Cap packaging

Descriptions for cap packaging products

Owing to the huge development of aluminum cans, it becomes one of the most important necessities in our daily life especially the beverage packaging in food packaging market. The reasons are as below:

  • Reliability aspect：
    Light weights (Specific gravity of aluminum is 2.7g/cm3 ); Easy for storage; Good sealability; Not easily breakable to avoid accidents or damages.
  • Characteristic aspect:
    Aluminum can be easily processed to the maximum volume. Besides, foods can be preserved longer on account of its lightproofness characteristic.
  • Environmental aspect:
    Better printability; Landscaping design for environmental purposes; High residual values; Available for vending machines; Recyclable.

Product applications

The size of can end can be specified as the figure as right:

  • 200
    lid
    2 inches
  • 202
    lid
    2 2/16 inches
  • 206
    lid
    2 6/16 inches
    Two-piece cans and Three-piece cans
  • 209
    lid
    2 9/16 inches
    Three-piece cans

The lids can be divided into different categories baed on the opening methods:

  • SOT Stay on Tab Stay on Tab Lid. The ring will stay on the lid when opened it. Widely used. (Beer, coke, etc.)
  • RPT Ring Pull Tab Ring Pull Off Lid. The ring will be lifted completely when opened it. (The lid can be used for printability or promotion.)
  • FA Full Aperture The lid will be pulled off completely when lifted the ring. e.g. Fish can packaging. (Cans for Eight sweet ingredient porridge, pickle, etc.)

Future trends

The production cost of aluminum cans has been reduced for increasing price competitiveness. Furthermore, the materials have also been improved for becoming thinner and stronger. Take #206 cans as an example, it used to be 25g and above during the 50s but its thickness has been improved to 0.27mm over decades of continuous efforts. Besides, the bore diameter has been narrowed; compared to the same capacity of 330ml, the weight of #202 cans has been reduced to nearly 13g. In addition to the shorter bore diameter, the thickness of can lid has been deducted from 0.27 mm to 0.22mm which means the material saving is up to 25%. Even though the thickness has been changed, the basic requirements will stay the same, such as internal pressurization test, formability, and eating ratio. Moreover, the higher mechanical properties are highly required due to the reduction of strength.

Cap Feature Comparison

  Three-piece Can (209) Two-piece Can (206) Two-piece Can (202)
Yield Stress(N/mm2) Avg.250 Avg.330 Avg.350
Internal Pressure (KPa) No specific requirement above 630 above 650
Weight(g) 4.2 3.3 2.7