Tag: Exair_DW

Jack Frost, and Static, Just Will Not Let Go

Published on by Dave WoernerLeave a comment

As the weeks of March pass, we expect the weather to get better, but the last weeks of February has been brutal. Hopefully, Jack Frost will loss his grip as we move past the mid point of March. By the time this blog posts, it may be 60F degrees in Cincinnati, and I hope this blog is out of season. (Real time update – it will be 50F today)  In Ohio we had a fairly mild winter through December and January, but February was bitterly cold.  The bitter cold led to a few questions about static.

During cold weather the humidity in the air drops. This drop in humidity means that air can not dissipate static electricity as quickly as it does during warmer weather. Because static does not dissipate as quickly, industrial processes will create a much larger potential difference on rollers, winders, and web related products just to name a few. This potential will manifest itself in the static charges or shocks that we associate with rubbing your socks across a carpet floor. Getting into and out of your car can also be shocking experience. Shocks are one aspect of the static buildup, but the attraction and repulsion of static charges can wreck havoc on web applications.

If you have a process such as labeling, sheet feeding, or printing, that is jamming, curling, or tearing, you may have a static issue. But how can you be sure that static is causing your issue? A Static Meter! EXAIR 7905 Static Meter is a portable, non-contacting static meter that will allow you to accurately measure the static charge on large surfaces.  The meter will indicate surface voltage and polarity and is certified to NIST for accuracy and calibration traceability.

Static Meter
EXAIR Static Meter

 

Once a static problem is identified, EXAIR has a number of Static Eliminators that can be implemented to neutralize the static and restore your manufacturing process to proper operation.

Dave Woerner
Application Engineer
@EXAIR_DW
DaveWoerner@EXAIR.com

Is it Blue or is it White?

Published on by Dave WoernerLeave a comment

Last night I’m browsing around my favorite social media sites, and I’m flooded with images of THE dress which is clearly white and gold (and clearly over exploited). Even though everyone says it is blue and black. How do you get blue and black confused with white and gold? Turns out that science is involved. People much smarter than me have pointed out that this is simple optical illusion (see the photo below). I don’t think the people taking the picture meant to trick everyone, but I wouldn’t be surprised, if they did.

Here is another example

Color Letter
The blocks containing “A” and “B” are the same color

This optical illusion had me very concerned. Two of our product lines use a white label or a blue label to differentiate between products.

Take for instance the High Powered Cold Gun and the Standard Cold Gun. The labels are the similar, but one is white and one is blue.

Cold Gun Lineup
Standard Cold Gun (Left) has a white label High Powered Cold Gun (right) blue label.

The Standard Cold Gun will generate 1,000 BTU/HR of cooling, and The High Powered Cold Gun can generate up to 2,000 BTU/HR. of cooling. I would hate for someone to confuse the two units.

Or look at the Reversible Drum Vac versus the High Lift Reversible Drum Vac?

IMG_4590
High Lift Reversible Drum Vac (left) Blue/Black Label. Reversible Drum Vac (right) Blue/White Label

The High Lift Reversible Drum Vac will lift liquids up to 15 feet vertically. The Reversible Drum Vac can pump 55 gallons in 90 seconds but is limited to 9′ vertical lift.

Could these products be confused, if someone takes a photo with lighting from the back? Sure, they could given the correct conditions, but the labels also say the “High Power” or “High Lift”. I think we can still tell the difference between the products. Man, that’s a relief. Here is a link to another photo of the dress. I was tricked, clearly it is black and blue.

Dave Woerner
Application Engineer
@EXAIR_DW
DaveWoerner@EXAIR.com

 

“A” and “B” image courtesy of Rob Lee. Creative Commons License

 

 

Shocking Credit Cards Costs … In Manufacturing

Published on by Dave WoernerLeave a comment

Winter’s weather comes with a variety of problems. I hope that folks in the Northeast get a break from all this snow soon. In Cincinnati we have not had to deal with much precipitation this year, but it has been cold and gloomy for too long. Personally, I am ready for spring to come and to the see the flowers pop up. I’m also tired of the getting shocked every time I pet my dog. Also, his hair that generally falls everywhere is now stuck to the side of couch.

On a more serious note, the dry air of winter can have a significant impact on manufacturing processes. The same static that attracts dog hair to a couch will also attract dust on to a non-conductive substrate like plastic or glass. I was working with a customer this week who manufactures credit cards and gift cards with custom logos. They fell prey to the dry, statically charged air of winter which caused a quality issue during these winter months. To create the promotional cards, the company would first digitally print the logo on a PVC substrate. This substrate is then stacked to await lamination. As they pulled each sheet from the stack, a charge would build up on the surface which would attract any dust in the area. The dust needed to be removed before the last clear layer was applied or it showed up as ugly bumps on the card surface. This dust was nearly impossible to clean off and still maintain a good finish on the PVC substrate. They tried to wipe the material off with soft fabric, but the rubbing only increased the static while moving the dust around, not off the laminate.

1559 before
Laminating station two stacks of PVC substrate in the plastic bins
1559-photo
Laminating Station with the 110036″ Super Ion Air Knife installed

Using an EXAIR Static Meter, part number 7905, the customer measured 19.5 kV/inch on the PVC sheets before lamination. Because of this charge the customer installed a 36″ Super Ion Air Knife, part number 111036, above the lamination station. The operator would pull a sheet from the stack and pass it under the Super Ion Air Knife. After passing under the Super Ion Air Knife the charge on the sheet read 1.3 kV/Inch, and the dust was removed by the air blowing from the Super Air Knife. This dust removal drastically reduced their scrap levels. In the 3 months of winter, it was accepted that they would loss approximately 15% of all the cards they created do to blemishes on the cards. After installing the Air Knives, they only scrapped 3% of the cards they created. This scrap rate was even better than there summer production. The air knives will now be used year round.  The Super Ion Air Knife reduced scrap by 80%! Also, operators no longer tried to clean the dust with cloth, which allowed them to increase their production.

Dave Woerner
Application Engineer
@EXAIR_DW
DaveWoerner@EXAIR.com

What Size Pipe Should I Use?

Published on by Dave WoernerLeave a comment

Yesterday, I had a customer with a tough application for a Standard Air Knife. The customer was quenching individual 11″ x 11″ steel plates in oil after they had been heated to over 1,200° Celsius. Following quenching, the plate is pulled out of the oil with a fair amount of excess oil still attached. This excess oil is relatively hot and could be dangerous, if it drips from the plates as they are conveyed to the next process. The oil removed from the tank is also lost, so the tank needed to be refilled regularly. This oil added up to quite a large expense every year for this company. The customer installed (2) 12″ Standard Air Knives above the oil quenching tank to blow the oil off of the plate back into the oil quenching tank as the plate is raised out of the tank and in between the two air knives.

How the Standard Air Knife Works
How the Standard Air Knife Works

The customer called to express some disappointment about the air knife performance, I asked him a few questions about his application.

Q:What pressure is supplied to the air knife?
A: 100 PSI
Q: Where are you measuring this pressure?
A: That is our shop pressure and the pressure I’m measuring at the regulator.
Q: How are you connecting the regulator to the air knife?
A: We are using 10 feet of 3/8″ ID tubing.

At this point I suspected that the problem was in the compressed air supply line. To confirm this, I asked the customer to install a pressure gauge in the unused air inlet of the air knife. This pressure gauge read only 52 PSIG. The customer had a pressure drop of 48 PSI through the 10 foot of 3/8″ tubing, fittings, and valves that connected the regulator to the air knife.  The 12 inch Standard Air Knife utilizes 41 SCFM of compressed air when fed with 80 PSIG. In order to determine what to expect for a reasonable pressure drop, you could use EXAIR’s Air Data charts. According to EXAIR’s air data chart, for 1/8″ schedule 40 iron pipe, which has around 1/4″ ID (Which is very similar to the Inside Diameter of the 3/8″ tube) at 8 SCFM of flow the line will create a 18.6 PSIG pressure drop. When you try and shove more than 8 SCFM through the 3/8″ OD (1/4″ ID) tubing, you create a higher pressure drop. In this customer’s case it created a 48 PSI drop across the air line. This 48 PSI pressure drop was caused by the supply line as well as the fittings or valves used to connect valve to the regulator. This pressure drop limited the air knife to only 52% of its performance. In an application with a viscous fluid like oil , this drop in pressure led to lower force upon the steel plate and disappointing performance.

After getting the proper plumbing in place, the pressure drop was eliminated and the the Air Knives were operating at peak performance to remove the oil from the plates.

During the course of our troubleshooting, the customer also discovered Russ Bowman’s excellent video Proper Supply Plumbing for Compressed Air Products. In the video, our customer discovered the impact both the cross sectional area and overall length of compressed air piping can have on the performance of an air operated device.

The customer wanted to use a 12″ Air Knife to blow off the oil from the plates, which is a great application for the air knife. By properly plumbing the supply of an Air Knife, the customer contained hot oil, reclaimed quenching oil for future use, and maintained a clean shop floor. This installation was well worth the time and effort of installing the air knife properly. If the customer would like, we also have a Super Air Knife which will only use 35 SCFM and could help to save more compressed air. This savings of 7 SCFM may not seem like much, but it will have a significant impact on the energy cost of running his air compressor.

Dave Woerner
Application Engineer
@EXAIR_DW
DaveWoerner@EXAIR.com