Britain's second richest man, Hans Rausing, owes it all to the ubiquitous Tetra Pak cardboard container. At the age of 74, however, rather than enjoy his retirement Rausing is embarking on a new milk packaging revolution, producing biodegradable bottles out of chalk. The last five years have seen little commercial packaging inactivity for Rausing, a period enforced by a 1995 deal in which he sold his share of the family Tetra empire to his brother Gad for an estimated £4bn (US$5.6bn). During this time a small Swedish company called