文档介绍：Lesson 5
Metal Containers
第5课金属容器
Background
Steel is one of the older packaging materials.
- Originally used for round, square, and rectangular boxes and canisters.
- The old-fashioned appearance of a fabricated metal box is effectively used to create nostalgia for specialty and gift-type containers.
- Sanitary food can, hand-soldered cylindrical metal cans started in the early l800s.
- Metal cans’ advantages:
Background
being relatively inexpensive
capable of being thermally processed
rigid
easy to process on high-speed lines
readily recyclable
total barrier to gas and light
an important means of delivering a shelf-stable product
- Food cans: three-piece construction (Figure ).
Background
Figure Three-piece (left) and two-piece(right) can construction
Background
Shallow drawn containers with friction or slip covers
- Two-piece shallow drawn cans with double-seamed
(folded) ends
- Two-piece cans (Figure ).
reduced metal usage
improved appearance
elimination of a possible leakage location
more elaborate tooling required
- Deeper draws and multiple draws and draw-and-iron
process
-Impact-extrusion: tin, lead, and Al; collapsible tubes
(nearly Al); heavier gauge aluminum extrusions used for
pressurized aerosol containers
Common Metal Container Shapes
Three-piece steel sanitary food cans.
·Aerosol cans, made by two methods: (1) Three-piece steel cans with a welded body and two ends, and (2) one-piece, impact-extruded aluminum cans necked-in to accept the valve cup.
·Steel or aluminum two-piece drawn-and-ironed beverage cans.
·Two-piece steel or aluminum cans by drawing or by draw and redraw.
Full-opening, ring pull-top cans
Double-seamed, conventional-top cans
·Cans with hinged lids, usually steel
Common Metal Container Shapes
Flat round cans of drawn steel or aluminum with slipcovers (Figure )
·Three-piece steel or aluminum ovals, typically fitted with a dispensing spout (Figure )
·Traditional pear-shaped, three-