Garbage bin(truck) can be made by injection molding and rotomolding.In China,most garbage bin is injection.In foreign countries,has many rotational types.
The most common rotational molds is sheet metal molds.We usually call steel mold.It is mainly used for large and simple structure parts.eg. Water tanks.
In the earlier times,steel mold just need to be simply hammered and welded by hand.But now,the production with more mechanical process.eg. CNC,laser cutting,mechanical stretching,mechanical bending,etc.And the parts can be more complicate.For some ribs and radian parts we did compression mold first to make molds more sooth and beautiful appearance.
