate is low. The aluminum sheet for bottle caps produced by the company are widely used in bottle cap packaging such as wine, beverages, medical cap materials and cosmetics.
High end aluminum closure sheet are subject to chrome treatment and DOS treatment. Chromizing treatment improves the cap material aluminum plate, and the main function of DOS treatment is to prevent oxidation and scratches. The corrosion resistance of the DOS lubricated aluminium closure sheet and the bonding force with the coating. The aluminum sheet for bottle cap material has excellent moisture-proof performance, light-shielding and high barrier ability, strong mechanical performance, high blast resistance performance, strong puncture and tear resistance performance.