Roll slitting, also called rewind slitting or log slitting, is a shearing operation that cuts a large roll of material into narrower rolls. The log slitting terminology tracks back to the olden days of saw mills when people would cut logs into smaller sections. By today’s definition, slitting is a process in which a coil of material is cut down into a number of smaller coils of narrower measure. Potential work pieces are selectively thin (0.001 to 0.215 in.) and can be machined into sheet or roll form. Slitting is considered a practical alternative to other methods due to its high productivity and the versatility of materials it can manage. Rewind slitting involves rewinding the material through a number of knives to form narrower rolls of materials. The machine used is called a slitter rewinder, a slitter or a slitting machine – these names are used interchangeably for the same machines.
The splitter usually consists of three main parts, an uncoiler, splitter, and recoiler. The material is fed from the uncoiler, through the nip between the two circular cutting wheels (one on top and another underneath) and then re-wound in slit pieces on the recoiler.
When the term “slitter rewinder” or “slitting machine” is used to describe the machine, the three parts are referred to as the unwind, the slitting section and the rewind. Slitter rewinders are normally used to slit plastic films, paper and metal foils. The unwind is either braked or driven to maintain accurate tension in the material. Some machines have a driven unwind which reduces the effect of inertia when starting to unwind heavy rolls or when the material is very tension sensitive.
The slitting section has three main options:
The rewind section also has options. The main type is centre winding using differential rewind shafts. These shafts are becoming universal on most slitting machines. The differential shafts ensure an even tension across the full width of the material. Closed loop control of the winding tension using feedback from load cells provides the total tension control system required for running tension sensitive materials. Precise and accurate tension control is the key to good roll slitting. Modern machines use AC vector drives with closed loop feedback from AC motors. When used with the correct control algorithms, they produce excellent results with the minimum of maintenance, just like the real solution hereunder provided by GTAKE for its end customers.
In this case, we used a GK600 series general purpose VFD for the pull roll motor, a GK820 high performance AC motor drive for knife roll motor, and coordinate the speed of the two motors. In this system, the inverter GK820 plays a critical role to ensure the precision of the finished products. Following lists some outstanding advantages of GK820 in the roll slitting
Refer to the picture also the video. Contact us today when you are the involved in a similar project.
GK820 is the high-performance series which covers an entire range of applications, particularly for demanding ones that require precise speed control, torque control and fast response, etc.
