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COOLANT

Proper saw performance starts with proper coolant practices and ASKO Hunter saw blades perform at maximum efficiency under such conditions.

The coolant medium is usually water. Its function is:

• To quench the saw chips as they are produced.
• To blow them away, preventing them from accumulating between the teeth.
• To cool the teeth, preventing softening.

We recommend a minimum pressure of 350 psi (24.5 kg per square cm) to achieve the water speed and momentum necessary to penetrate the air barrier (high velocity turbulent flow) which forms around the saw blade at normal operating speeds.

For example, a 72" diameter (1,828 mm) hot saw blade with a pitch of 1"(25.4 mm) has 226 teeth on the circumference. Thus, at a speed of 25,000 SFPM (7,620 SMPM.), 5000 teeth pass by every second (22 revolutions per second ).

This illustrates the need for proper volume, pressure and direction of the water.

The location of the water nozzles should be adjustable as the diameter of the saw blade is reduced due to reconditioning. They should also be staggered on each side of the blade so that they do not blow against each other, and be located so as to direct the water onto the teeth as soon as possible after they exit the cut.

Under no circumstances should the water nozzles be directed into the saw cut zone. Doing this results in quenching the cut making it more difficult for the saw blade to perform as designed.

To minimize the amount of water carried over into the saw cut, baffles should be provided, inside the saw blade guard of the machine. This will sweep the water, after cooling, away from the teeth and toward the center of the blade.

Some users install an air hose at the exit end of the guard to blow water away from the saw cut.

Water pressure and volume on both sides of the saw blade must be the same.

Unequal volume and pressure results in unequal thermal expansion of the blade, causing saw blade run off. Apart from producing a bad cut, the blade may dish and fail in operation.

We again emphasize that good water practice will increase "in service" life and productivity. It will minimize cracking and lower overall cost of the sawing operation.

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