Abstract: A non-releasable mechanical join useful for permanent joins of plastics material cartons is formed by a row of a plurality of engagement tabs interlocked in a complementary row of slots. The engagement tabs have heads able to passthrough the slots in one direction but unable to return in the other direction. The tab heads may be formed as arrowheads, the barbs of which act against edges of the slots to disallow withdrawal. Suitably, the leading edges of the slots ar convexly arcuate towards the approaching arrowheads. This may help to provide secure engagement. The greater the number oftabs and slots, the greater may be be the permanence of the join.

Abstract: Modular display booth units are made from an upstanding bent sheet body portion located at its top and bottom in respective depending and upstanding lips of counter top and tray portions. Inside the body portions, rails extend from side to side. Hooked ends latch into latching apertures in the side wall and the side wall of any adjacent unit to link them together. Special angled joining units are provided to allow the units to be joined to form elongate assemblies of varying configuration.

Abstract: A sandwich board is made of sheet plastics material such as polyethylene. The panels are inhibited from warping by inturned flanges along the edges. Along the rising edges the flanges may be permanently inturned by means of a reverse bend. Along the upper edge the flange may be hinged through double coined lines. A lower flange may also be hinged inwardly through double coined lines for rigidity. Braces may be provided on back panel surfaces for rigidity especially on large sandwich boards. The panels may be slightly offset from one another so that the inturned flanges internest. The outer surfaces of the panels are coated over the whole surface with an adherent ink which allows for later printing of information using cheaper conventional inks or paints.

Abstract: A non-releasable mechanical join useful for permanent joins of plastics material cartons is formed by a row of a plurality of engagement tabs interlocked in a complementary row of slots. The engagement tabs have heads able to pass through the slots in one direction but unable to return in the other direction. The tab heads may be formed as arrowheads, the barbs of which act against edges of the slots are convexly arcuate towards the approaching arrowheads. This may help to provide secure engagement. The greater number of tabs and slots, the greater may be the permanence of the join.

Abstract: A re-usable, recyclable, reversible carton is made from recyclable plastics material and is formed from a carton blank adapted for erection without the need for additional closure devices such as glue or staples. The plastics material may be polyethylene and printing on at least one surface may be by use of UV inks on a roughened surface with a view to maximum longevity of the printing. The carton is erected from a knock-down carton blank having releasable engagement tabs and slots to releasably maintain the carton in an erected condition. A two part lid is provided, each part of which may be folded down the side of the carton to allow for the possibility of using the carton for open storage.

Abstract: A reusable, recyclable carton is made from recyclable plastics material and has a closure which does not require glue, staples or other non-recyclable closing elements. The plastics material may be polyethylene. The carton is erected from a knock-down carton blank having releasable engagement tabs and slots to releasably maintain the carton in an erected condition. A two flap lid is provided, the flaps meeting on a line joining opposing walls of the carton. A flange rises from each of the opposing walls adjacent the joining line of the lid flaps. The flange is joined to its respective wall along only part of its length so that it has free ends. The flange may be bent over to overlie the lid flaps and its ends may be tucked into slots in the lid flaps for that purpose.