Abstract: A rigid or semi-rigid plastics sheet material comprises a pair of opposed faces (20,22) between which run elongate voids defined by interconnections (24,25) between the two opposite faces, the cross sectional shape of at least some of the voids being a polygon with more than four sides, preferably a repeating pattern of regular hexagons or octagons joined in a line at adjacent sides or apices and including triangular secondary voids therebetween. Advantages include higher strength, lighter weight and faster cooling during the extrusion process.

Abstract: A method of producing corrugated sheets of thermoplastic material by supplying a softened film over an embossing roller to form first, second and third sets of parallel corrugations which radiate from a common center to define a plurality of star shaped cells and sandwiching the corrugated film between outer films to define pockets.

Abstract: A packaging tray for use with food such as meat or fish formed from a hollow plastics material board, the base portion (14) of the tray having holes (16) formed in the upper portion thereof and the holes having a lip (18) which is at least partly removed on the top side. The tray is preferably formed from corrugated plastics material sheet of a recyclable material such as polyolefin. The holes are star-shaped and channels are formed through the lip in the interstices between adjacent points of the star allowing liquor to drain into the interior of the board but not back out again.