Polyethylene terephthalate bottle has base made up of triangular sections fitting together to form cone which be cut out using tool with radial cutters, allowing bottles to be stacked inside each other

摘要

Polyethylene terephthalate bottle has a base made up of triangular sections which fit together to form an inwardly-projecting cone. This can be cut out using a tool with radial cutters, allowing the bottles to be stacked inside each other.