PRODUCT REVIEWS
On the level
Heinrich Georg Maschinenfabrik recently commissioned a new high-performance leveller at EMW Steel Service Center ( Neunkirchen , in the German Siegerland region ). The new machine enables EMW to add high-strength steel coils to its product range and boost its levelling throughput .
As its customers have been placing increasingly exacting demands on the flatness of higher-strength steel strip , EMW has equipped its No . 2 multi-blanking line with a new high-capacity roller leveller from GEORG . The new leveller replaces a machine that could process strip of 300 N / mm 2 yield strength at the maximum .
The main target of the project was to broaden the supply range of coils to include strips with yield strengths of between 600 and 1,000 N / mm 2 and thicknesses of between 1.0 and 1.5mm . EMW supplies hot-rolled coils – pickled or galvanized – and cold-rolled coils with inorganic or organic coatings .
GEORG supplied and commissioned the leveller in eight months from the placement of the order . Successful levelling of the first coils took place in mid-August 2020 . EMW issued the FAC as early as on 30 September 2020 . Since then , the machine has been continuously in use on a three-shift basis .
The semi-automatic quick-change system reduces the time needed for a cassette change from 25 minutes to 15 minutes .
The new roller leveller during assembly .
Strip operations
The new RM 55 / 17 / 7-6h – 1600 machine is equipped with 19 levelling roller sets of six-high configuration . All levelling rollers have a diameter of 50mm . The machine can process strips with surfaces as challenging as electrogalvanized steel sheet and grades for car body shells , for example .
“ The new roller leveller can handle material between 300 and 1,600mm wide . It is designed to level 0.4 to 3.0mm thick strip with tensile strengths of up to 700 N / mm ², yield strengths of up to 450 N / mm ² and elongations at break between 15 and 45 %. In the 0.4 to 2.0mm thickness range , it can process strip of up to 1,200 N / mm ² tensile strength , up to 1,000 N / mm ² yield strength and an elongation at break of 8 %. To cope with the challenging task of levelling high-strength materials , the machine features an exceptionally rigid frame and a distribution gear with output shafts arranged in three rows ,” GEORG told ISMR .
Particularly for thin strip , it is crucial that the rollers can be precision-adjusted with accuracy of repetition .
“ In the leveller , this is guaranteed by the four high-precision , low-backlash planetary gearboxes , which set the roller spacing , and seven adjustable wedges , which ensure accurate setting of the back-up roll assemblies ,” explained GEORG . “ The leveller comes with a semi-automatic quickchange system , which enables the complete levelling roller cassette to be replaced as one module without having to take apart the ball joint shafts .”
Cassette change times can therefore be reduced from 25 minutes to 15 minutes . For the machine to be ready for future flatness quality requirements in the 0.4 to 0.8mm strip gauge range , 21-roller cassettes are also now available .
The scope of supply for EMW comprised a new strip threading unit complete with threading table , a counter-bending roll and a conveyor unit for feeding the strip into the leveller . GEORG has integrated an existing crop shear between the threading unit and the leveller to further reduce cycle times in coil processing . “ The results obtained during the first months of operation have shown that the new machine can level a much wider range of products than the previous one . On top of that , flatness of all products levelled has been 50 % better than specified in DIN EN 10131 ,” said GEORG .
Torsten Brüggemann , the production manager of EMW Steel Service Center , summarised his experience with the new machine so far : “ We have been able to further improve the quality of all products from our range . Coil flatness is no longer an issue during our production meetings . The new machine has even taken over coils from our bigger machines . This not only saves costs , but also provides us with more flexibility in production and , consequently , we can produce more ,” he said .
ISMR March 2021 | sheetmetalplus . com | 43