Shear Lines

Shear lines (also called cut-up lines or cut-to-length lines) produce accurately cut-to-length sheets from coil stock. A shearline generally consists of an uncoiler, a roller leveller to remove coil set, followed by a feeding and measuring system, shears and finally a stacking device for the cut sheets. The two basic types of shear line are those using stationary shears and those using flying shears.

In a stationary-shear line the strip is stopped and then cut by straight shears. Feeding is by hump table (accumulates strip prior to sbearing to length) and gauge table, or alternatively by measuring feed rolls. This type of line is lower in cost and slower than flying-shear lines.

Flying-shear lines use moving shears to cut the strip as it moves continuously through the shear line. The shears are of two main types; guillotine shear and rotary drum shear. The guillotine shear is mounted on a moveable housing which moves forward with the strip while cutting and then returns to its starting position. The rotary drum shear utilises shear blades mounted on rotary drums above and below the strip. The shear blades are brought together as the drums rotate Rotary drum shears operate at very high speeds.

Information on the relative merits of each type of line for a given range of products may be obtained from equipment manufacturers or their agents.