The production of Wet Cast concrete paving units with complex decorative edge shapes has traditionally required operators to remove cured products from their moulds (de-moulding) by hand and to stack the finished product onto pallets by hand. A study utilising postural analysis of these operations taking into account the weights of paving units involved some of which exceeded 25kgs. Revealed excessive flexing and twisting of the trunk, uneven loading of the knees and at times excessive exertion according to Borg’s rating system. Whilst retraining in correct postural methods has produced positive results and fewer manualhandling accidents, it was concluded that an automated solution had to be developed. An automated solution was needed to remove undesirable body movements but retain all of the agility associated with human activity capabilities of: product inspection, zero size changeover time, rejection of faulty product and a fast cycle time of 6 seconds per paving unit. A new concept of de-moulding was developed utilising three axis linear motion, edge compliance and a Robot working in synchronous action with the linear motion device. A vision camera for inspection purposes with at least pixel level resolution was developed to work in conjunction with a second Robot working within the movement arc of the first Robot. This second Robot rejected any camera inspection failures via a software handshake and stacked the paving on to pallets. The robotic solution provided an agile tool to enable the application of lean concepts by reducing, manpower, material waste, energy waste, from a relatively unsafe environment and provided a platform for further implementation of more advanced production planning methods.
SMED, Bar Code Technology, Lean and Agile, Process Map