The Pure-Pak carton has come a long way since its humble start in 1915. Since then, it has undergone continuous development in order to satisfy consumers and to protect its contents.

Food packaging has been crucial since the birth of the industrial era when consumers moved into cities, away from the food production areas. But food preservation and storage has existed since ancient times.

Natural materials like woven wicker baskets, animal skins and clay have been used to store, distribute and protect food since the beginning of civilisation.

Glass-making existed 6,000 years ago, but it was not until 200 BC that an unknown Syrian discovered that he could blow molten glass with a pipe, and by turning it, he could make a bottle.

Milk in particular has always been difficult to preserve, due to its susceptibility to disease-causing agents. This was one of the reasons for high infant mortality rates.

Milk was also easily spoiled and quickly absorbed odours. The heavy returnable glass bottles of early days necessitated local dairy operations and an energy-intensive distribution and filling process.

The first paper-based milk containers were sold on the streets of San Francisco and Los Angeles as early as 1906. But the solution was not very practical and disappeared completely from the market shortly thereafter.

The problem was not only to find a suitable material to coat the normally penetrable paper, but to find a bonding material for the bottom that was acceptable for food applications. Paraffin and microcrystalline waxes were used to coat the paper and animal glues were used to bond the bottom of the carton with varying degrees of success.

The US Patent Office granted John Van Wormer a patent for his "paper bottle" on October 19, 1915. His patent was later acquired by the American Paper Bottle Company.

Several years were spent perfecting the Pure-Pak container and the machinery which formed, filled and sealed it. The first six machines were built between 1929 and 1934.

The Ex-Cell-O Corporation in Detroit was approached by the American Paper Bottle Company in 1934. The Detroit-based company, which specialised in supplying machinery to the growing automobile and airplane industries, started by building machines for the American Paper Bottle Company and eventually acquired the rights to manufacture and distribute the Pure-Pak system.

Upon taking over the first thing Ex-Cell-O set out to do was to make a tab on the side of the gable which would make pouring possible. This opening device was primitive by today's standards and it was not until the mid-1950s that today's spout was introduced.

Because the cartons were single-service and didn't need to be returned, dairies were able to extend their operations beyond locally-imposed markets.

Several competing systems were launched around 1930 but none survived. Pure-Pak's unique selling point was the fact that the packages were delivered flat, saving storage and transport costs.

From sales of 42 million units in 1937 (the first full year on the market) to today's sales of some 30,000 million units, the system has come a long way.

The traditional milk carton now houses other liquid products such as wine, water, edible oils, soups, fruit preserves and even industrial products such as detergents and fabric softeners.

Energy-efficient production, reduction of carton weight and improved sealing and opening techniques have kept the paper carton on the cutting edge of packaging technology.