PAINT & POWDER
“ The secret of the especially high powder content in the ‘ soft cloud ’ is that it is expelled from the guns with relatively little air and actually rather slowly . This means the robot can get in closer , the material has more time to spread over the surface and it has better adhesion there ,” explained Mr . Wendt . This optimises the application of the powder , speeds up the coating procedure and prevents a significant amount of powder being wasted .
“ Although powder application does still entail losses , it was possible to lower the cost of powder coating per door panel by a considerable amount because the transfer efficiency in the coating process has been markedly improved and unproductive colour change periods have also been eliminated ,” Mr . Ritterbach summed up with satisfaction , because this had been exactly what the prognosis had promised to deliver . Powder consumption was analysed in great detail and has been further improved . In particular , the programming of robot movements still offers major potential . “ If you consider that even now a first-pass transfer efficiency of 60 % is already being achieved , even though our doors have cut-outs , patterns of holes and similar in the way of decoration , then our experience of many years shows that such results can only be achieved using HDLV technology ,” added Mr . Wendt .
For trained , professional staff , a conversion like this is no problem
It is only economically possible to turn out 40,000 door panels a year in small batches and with very high quality requirements by utilising a high level of automation , in conjunction with precisely defined procedures ensuring production processes are reproduced within the tightest of tolerances . It is essential for all components within the plant to provide excellent reliability , for them to be easily accessible and for maintenance intervals to be as long as possible in order to keep downtimes to a minimum , and ensuring that planning can handle the entire production process – especially when multiple coating is involved . Simple , undemanding control , rapid set-up and cleaning , and resource-saving operation round off the list of requirements for ‘ smart-factory ’ production .
The new powder coating system at OBUK has only been in operation a few months so far , but the procedures are already firmly in place . Ask any of the operations and equipment managers whether the investment of around 2 million euros in the latest , robot-assisted technology has fulfilled expectations , and the answers will be multi-faceted , but consistently positive .
“ When you have employees like ours who really know their powder coating , then a conversion like this is not going to faze anyone . On the contrary , the touch screen control for the system is highly intuitive and doesn ’ t need a lot of training . The way the process is portrayed on the screen is almost self-explanatory .” For operations manager Henrik Wendt , ease of production planning is of key importance . As an example , he spoke about the maintenance periods for the Encore HD pumps , which undergo heavy stresses . “ The pinch valves for the pumps are the only components which suffer from wear and , even in spite of the stresses they have to endure , they are still good for 15,000 colour changes . To be absolutely sure , we replace them after 12,500 , but then we never have a single one wear out . Even when faults do occur somewhere in the system , the signs are always there in advance .”
More than 15,000 high-quality colour changes have been made since the plant was commissioned at the end of January 2018 . After only a few short weeks , trust in the state-of-the art Nordson powder coating system had grown to such an extent that the pre-existing coating system , initially retained as a fall-back alternative , was deactivated entirely . It has now been dismantled and re-installed at one of OBUK ’ s subsidiary plants , where it will no doubt remain in use for many years . There is one feature of the old system though which is missed by OBUK employees on these cold February days - the enormous amount of heat it used to generate , “ On hot days in summer , it has been up to 40 ° C in the production hall , but in winter it was great – the new one is extremely energy efficient and it ’ ll never match that .”.
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36 SEPTEMBER 2021 read online : www . surfaceworld . com