Btu Dual Hose

Cold Air Tool Cooling Permits Machining Without Coolant

Since 1983, EXAIR Corporation has engineered Intelligent Compressed Air® Products that provide unique solutions to common industrial problems. EXAIR's Cold Gun Aircoolant System is one of those products that provide a solution to an old problem. Heat build up on dry machining operations reduces tool life and machining rates. The Cold Gun Aircoolant System produces a stream of clean, cold air at 50°F (28°C) below supply air temperature. Operation is quiet and there are no moving parts to wear out. It will remove heat to prolong tool life and increase productivity on machining operations when liquid coolants cannot be used.

Many machining operations use mist coolants to cool the parts and maintain tolerances. However, there are problems associated with mists. The coolant is costly – with costs associated with the purchase and disposal of cutting fluids. Another problem that people are becoming increasingly more aware of is the worker related health problems from breathing airborne coolants or slipping on wet floors. EXAIR's Cold Gun is the alternative and can either completely eliminate the mist or greatly reduce its use.

Machining operations typically run all day and it is important that the Cold Gun be able to run for the duration, providing a steady stream of cold airflow. EXAIR's Cold Gun is non-adjustable to prevent freeze-up during use. Cold airflow and temperature drop are factory set to optimize the gun's cooling capability. It provides the maximum Btu/hr capacity for the amount of compressed air that is consumed.

The typical applications include:

• Tool sharpening

• Drill & cutter grinding

• Routing

• Plunge and form grinding

• Milling

• Surface grinding

• Drilling

• Tire grinding

• Band sawing

• Plastic machining

• Laser cutting

• Chill rolls

• Setting hot melt adhesives

EXAIR's Cold Gun offers some distinct advantages:

• Improves production rates

• Prevents burning

• Extends tool life - reduces breakage

• Improves tolerance control

• Prevents smearing of metal or plastics

• Finished part is dry

• Eliminates wheel loading

• Low cost

• Compact, lightweight, portable

• No moving parts - maintenance free

• Quiet

• No coolant cost

• No electricity

Need more cooling power? EXAIR's got it! The High Power Cold Gun produces twice the airflow of the standard Cold Gun, doubling the cooling capability. It produces cold air at 50ºF (28ºC) below the supply air temperature so the air is as cold as possible without freezing up. Two systems are available: the Model 5230 High Power Cold Gun with Single Point Hose Kit and Model 5330 High Power Cold Gun with Dual Point Hose Kit.

You might wonder how effective the Cold Gun really is. Recently, there was a long term study on the effect of refrigerated air on tool wear in wood machining conducted at the Forestry Products Department of Purdue University by Ms. Judith Gisip. The Purdue Study was under the direction of Dr. Rado Gazo (department professor) and Harold Stewart (professor at North Carolina State University and 35 years in wood machining research).

Wood is brutal on tooling. In metalworking, most of the heat goes away with the machined chip. Wood is an excellent insulator and doesn't conduct the heat away, which keeps it all there at the tool. Temperatures can exceed 800°C!

The extensive tests with the EXAIR Cold Gun at Purdue were conducted in a 70°F climate controlled room. They tested (4) 1/2" (12.7mm) two-flute cutters on a CNC router at 16,000 rpm. (22) sheets of 3/4" thick MDF (medium density fiberboard) were fed one at a time, cutting away 1/4" (6mm) depth of cut on each pass. Power consumption of the CNC was recorded (current draw increases as the tool starts to dull). When finished, the surface of the tools was examined using a scanning electron microscope. Machining with the Cold Gun's 20°F air reduced tool wear by over 21% compared to the results with no cooling.

How Much Can You Save?

A 1/2" two flute router bit for wood is approximately $58.

The 21% reduction in tool wear when using a Cold Gun is $58 x 0.21 = $12.18 savings per bit.

If you use (1) router bit per working day, the savings is $12.18 x 5 working days = $60.90 per week / $3,167 per year – And that's for one bit!

The overall analysis is that the Cold Gun can help to reduce tool wear along with increasing feeds and speeds without all the mess of liquid coolants.

About the Author

Gary Gunkel is Marketing Manager of the EXAIR Corporation.