Tupperware (plastic containers with airtight lids) was invented by Earl Silas Tupper (1908-1983). Tupper was a New Hampshire tree surgeon and plastics innovator, who began experimenting with polyethylene, a new material used primarily for insulation, radar, and radio equipment. He patented the Tupperware seal in 1947.
Tupper’s first contact with plastic grew from his job at the DuPont Chemical Company which had been developing plastic before World War II. Eager to work with the new material, yet too poor to buy refined plastic, Tupper asked if he could purchase any left-over substance. His supervisor at DuPont gave him a black, inflexible piece of polyethylene slag, a waste product of the oil refining process. Tupper purified the slag and molded it to create light-weight, non-breakable containers, cups, bowls, and plates. He later designed, air-tight lids by duplicating the lid of a paint can, except in reverse.
In 1997 the Lock & Lock company designed the four locking mechanism and the sillicon seal which now made the inexpensive durable plastic containers water tight.