The slitting of hot rolled coils involves many processes line operators need to consider, one of which is how to handle the HR side edge scrap trimming. In efforts to minimise scrap to maximise yield, there are 3 main systems available to slitting lines to consider.
Using the right one is important to prevent downtime by correctly handling the side edge scrap trimming and the efficiency of the scrapping system is normally determined by the hot-rolled coil thickness the line will process.
The first system is a scrap winder. It pulls the side edge trimming scrap under tension from the head of the slitter in unison with the running line and winds it into a coil. Commonly they would run in pairs, either side of the slitting line to maintain uniform tension on the scrap trimming from the slitted coil. The trimming scrap is then wound into a coil which can be removed. The line operator must monitor the winder to maintain the tension of the scrap trimming.
This method works best for hot-rolled coils with a thickness range from 0.010 inches to 0.50 inch. If the trimming scrap is too thin then most likely the scrap will snap under tension, and if it is too thick it will be difficult to wind into a coil and not too efficient.
Chopping the scrap trimming is another method. The choppers are located directly after the slitter head with chutes for the scrap to run into. Lines with choppers usually run material 0.010 inches to 0.750 inches and are best suitable for thicker hot rolled coils. The scrap trimming when chopped can be easily transported and handled for onward processing.
The final system to handle side edge scrap metal trimming is with a scrap baller system. The head of the slitter pushes the trimming scrap into a collection pit.
After the hot-rolled coil has been processed on the slitting line, the scrap baller will pull the edge trimming scrap from the pit under no tension and uses a steel mashing roll to create a compact bobbin of trimming. The baller system is best suited for lighter gauge coils 0.005 inches to 0.187-inch thickness.
The baller system does need a large area for the pit, however, needs less operator input to manage and with zero tension means fewer scrap breaks.
Each system to handle hot-rolled (HR) side edge scrap metal trimming has its pros and cons. Factors such as the thickness of the coil being processed, space constraints of the slitting line and financial budget also need to be considered.
Tiger International Limited is one of the largest international purchases of HR trimming scrap metal, and producers can get in touch with us to discuss selling their scrap metal.