# How Earl Tupper Invented the Airtight Plastic Food Container

> A 1947 patent for a flexible plastic container with a unique, airtight lid that seals by pressing down on the center, creating the foundation for Tupperware.

- **Patent:** US 2487400
- **Original title:** Open mouth container and nonsnap type of closure therefor
- **Owner:** Individual
- **Granted:** 1949
- **Status:** Public domain (expired)
- **Times cited:** 116
- **Field:** consumer_electronics, mechanical, materials

## What it does

The patent describes a container made of flexible plastic with a groove around the rim. The lid is designed with a matching ridge. When the user presses the center of the lid, it forces the air out and creates a vacuum-like seal against the container wall. This mechanism allows for a secure closure without needing complex mechanical latches or snaps.

## What it does NOT cover

- Does not cover rigid glass or metal containers that cannot flex to form a seal.
- Does not cover lids that require mechanical hinges or external clamps to stay closed.
- Does not cover containers made of non-polyethylene materials that lack the necessary flexibility.

## The clever bit

The genius was using the material's own flexibility to create a seal, rather than relying on a separate gasket or mechanical locking mechanism.

## Real-world examples

1. Original Tupperware containers
2. Modern flexible plastic food storage bowls
3. Generic airtight plastic kitchen canisters

## Why it matters

This invention launched the food storage industry as we know it. By enabling an airtight seal in a lightweight, durable plastic, it changed how families stored leftovers and led to the iconic Tupperware party business model.

## Frequently asked questions

### What does How Earl Tupper Invented the Airtight Plastic Food Container cover?

A 1947 patent for a flexible plastic container with a unique, airtight lid that seals by pressing down on the center, creating the foundation for Tupperware.

### Who owns patent US 2487400?

Individual owns this patent, granted in 1949.

### When does this patent expire?

This patent has expired and is now in the public domain — anyone can use the invention freely.

### What is patent US 2487400 cited by?

This patent has been cited by 116 later patents that build on its ideas.

### What problem does this patent solve?

This invention launched the food storage industry as we know it. By enabling an airtight seal in a lightweight, durable plastic, it changed how families stored leftovers and led to the iconic Tupperware party business model.

### What does this patent NOT cover?

Does not cover rigid glass or metal containers that cannot flex to form a seal.

**Full plain-English explainer:** https://patentbrief.org/patent/us/2487400/tupperware-airtight-seal

**Original patent:** https://patents.google.com/patent/US2487400

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_Source: PatentBrief — https://patentbrief.org. Patent facts are from public records; the plain-English explanation is PatentBrief's._


## Related patents

Semantically similar inventions in the PatentBrief corpus:

- [John Mason's 1858 Patent for the Mason Jar Lid](https://patentbrief.org/patent/us/22186/mason-jar) — An 1858 invention by John L. Mason that introduced a threaded glass jar and a screw-on metal lid to create an airtight seal for home food preservation.
- [The Invention of the Modern Soda Can Pull-Tab](https://patentbrief.org/patent/us/3349949/pull-tab-pop-top-can) — A 1965 design for a ring-shaped metal tab that makes it easy to pull open a tear strip on a beverage can.
- [How Pringles Potato Chips Are Stacked and Packaged](https://patentbrief.org/patent/us/3498798/pringles-stackable-chips) — A 1970 patent by Procter and Gamble describing the precise method for stacking uniform, saddle-shaped potato chips into a cylindrical container to prevent breakage.
- [How the Crown Cork Bottle Cap Changed Soda and Beer](https://patentbrief.org/patent/us/468226/bottle-cap-crown-cork-painter) — William Painter's 1892 invention of the crown cork bottle cap, a simple metal disc with a crimped edge that provided an airtight, disposable seal for carbonated beverages.
- [How a Spring-Loaded Pocket Dispenser Works](https://patentbrief.org/patent/us/2620061/pez-dispenser) — A 1949 mechanical design for a pocket-sized container that uses a spring to push items like pills or candies to the top for easy access.