McDermott Welding and Fabrication of Kersey, Pa., designs and fabricates fully-automated parts oilers (APOs) used in the manufacturing of a wide variety of machined and profiled steel parts in the automotive industry. The parts McDermott Welding and Fabrication makes range from small sprockets and drill parts to large converting rods and transmission gears.

Its automated parts oilers apply rust inhibitors to parts as a necessary as a final step in the parts manufacturing process. They complete the finishing of powdered metal parts, and add protection for packaging and shipping.

Due to the wide range of parts and part sizes, McDermott Welding and Fabrication needed a way to remove the excess rust inhibitor from the parts. T.J. Nesbitt, engineering manager for the company, said that the old equipment it used to in apply rust inhibitors left a lot of oily residue, meaning that the parts were shipped in a pool of rust inhibitor. Another problem was that the robot couldn't pick up the parts because of the amount of oil on the part. While necessary, the application of the rust inhibitor also was causing quality problems.

To solve these problems, McDermott Welding and Fabrication contacted JetAir Technologies of Ventura, Calif., which provided McDermott Welding and Fabrication with a JetLine Air Knife Blow-off system, run by a JET-2 high-speed centrifugal blower. Instead of the traditional “continuous gap” air knife, the JetLine system uses a manifold-based system that has a series of stainless steel, precision-machined ½ in. nozzles inserted into a stainless steel tube. The custom JetBlast nozzles create a more focused, higher velocity pressure flow that is highly effective in blowing off the excess oil.

“The air nozzle manifold works perfectly for this application. The excess oil falls into a false floor and is recycled back into the first zone where the oil is sprayed onto the parts,” Nesbitt said.

“We also put a hood over the top to let some of the oil and mist to go up the exhaust pipe into a mist collector to come back into zone one. At the very bottom of that zone is an oil container with a float switch that will shut it down if the oil gets too low.

“In the blow-off zone, we have four different air knifes: below and above and two on each side to get the side profile. Between each zone we have rubber curtains and access panels to clean out the spray zone. We have two larger access panels in the blow-off zone because we've gotten into making bigger parts,” Nesbitt added.

The JetLine's Blow-off system is run by a JET-2 high-speed centrifugal blower using direct-drive technology.

The impeller fan is mounted directly to the motor shaft, eliminating the need for the belts, pulleys, tensioners and spindles that typically are required by traditional, belt-driven blowers.

The company said it also eliminated the costly and time-consuming maintenance that typically is required on the additional parts, so it found increased efficiency in the operation of its automated parts oilers.

Quality also improved because McDermott Welding and Fabrication can control the amount of spray.

“Now we have control over the spray and the volume of the rust inhibitor solution on each piece, allowing us to pass along the time and cost savings to our customers,” Nesbitt said.

The direct-drive technology has the JET-2 controlled by an Allen Bradley PowerFlex 70 variable Frequency Drive (VFD) that provides flexibility and control in operating the blower. The VFD is controlled through human interface module that McDermott Welding and Fabrication mounted directly to the control panel of the automated parts oilers. The human interface module enables push-button control of the blower, and allows for rapid increases and decreases in speed.

Nesbitt said that McDermott Welding and Fabrication can now “dial in” the speed and pinpoint the exact air flow and volume needed for each specific, individual application used with the automated parts oilers.

The JetLine Air Knife Blow-off system has a quick payback, Nesbitt said.

“Before we got the JetLine Air Knife, the operators would put parts in perforated containers, then set the on a drip table to allow the excess oil to drain. One customer's parts alone provided a payback for this equipment. The operator never has to touch the parts, plus it saves on rust inhibitor,” he said.