a. Field of Invention
This invention pertains to a drum made of several components and having a unique cross-sectional shape, and more particularly to a drum having generally square or rectangular cross sectional shape with rounded corners and including a self supporting plastic liner surrounded by a corrugated fiber shell.
b. Background of the Invention
Various goods, including liquids, dry or powdery materials, or semi-liquid goods are preferably shipped and stored in drums. Preferably these drums must be light weight so that they reduce the overall shipping weight and costs, and so that they can be manipulated easily when they are empty. Another criteria considered in making the drums is that they should have a shape which is space efficient so that a large number of drums can be stored efficiently in a small amount of space either during shipping or storage. Over the years drums having various shapes have been tried in the industry. For example cylindrical drums have been tried which are strong structurally but are not space-efficient because when several such drums are disposed side by side, there is a considerable amount of space left therebetween. Square or rectangular containers are much more space efficient since they can be disposed side-by side with virtually no dead space therebetween. However structurally they are not as strong as cylindrical drums, and furthermore such containers present sharp vertical edges which are particularly prone to crushing and even rupture.
Additionally, it was found that it is advantageous to make a drum made of two components: a plastic inner lining disposed in a fiber shell. However the shell must be usually made strong enough to support the inner lining and therefore it is usually bulky and must include various lining reinforcing means.