Sawing in Looms

The process of sawing in the looms is complemented by a pulp of water, whitewash and grit, poured continuously over the load, for optimization of the blades cut and cooling.

The load can be composed either by only one block or married blocks, the block of small width being called “cork” and connected to the larger block and used as load complement in some sawing. The blocks can have up to 2 m height, corresponding to the admitted maximum width for plates in the polishing-machines, and up to 4 m length.

Ideally, blocks with different heights, different material hardness and plates with different thickness should not be sawed in the same load, because of the differential consuming of the blades, vibration of the equipment, ill flattening of plates and even spalling of the material.

Still inside the quarries, the shaping or preliminary cutting of the blocks, through monoblade equipment or stoning, optimizes later sawing in the loom, making it possible the standardization of block dimensions, better coupling or joining (plumbing) of the blocks in the load, higher productivity per cubic meter and reduction of sawing losses (husks) derived from the sawing.

The steel blades of the loom are manually tensed, whether through wedges, or automatically by hydraulical tension. Weak tensioning implies longitudinal undulations of the blades, which produces bad planishing of plates and minor cut speed. Extreme tensioning originates transversal curving of blades, producing furrowed plates.

The most modern looms make use of equipment’s that control automatically the feeding and mixture of the abrasive pulp, once the feeding must be constant, and viscosity should
not be exceeding.

An average of 32 sq./m of plates with 2 cm of thickness, or 49 sq./m with 1 cm of thickness are divided by cut, for each cubic meter of stone sawed in the loom. Depending on the best sawing of the block or blocks, up to 35 sq./m of plate with 2 cm of thickness, and 55 sq./m of plate with 1 cm of thickness can be reached.

The raise speed in cutting for steel blade looms is around 20-30 cm/h for marbles and 2 cm/h for granites. The raise speed in cutting for diamond blade looms should go up to 50-60 cm/h in marbles and 4 cm/h in granites.

Most modern looms, including Brazilian ones, with great loading capacity and high speed movement of the blade set, produce up to 5.000-6.000 sq./m month in granites and up to 8.000 sq./m month in marbles.
granitos e de até 8.000 m2/mês em mármores.