Patent Awarded for Ropak Packaging’s Container Sidewall Strengthening System

Ropak Packaging, the largest producer of rigid plastic shipping containers in North America, has been awarded U.S. Patent No. US 7,740,149 B2, on June 22, 2010, for its innovative container sidewall strengthening system – dubbed the 'corner groove product feature'.

This is an important patent for Ropak as it allows for a reduction in the amount of source material used in making the injection molded containers, while retaining their performance – in particular their stack strength. The patent covers nestable plastic containers for transporting and storing goods and materials, but offers most benefit in square and rectangular containers, where the corners carry the load.

Ropak's corner groove product feature includes vertical grooves and horizontal reinforcing ribs, which together increase the load the containers can bear without increasing their weight.  The innovative features mean the containers are able to resist buckling under downward forces that would normally make them collapse.

If stack strength retention is the goal, the corner groove feature allows the wall thickness of the container to be reduced, cutting the amount of source material used in manufacture. An added bonus of reducing the wall thickness is that the nesting height in turn is also reduced – resulting in more empty containers per pallet and a consequent reduction in the number of trucks required to transport them.

The corner groove feature adds to Ropak's impressive line-up of source-reduced containers. The lightweighting results in fewer greenhouse gas (GHG) emissions, less energy required in manufacture and transport, and minimizes waste.

Ropak's Marketing Manager, Pansy Leo, commented: "Of the various routes to increasing sustainability we thought reduction in source material was the most logical path to follow. By coupling source reduction with high levels of reusability, significantly less waste is generated. The U.S. EPA lists source reduction as the number one initiative in combating our municipal solid waste issues."