An E-Vac Improves Manufacturing of Contact Lenses

 

Contact Lens

Vacuum pumps have vanes, electric motors, and bearings that can wear out.

A contact lens manufacturer called EXAIR to ask about our E-Vac Vacuum Generators.  Their operation consisted of using a small vacuum cup to grab the contact lens for polishing.  Due to the long hours of operation, their mechanical vacuum pump would start to malfunction.  The vacuum pressure would start to decline, and the contact lens would begin to shift or fall off.  This would affect the clarity of the lens, and it would have to be rejected.

Our company found that the vanes in the vacuum pumps would start to wear. They would have to shut down the process to recondition the vanes, causing down time.  After a few times of refurbishing the pump heads, the bearings in the electric motors would then start to wear.  A loud high pitch noise would be generated, indicating that the motors needed to be replaced.  This would cause even more downtime.

EXAIR E-Vac Vacuum Generator

After carefully reviewing the customer’s needs, I suggested the model 810002M E-Vac High Vacuum Generator.  This model can create a vacuum level of 27” Hg with only using 2 SCFM of compressed air; perfect for holding the contact lens firm to the vacuum cup for polishing.  The E-Vac has no moving parts or bearing to wear out.  They use compressed air to generate a venturi vacuum, so the only maintenance is to clean or change the compressed air filter yearly.  Its compact size made the E-Vac more versatile than the much larger vacuum pump that it would replace.  The customer could mount the E-Vac much closer reducing the volume of air in the vacuum lines to evacuate.  This gave them an almost instantaneous vacuum at the lens which could improve the speed of the operation.

If you wish to eliminate downtime to fix, change, or recondition motors and pumps, the E-Vac could be the vacuum pump for you.  If you need help to size the correct model for your application, you can contact an Application Engineer at EXAIR.

John Ball
Application Engineer

Email: johnball@exair.com
Twitter: @EXAIR_jb

 

Photo: Contact Lens by Andy Simmons.  Creative Commons Attribution-NoDerivs 2.0 Generic.

Video Blog: The EXAIR Ultrasonic Leak Detector Works for Vacuum Leaks?

 

A brief video showcasing the EXAIR model 9061, Ultrasonic Leak Detector’s, performance on vacuum leaks.  For more information or questions on what else the ULD can be used for, contact an Application Engineer!

 

Brian Farno
Application Engineer Manager
BrianFarno@EXAIR.com
@EXAIR_BF

Even Our Customers Are Sending “Holiday Gifts”

Lately, it certainly has felt like Christmas here at the factory.  Two customers sent in some sample parts  for us to test and provide solutions for their application issues.  Opening the box is like unwrapping a present, what surprise will we find inside?

The first customer currently uses the Line Vac to convey (3) different parts from the floor to a hopper for the assembly process.  (2) of the (3) parts transfer very well, but the third conveys a little too slowly. Having all three parts here at EXAIR allows us to set up testing and determine what the root cause is and recommend a solution that will work equally well for all three parts.

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The second is interested in our vacuum technologies to pick and place some fiber board material products.  Due to the curved surfaces and porous material, getting a good vacuum could be a challenge. By having the sample parts here, we can utilize our Demo Room, and try various E-Vacs with various vacuum cup designs and possibly the Line Vac or Air Amplifiers  to develop a good suction on each item.

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When it isn’t possible to send in samples, we will stand behind the EXAIR Unconditional Guarantee – purchase a stocked catalog item, and you have 30 days to try it your facility, in your process, under your real world conditions.  If after the 30 days you aren’t satisfied, send it back for a full refund – and try something else!

To discuss your application and find out information about sending in material samples to confirm that an EXAIR Intelligent Compressed Air Product can help your process, feel free to contact EXAIR and one of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

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Adjustability=Flexibility=Wide Ranging Performance

Recently, I moved into a new house, and it didn’t have bathroom vent fans.  In order to prevent mold and mildew growth from the humid shower air; we decided to install them ourselves.  Going to the local home goods store, we were faced with a wall of options, with factors such as noise level, CFM rating and of course price.  Going over the myriad of possibilities was headache inducing and of course, the bathroom size was borderline between a small and mid-size unit. The decision came down to – pay more and oversize it or risk installing an undersized unit.  If only they made a unit to cover a wide variety of conditions.

Here at EXAIR, we make many types of Intelligent Compressed Air Products.  Many times, when we are talking to customers, the right size or performance needed isn’t quite clear.  Fortunately, many of the products we make are flexible, and allow for adjustability and increased range of performance to best match the specific need of the application.

For example, The Super Air Knives and Super Air Wipes have available Shim Sets to increase or decrease the air gap and change the force and flow.  The shims are easily installed, and come in a wide choice of sizes. Super Air Knives are available, from stock, in aluminum, 303SS, 316SS, and PVDF. Super Air Wipes are made from aluminum or 303 SS.

The Super Air Amplifiers also have available patented Shim Sets to fix the air flow at a predetermined setting. Adjustable Air Amplifiers have an infinitely adjustable air gap which can easily be set to match the application needs if a predetermined flow is not preferred. Adjustable Air Amplifiers also have a smaller footprint than Super Air Amplifiers and can also use the aforementioned shims to preset the air flow in applications where space is limited. These are available in 303 stainless steel and aluminum. We also have a high temperature option.

adjustable Air Amplifier

Adjustable Air Amplifier

Within our already enormous and flexible Air Nozzles & Jets product line, the Flat Super Air Nozzles have available Shim Sets to provide the ability to adjust the force and flow for blowoff or cleaning operation.  The model 1009 Adjustable Air Nozzle has an adjustable gap setting, allowing you to “tune in” the force and flow to meet the application requirement.  Also, the Adjustable Air Jet provides an adjustable gap setting to control the air flow performance. Flexibility also comes from the available materials of zinc/aluminum, aluminum, 303SS, 316SS and PEEK thermoplastic.

For vacuum generation, the Adjustable E-Vac allows for the vacuum and flow rate to be easily adjusted.  With a simple turn of the unit, the vacuum and flow levels can be changed to overcome porosity and increase or decrease the lifting power.

Adjustable EVac

Adjustable E-Vac

There are several other Intelligent Compressed Air Products that EXAIR manufactures that offer the adjustability and flexibility, such as Vortex Tubes and Adjustable Spot Coolers.

If only EXAIR manufactured bathroom fans, I could have ensured making the right choice and be able to match the performance to exactly meet my application needs.

Brian Bergmann
Application Engineer
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Vacuum Generators: Adjustable E-Vac Holds Parts To Work Station

I’ve written before about the diversity of applications that EXAIR’s compressed air products can be used for – the Super Air Knife and the Line Vac come to mind – but of all the products in our catalog, none have a longer list of applications than the E-Vac Vacuum Generators:

While they're probably most popular for "pick and place" (as evidenced by our catalog photos) the EXAIR E-Vac's boast a wide variety of uses.

While they’re probably most popular for “pick and place” (as evidenced by our catalog photos) the EXAIR E-Vac’s boast a wide variety of uses.

I had the pleasure of helping a customer specify a product another popular application recently: clamping and chucking.  This caller had a machining center with a vacuum table – if you’re unfamiliar, it looks like an air hockey table, and works like one too, only in reverse: instead of using blowing air through all those little holes out to “float” the puck on the surface, it pulls air in through them to pull the part down and hold it in place.

This was for a relatively small table surface…about 9″ x 14″…and some of the holes could be blocked, if smaller parts were to be held down.  It was originally equipped with an electrically driven vacuum pump, but it had seen better days, and a replacement was going to be a little pricey.  They already had compressed air running to the machine, and were keenly interested in something small, inexpensive, and with no moving parts – like the Adjustable E-Vac.

After some discussion of the specs on their vacuum pump, we provided a Model 840008M Adjustable E-Vac & Muffler.  This not only gives them the ability to easily change the vacuum level & flow for different sized parts, but it also has a larger throat than the In-Line E-Vacs, meaning it won’t get clogged by the finite amount of dust & small particulate that can make it through the vacuum table’s holes.

EXAIR has four sizes of Adjustable E-Vac Vacuum Generators in stock.

EXAIR has four sizes of Adjustable E-Vac Vacuum Generators in stock.

By my count, we’ve still got fourteen E-Vac applications that I haven’t discussed in a blog yet.  If you’ve got one that you’d like to talk about (and give me something to write about,) feel free to call me anytime.

Russ Bowman
Application Engineer
EXAIR Corporation
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E-vac and Vacuum Cups for Lifting Saw Cut Aluminum Bar Stock

E-vac brick

E-vac and vacuum cups lift, large, heavy objects!

Our Chinese distributor had a customer who was producing the aluminum pieces that are formed into wheels for the automotive industry. Their process involved saw cutting large diameter, aluminum bar stock so it could be further processed.

The problem was once the parts were saw cut, they were slippery and difficult to handle. So, the customer was looking for a good way to handle these parts that was safe and effective for the operator as well. Our distributor offered the idea of using vacuum cups and an EXAIR E-vac for the project.

We determined that the aluminum raw stock that would be picked up would have an effective diameter of 254 mm on which vacuum cups could pick up the part for transfer. Also, the parts could weigh up to 45 kilos. So, we needed to find a vacuum cup (or cups) that could pick up that much weight with the surface area allotted to us. After reviewing our options, we came to the conclusions that (3) model 900759 vacuum cups would have a combined lifting capacity of 100 kilos when powered at -71 kPa vacuum. These vacuum cups have a 108 mm diameter and so can fit nicely in a triangular orientation on the saw cut area of the aluminum part.

Then came the part where we recommend which E-vac generator to use. We already calculated in our usual 2X safety factor for weight being lifted. So we are quite confident that the cups can do their job as long as sufficient vacuum could be maintained. We are lifting solid aluminum, so we know the material is non-porous. So, that’s the version of the E-vacs we will take into consideration for the project.

The part about determining which E-vac to recommend is not as clear cut and well defined as picking the vacuum cups is. So we must use our best judgement based on the weight of the item, the size and number of vacuum cups being used, and the surface finish of the material. Since the material will be somewhat on the heavy side and it would be a real problem if it were dropped, I recommended our distributor go with one E-vac vacuum generator per each vacuum cup. The vacuum generator I recommended was from the middle of the available models from a performance standpoint. That was model 810008M (8.4 SCFM Non-porous E-vac with straight through muffler). In this way, if one cup were to lose vacuum for whatever unforeseen reason, the other two could still support the full weight of the object as it is being lifted and moved.

Once the customer had their lifting fixture fabricated and the E-vacs with vacuum cups mounted, the lifting unit worked very well to address the customer’s concerns about worker productivity and safety.

E-vacs can be used for a variety of tasks, but lifting and placing applications tend to be the more prevalent ones. If you have a lifting or moving application of your own and think that vacuum technology might be useful, contact us with your questions. We thrive on helping folks like you solve such problems in industry.

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

Vacuum Evacuation Time for E-Vacs

A tank manufacturer was building specially designed tanks for their customer. These tanks were to hold cryogenic materials, so they had to create an outer shell to hold a special type of insulation material.  This shell maintained a 1/2 inch (13 mm) gap around the tank.  The overall dimensions of the cylindrical tanks were 10 feet (3 meters) in diameter and 43 feet (13 meters) in length.  The internal volume of the gapped area was 56.1 cubic feet (1560 liters).  With this type of insulation, it had to be under a negative pressure, or vacuum, to help facilitate the insulation properties.  So, when the tanks were completed, they had to check for leaks between the shell and the tank.  The requirement was to draw a vacuum to 21” Hg  and to hold it at that level for 30 minutes.  As the tank manufacturer researched vacuum pumps to test their design, they came across EXAIR.

Being that they were not familiar with EXAIR E-Vacs, they wondered how they worked. I explained that the E-Vac uses compressed air to create a vacuum by a venturi method.  It can reach vacuum levels up to 27” Hg in a very compact and lightweight design.  Being that they do not have any moving parts, they are very durable and long lasting in systems with on/off cycling or continuous running.  The tank manufacturer was very intrigued by this concept as they had electric vacuum pumps fail in the past.

He wondered about the evacuation time to get to 21” Hg of vacuum. The idea for the leak test was to reach the vacuum level and turn a valve off to isolate the area.  From there, they would watch a gage to see if they were losing vacuum.  If so, then they would have to find and fix the leak and recheck.  If the vacuum pressure held, then they could fill the area between the shell and the tank with insulation material; use the E-Vac to put it under vacuum; and cap.  Because the volume was large and time was a concern, I suggested the model 840060M.  This had the highest vacuum flow rate and can reach a vacuum level of 25” Hg.

Adjustable E-Vacs

Adjustable E-Vacs

To help explain a little better about vacuums, when you are near atmospheric pressure, you have the highest air flow rates. As the vacuum levels rise, less air is present to be drawn out.  When you reach the vacuum pump capacity or complete vacuum, the flow rate is zero.  You can notice this with your vacuum at home.  As you turn the vacuum on, the air is rushing in (the highest flow rate/very low vacuum pressure).  As you cover it with your hand, the vacuum pressure increases and the flow rate decreases to zero (no flow rate/highest vacuum pressure). To figure the amount of time to reach a certain vacuum level, we have to take into consideration the different flow rates as the vacuum level continues to increase.  The equation that we use is below:

Equation 1:  t = V * ln(p0 / p1)  / q

t = evacuation time (min)

V = enclosed volume (ft^3)

p0 = atmospheric pressure (“Hg)

p1 = end vacuum pressure (“Hg)

q = flow rate of vacuum pump (SCFM)

With the performance data of the model 840060M E-Vac, we can start to calculate the time to reach 21” Hg vacuum. A couple of details are required to make the equation work properly.  Just as a note, the end vacuum pressure, p1, has to be converted to an absolute pressure. This will equate to 29.92” Hg – 21” Hg = 8.92” Hg (absolute).

Here are the details for Equation 1:

V = 56.1 ft^3 (above)

p0 = 29.92” Hg (absolute start)

p1 = 8.92” Hg (absolute target)

q = 70 SCFM (cataloged at 80 psig)

Thus,

t = V * ln(p0 / p1) / q

t = 56.1 ft^3 * ln(29.92” Hg/8.92” Hg) / 70 SCFM

t = 0.97 minutes

For this application, the model 840060M worked great for both procedures. With less than 1 minute to get to the desired set point, it didn’t hinder production for leak checks or to vacuum set the insulation. If you have a timing sequence with vacuum chambers or “pick and place” systems, you can use this equation to find the best E to meet your goal.  If you need any additional help, you can always contact an Application Engineer at EXAIR.

John Ball

Application Engineer

Email: johnball@exair.com

Twitter: @EXAIR_jb

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