Thermoplastics foam drinking beakers for vending machines - by ultrasonically welding together a preform of a flanged bottom portion and a top ring to give a deep rimmed cup

摘要

The beakers have a profiled rim. A breaker-shaped preform with flanged rim and a pre-formed profiled ring of a thermoplastics that can be welded to the foam material are charged to an ultrasonic welding installation and pressed under 10 bar, on an anvil, using an axially moving sonotrode. Ultrasonics is applied for 0.2-4.0 sec. and beaker preform and ring are welded together and suitably profiled by a further, adjustable, advance stroke of the sonotrode whilst the flange of the beaker is compacted to a density of 0.60-1.05 g/cc. Beakers with relatively high depth:dia. ratio can be produced i.e. the prod. is of more pleasing appearance than prior-art, rather squat, cups. The moulding is free of "flash" at the rim where a user's lips come into contact with it.