Plastic drip dispenser has member contg. recessed passage - with flow resistance joined in housing by ultrasonically produced friction heat

摘要

Method is intended for producing a (horticultural) plastic drip dispenser comprising a housing with inlet and outlet at opposite ends and containing a member (2) without clearance of which at least one face is provided with a groove (7) with obstacles (e.g. zig-zag groove) forming a passage from inlet to outlet with a flow resistance such that, at a given inlet pressure, the liquid emerges as drips from the outlet. The component parts (housing and member) are formed in moulds and fitted together and subjected to a treatment to join them. This treatment consists of inserting this assembly in a mould and placing an ultrasonic vibrator rod against the assembly at the open end of the mould for a given time (0.1-0.5 sec). The frictional heat developed at the mutual contact areas produces the required join.