Tag: stamping

The power of the 2” High Power Flat Super Air Nozzle in a blow-off application

Published on by John BallLeave a comment

A stamping company contacted me for help in their ejection blow-off system.  Their operation consisted of a punch press that would form two 8” X 8” triangles from a square piece of metal.  The operation of the punch press was to cut the square piece diagonally at the same time forming the outside edges of the triangle.  At the end of each stroke cycle, the formed parts would then be blown off the die with compressed air.  The blow-off system consisted of two pipes, one that was a ¾” NPT pipe and the other that was a ½” NPT pipe.  They both had the ends of a long nipple flattened to concentrate the air flow.  EXAIR has reduced air use, saved money, and lowered noise levels for many similar applications by replacing open blow-off devices with our engineered air nozzles.

In giving me more details about their operation, the system had a timing sequence that controlled an actuator. When the cycle was complete, the actuator, located below the tabletop of the punch press, would open and send compressed air through both pipes.  The positions of the blow-off pipes were designed to eject one part off the side of the die and the other part off the front of the die into a collection chute.  (Reference the picture below)  They were having issues when their blow-off system wasn’t consistently able to eject the 1 lb. part completely off the die.  In manually having to remove the parts, it would cause an unsafe environment as well as a slowdown in operations.  They found that EXAIR manufactures Intelligent Compressed Air Products and wondered if we could help.

Blow-off Setup
Blow-off Setup

With a lack of restriction at the end of the pipe, the air pressure will drop quickly as it travels through a relatively long length of pipe. The actuator, which was more than 3 feet away from the end of the pipes, had a line pressure of 90 psig (maximum that they could supply).  By the time the compressed air reached the ejection site, the pressure was much lower; thus, not quite removing the part from the die.  An example that I like to use is a garden hose attached to a spigot outside your house.  As you open the spigot, water will flow out of the hose at a slow velocity; not very strong, that is the same as air through an open pipe.  When you place your thumb partially over the end of a garden hose you restrict the flow and increase velocity. Engineered nozzles from EXAIR work the same way.  They restrict the flow at the nozzle, increasing the pressure for a more effective velocity and blow-off force.  Neal Raker wrote a great blog for EXAIR referencing how the nozzles work; called “What’s in a Nozzle?”

HP1125 2" High Power Flat Super Air Nozzle
HP1125 2″ High Power Flat Super Air Nozzle

I recommended the model HP1125, 2” High Power Flat Super Air Nozzle. It has a 2” wide air stream to allow more contact against the side of the triangle edge.  It has a force of 2.2 lbs. at 80 psig which is more than enough to eject the 1 lb. formed part.  As an added benefit, it only has a noise level of 83 dBA which is magnitudes more quiet than the open pipe.  Also in using the engineered nozzles, they were able to use much less compressed air in their blow-off, saving them over $1,000/year.  If you find that your open pipe blow-off is too loud, not effective, or uses way too much compressed air, you should contact an Application Engineer to see which engineered nozzle would best suit your application.

John Ball
Application Engineer
Email: johnball@exair.com
Twitter: @EXAIR_jb

Light Duty Line Vac Conveys the “Slugs” from a Die Punch Application

Published on by Neal RakerLeave a comment

At EXAIR, we get asked a lot of interesting questions about what our products can do. One of them that occurs with some frequency is, “Can your Line Vac convey slugs from a stamping operation?” The answer is usually yes as “slugs” (the material punched out of a sheet of stock to create a hole) are well suited in size, shape and weight to be conveyed effectively with the Line Vac product. We are used to this question from folks who are processing various types of metal sheet. The slugs tend to build up within their tooling and basically get in the way, if not even jam up the tooling from time to time. So getting rid of them from the process becomes a necessity that is, many times, not addressed during the tool making process.

Recently, we had another customer with this same kind of problem with foam. They were processing a foam sheet by punching a many holes in it which generated the waste stream you see above. Little pieces of foam about 8 – 10 mm in diameter and about 40 mm long. As you probably have guessed by now, the area that was set up to receive these renderings quickly became loaded full with the foam slugs. The customer needed to find a way to remove the slugs to a remote area so the receiving container could be switched out easily without stopping production. The original container was small, plastic bin about the size of a kitchen garbage can. The new receiving container was a large cardboard box that typically goes by the term Gaylord. The customer needed to set the Gaylord about 3 – 4 meters away from the die punching area. This is where the EXAIR model 130300 (3” Light Duty Line Vac) comes into play. The customer fabricated a chute that was positioned under the area to catch the slugs. The chute transitions to accept the 3” Light Duty Line Vac for connection at the bottom. Then, a 3” hose is connected to the output side of the Light Duty Line Vac so it could blow the slugs over to the Gaylord.

P1060775
Foam Slugs From Die Stamping Process

The customer chose the Light Duty Line Vac because it uses less air than a comparable size of our Standard Duty units. They didn’t need a tremendous amount of suction power due to the light-weight nature of the slugs. They also wanted a 3” unit to make sure none of the product would get caught anywhere within the conveying stream.

With the new Light Duty Line Vac installed, the operators do not have to spend as much time tending to the emptying of the previous, small containers that had to be used due to their size for fitting into the catch area. For an application where thousands of these slugs are produced in an hour, the productivity gain was significant. The customer didn’t place an exact value on the gain, but are considering this method for other, similar processes they have in the plant.

Neal Raker, International Sales Manager
 nealraker@exair.com
@EXAIR_NR

 

Long Super Air Knives Help Dry Oil Pans

Published on by exaircorpLeave a comment

Last week I was contacted by a local machining company who was stamping oil pans for a large automotive manufacturer. Stamping, also referred to as pressing, is an industrial machining process where a flat material, like sheet metal, is placed into the stamping press and a press die stamps down to form a specific shape or mold.

metal stamping
Example of Metal Stamping Machines

As the oil pan exits the stamping press the parts are sent through a water rinse to remove any particulate and then hung from a drying rack. After the parts are dry they are sent to a paint booth then an oven for the paint to cure. They were beginning to see reject parts after the curing process due to residual water droplets being present which caused the paint to bubble or streak in this particular area. As a quick fix, on each side of the drying rack they ran compressed air to long lengths of 1″ PVC pipe with approximately (21) 1/8″ drilled holes spaced about every 4 inches to try and dry the parts more efficiently. While this did improve the dry cycle time, they were still seeing the rejects due to gaps in the airflow continuing to leave water drops. Another concern was their compressed air usage as they have a large number of rotary presses requiring compressed air so this particular application was, as the customer stated – “getting whatever air is left”, and potentially starving other processes of required air.

Once again EXAIR had the perfect solution, the Super Air Knife. The Super Air Knife produces an even, high velocity curtain of air across the entire length of the knife. Extremely efficient, the unit uses only 1 part of compressed air while entraining 40 parts of surrounding, ambient air. In this particular application, I recommended the customer mount one 84″ knife on the front and another 84″ unit on the back of the rack, allowing the parts to pass through the laminar airflow removing the excess water from both sides of the part.

SAK
Lengths up to 108″ in single piece construction.

Addressing the compressed air usage – each 1/8″ drilled hole is going to consume roughly 21.4 SCFM @ 80 PSIG, so for a quantity of (21) drilled holes, the total would be 449 SCFM per PVC pipe. In contrast, an 84″ Super Air Knife is going to consume only 243.6 SCFM @ 80 PSIG, or just a little over half of what they are currently using!

Justin Nicholl
EXAIR Corporation
justinnicholl@exair.com
@EXAIR_JN

 

Metal Stamping Machines image courtesy of Sam Beebe – Creative Commons License