The component being produced is a two-part assembly, manufactured from ABS material, and which has a combination of inner and outer chambers plus an over-moulded outer soft TPE (thermoplastic elastomer) sleeve. The parts are joined by two simultaneously-welded energy director joints in a single weld cycle. When completed, the component duty cycle has to withstand internal and external leak tests of up to 10 bar, and twist torque strength separation tests.
The new system, commissioned by Hozelock to produce these parts, is configured as a free-standing solution with an integral workstand. The assembly machine, designed and built by Telsonic UK in Poole, incorporates a four-station electrically-operated rotary table to allow the operator to manually load component parts from tote bins located at the front of the machine, while the machine welds the components together. The finished parts are then automatically removed at the eject / reject station.
The adjustment sleeve assemblies are ultrasonically joined at the welding station using a Telsonic USP750E press, powered by a 20kHz 2.4Kw MAG generator and SE2024S converter, together with a hardned steel sonotrode for high volume welding. The process is controlled by Telsonic’s Telsoflex software, via a touchscreen system. This provides full electronic pneumatic proportional valve control, access to a selection of multiple weld recipies, and a selection of weld modes including distance, absolute, energy, time, Pmax, amplitude and pressure profiling.
The ultrasonic system monitors each weld against a set of tightly toleranced pre-determined weld parameters, and the machine also monitors part presence and correct part positioning sensing prior to welding. A pick and place unit delivers welded parts to an output area and any rejected parts are segregated into a separate reject chute. A green / red light system is used to inform the operator if parts are misplaced or missing prior to the weld cycle to enable part recovery. Machine throughput is over 1,000 parts per hour.
Telsonic UK worked closely with Hozelock engineers. A testament to this long standing working relationship is the fact that Hozelock’s original ultrasonic welding assembly machine, designed, manufactured and supplied by Telsonic UK in 2013, is still in full production today. Development of the optimum joint design was undertaken, including tests to ensure the TPE overmould was unaffected by the weld process and ensuring the quality and consistency required for the finished product. Pre-production batches for testing were produced in Telsonic’s laboratory ahead of the machine build.
The production machine offers a simple, ergonomic and cost effective solution to the production of what is to be a high volume product for Hozelock, Telsonic concludes.
