Tag: PVC

Gen4 Stay Set Ion Air Jet Solves Printing Problem for PVC Manufacturer

Published on by Tyler DanielLeave a comment

We have mentioned here on the EXAIR Blog numerous times just how bad static can get in cooler, dryer regions with low humidity. The amount of moisture in the air is expressed as relative humidity. This value is given as a percentage of water vapor in the air, compared to how much it could hold at that temperature. In conditions of lower relative humidity, static charges build up much easier. When the relative humidity is high, there’s a higher concentration of water molecules present in the air. These water molecules “coat” the surface of the material, allowing electrons to move more freely and form a layer over the material. This layer of water molecules acts like a lubricant, reducing the forces that cause static to generate. There are many applications that static may only pose an issue once the climate changes. 

This could lead one to deduce that tropical climates don’t experience static, given the high humidity present in these areas. While it may be LESS common to experience static troubles in humid conditions, it’s far from impossible.

Such was the case during my recent visit with our partners in Costa Rica. A client of theirs that handles a variety of extruded PVC pipes and shapes was having some problems with a printing process. In their line, after the pipes are extruded, they must mark a batch code and company name on the outside of the pipe. On some days the residual static charge is so high that the ink won’t properly adhere to the outside of the pipes.

A process that should be automatic was requiring them to station an operator nearby to keep an eye on the printer. When issues arise, they must stop production, clean the marking off, and run it back through again. They don’t have the man-power to allocate a person to stand there and monitor things continuously, so this has led to some batches going out marked wrong and leading to rejection and subsequent return.

Fortunately, EXAIR has a wide variety of products designed specifically for use in treating industrial static problems. After checking out the application, it was clear that one of our Ion Air Jets was going to provide a great solution for the customer. Since the specific location of the marking varies depending on the diameter of pipe, they needed something that could also be adjusted. I recommended our Stay Set Ion Air Jet to be installed just prior to the printing head and directed onto the pipe where we’re to apply the marking.

After installation, they continued to monitor closely for a few shifts and managed to make it through a complete day without any rejected material. They no longer have a need to monitor this step in the process and can free up personnel for more important tasks in the facility.

As winter draws to a close, don’t assume static will just automatically go away when the warmer temperatures of spring and summer arrive. In some cases, as was in this application, static can be present despite humid conditions.

Tyler Daniel, CCASS

Application Engineer

E-mail: TylerDaniel@EXAIR.com

Twitter: @EXAIR_TD

Custom Pneumatic Conveyors for Unique Applications

Published on by John BallLeave a comment

EXAIR’s Air Operated Conveyors, or Line Vacs™, provide an efficient method of converting ordinary pipe, hose, or tubes into powerful in-line conveyors.  To accommodate the wide variety of unique problems, EXAIR has the ability to customize and tailor-make Line Vacs with different specifications.  Certain processes may require customizations like unique sizes, shapes, and materials in order for the product to be a perfect fit for their system.  EXAIR will work in collaboration with our customer to fabricate the best possible Line Vac solution for easy and efficient conveyance.

I worked with a customer to design a special Line Vac.  They needed 3” ANSI 150# flanges on a 3” PVDF Line Vac.  So, we had a special material with special ends to fit their specific needs.  The PVDF with Hastelloy hardware was for chemical resistance, and the flanges would mount into their piping system.  As with many of our Line Vacs, we can turn a normal piping system into a conveyance system for waste, parts, evacuation, or bulk materials.  For this customer, they needed a backup system for a fume hood.  With electrical vacuums and blowers, loss of power or motor failures can cause a momentary lapse in fume removal.  Since the chemical material that was used in the hood was dangerous, they needed a reliable source to extract the fumes.  The Line Vac does not have any moving parts or require electricity.  Line Vacs only use compressed air or gas to make them operate.  For this customer, they attached nitrogen to the special Line Vac to operate when there was a power failure to protect the workers in the area. 

With the EXAIR design, we can alternate connection types.  For example, we can add a threaded end to connect to pipes on one side while having a slip-on end for hose connection.  In situations where the Line Vac requires a specific flange mounting option, EXAIR can accommodate.  EXAIR stocks 316SS Sanitary Flange Line Vacs, but we have done ANSI or DIN flanges as well.  For applications where stock aluminum, 303, or 316 stainless steel won’t work, alternate materials like PVDF, PVC, or PTFE can be utilized.  Even in extreme environments, EXAIR can produce both heavy duty and high-temperature iterations to handle even the toughest materials or conditions.  Other details, like particular hose sizes or pipe threading, can be specified to us.

Stock Line Vac models include standard, heavy duty, light duty, and sanitary flange.  All versions can be customized to meet customers specific needs.  All Line Vacs are CE-compliant and OSHA-safe.  For help solving any specific conveyance problems that you may have, please contact an Application Engineer at EXAIR.  We look forward to your challenge.    

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

Is PVC Pipe Alright to Use with Compressed Air?

Published on by Brian FarnoLeave a comment

A question arises every now and then on whether or not PVC pipe, yes the stuff from your local hardware store that says it is rated for 200 psi, is safe to use as compressed air supply line.   The answer is always the same,  NO! OSHA agrees – see their statement here.

Schedule 40 PVC pipe is not designed nor rated for use with compressed air or other gases.  PVC pipe will explode under pressure, it is impacted significantly by temperature and can be difficult to get airtight.

PVC pipe was originally designed and tested for conveyance of liquids or products that cannot be compressed, rather they can be pressurized.   The largest concern is the failure method of the piping itself.   When being used with a liquid that cannot be compressed, if there is a failure (crack or hole) then the piping will spring a leak and not shatter.   When introducing a compressed gas, such as compressed air, if there is a failure the method ends up being shrapnel.  This YouTube video does a good job of illustrating how the pipe shatters.

While it may seem that it takes a good amount of pressure to cause a failure in the pipe, that is often not the case.  I have chatted with some local shop owners who decided to run PVC as a quick and cheap alternative to get their machines up and running.

They each experienced the same failures at different points in time as well.  The worst one was a section of PVC pipe installed over a workbench failed where an operator would normally be standing. Luckily the failure happened at night when no one was there.  Even though no one got injured this still caused a considerable expense to the company because the compressor ran overnight trying to pressurize a ruptured line.

Temperature will impact the PVC as well. Schedule 40 PVC is generally rated for use between 70°F and 140°F (21°-60°C). Pipes that are installed outside or in non temperature controlled buildings can freeze the pipes and make them brittle.

If you haven’t worked with PVC before or do not let the sealant set, it can be hard to get a good seal, leading to leaks and a weak spot in the system.

The point of this is the cheapest, quick, and easy solutions are more often , the ones that will cost the most in the long run.

If you would like to discuss proper compressed air piping and how to save compressed air on your systems, please contact us.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

 

Image courtesy of: Dennis Hill, 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