The shearing machine is an important equipment on the uncoiling line, and the number of shearing strokes of the shearing machine largely determines the productivity of the uncoiling line. The shearing machine in the uncoiling line is generally different from ordinary shearing machines because the uncoiling line has the following special requirements for the shearing machine.

(1) High productivity. For an uncoiling line with a thickness of 3mm, it is required to cut 30-35 sheets per minute for a fixed length of 2000mm. For a fixed length of less than 500mm, it is required to cut 80 sheets per minute. Such high productivity is beyond the reach of a universal shearing machine.

(2) Full load. Many users of the unwinding line operate on 2-3 shifts, and the shearing machine cuts 10000 to 20000 times a day. A universal shearing machine cannot be used with such a load.

(3) High reliability. If the shearing machine in the uncoiling line stops, it will cause the entire uncoiling line to stop working. For users like car factories, the shutdown of one unwinding line can also cause several stamping lines to shut down. Therefore, it is required that the failure rate of the shearing machine in the uncoiling line should be as low as possible, and fault diagnosis and elimination should be relatively easy.

(4) The diversity of coil materials. The universal shearing machine determines the shear force based on ordinary carbon steel, and the materials used for coil materials include high-strength stainless steel plates, weather resistant steel plates, pickled plates, etc., in addition to lower strength galvanized plates, tinplate, color coated plates, and aluminum plates. The coil materials used in car production include uncoated cold-rolled sheet, hot-rolled pickled sheet, high-strength cold-rolled sheet, high-strength galvanized sheet, single and double-sided electrolyte coated sheet, single and double-sided hot-dip galvanized sheet, aluminum sheet, etc. Users of the unwinding line often have different requirements for the mechanical properties of the processed materials, so when designing and selecting a shearing machine, the applicability of the machine must be considered.

(5) Special cutting methods. Some uncoiling lines require the burr direction of the cut sheet to be upward in order to avoid scratching the surface of the sheet during stacking. Therefore, the blade holder of the shearing machine should cut from bottom to top. This type of shearing machine is called a down cutting type shearing machine. The cut sheet material falls onto the moving conveyor belt. In order to avoid tilting, it is required that the blade shape on the knife holder be in a herringbone shape, which is particularly necessary for sheet materials with shorter fixed length.