Adjustable Spot Cooler Removes Tackiness from Plastic Tubes

Black PVC Tube

A manufacturing plant contacted EXAIR to help them with a “sticky” situation.  This company extruded PVC tubes that would be used as fuel lines on small engines.  Plasticizers are typically used to add flexibility to plastic materials.  For the PVC material above, a plasticizer was added to make it softer and more elastic.  The issue that they saw was the outer surface of the tubes were tacky from the plasticizer and heat which made it difficult to handle in packaging the tubes.

This company extruded many different diameters, but they wanted to target their most difficult size, the smallest tube.  The dimensions were given as 0.187″ (4.7mm) O.D. by .0934″ (2.4mm) I.D., and the feed rate was close to 4 feet/min (1.2 meter/min).  The problem area that they explained was at the end of the production line where the extruded tubes were cut by a blade cutter into 12” (305mm) lengths.  The tubes would then fall into a collection bin for batch processing.  Since the collection bin was setup at a slight upward angle, they wanted the tubes to gather toward one end of the bin.  Since the tubes were still hot and sticking to each other, the operators had to individually handle each tube which was counterproductive and time-consuming.  After our discussions, I suggested that cold air could harden the PVC tube enough by removing heat and help to “set”  the platicizer.  Since they manufactured different sizes and feed rates, we needed to have adjustability as well in our cold air device.

How the Adjustable Spot Cooler Works

One of our most versatile spot cooling instruments is the EXAIR Adjustable Spot Cooler.  This system uses the Vortex Tube technology to convert compressed air into a cold air stream without any moving parts, refrigerants, or motors.  The Adjustable Spot Cooler is a low-cost, reliable, maintenance-free way to give spot cooling for a myriad of industrial applications.  For this customer, this product gave them the versatility that they were needing.

EXAIR stocks these units with either a single or dual point hose kit, a magnetic base, a filter separator, and two additional generators.  The control valve at the end of the unit adjusts the output temperature down to -30 oF (-34 oC) with a turn of a knob.  The generators are specifically engineered to control the amount of compressed air that is used.  Both types of controls will allow this customer to “dial in” the correct cooling capacity for the operation.  The filter separator included with the system will clean the compressed air to keep the unit and the product free of dirt and debris.  The magnetic base which this customer really liked makes the Adjustable Spot Cooler portable for use in different areas.

3925 Adjustable Spot Cooler

I recommended the model 3925 Adjustable Spot Cooler because it had the dual point hose kit to blow cold air on both sides of the tubes.  Since this company had different tube diameters and thicknesses, adjustability was very critical.  If the tubes got too cold, cracks could occur from the blade cutting machine; and, if the tubes were too warm, the tackiness on the surface of the tube would remain.   Once they installed the Adjustable Spot Cooler, this company was able to increase their packaging line for the different size PVC tubes.  Now the operators could reach into the collection bin and grab many aligned tubes instead of individually separating and sorting.

If you have a “sticky” situation, the EXAIR Adjustable Spot Cooler may be a product for you.  The company above was able to have their tubes slide together in the collection bin.  Many applications could be improved by adding cold air.  And, if you have a similar situation, an Application Engineer at EXAIR will be happy to discuss a solution.

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

 

Photo: Black tube by NIMR LondonCC License 2.0

Cold Gun Aircoolant System™: Overview

EXAIR Cold Gun Promotion

Many machining companies like to use coolant to flood their parts for drilling and milling operations.  But what if there was an alternative way?  EXAIR has an interesting technique by using cold air instead of coolant.  This would help save time by eliminating cleaning and drying of parts as well as reducing coolant waste.  EXAIR calls this product our Cold Gun Aircoolant System™.

How the Cold Gun Works

The Cold Gun Aircoolant System uses a Vortex Tube to produce a cold air stream at 50oF (28oC) below supply air temperature.  Heat is one of the major causes for dulling and premature failures for tools, and by blowing cold air, it will reduce the heat buildup in tools while also removing the chips from the surface.  The EXAIR Cold Guns are very compact, portable, and easy to use.  Just attach compressed air to the unit, and it will produce cold air.  Since they do not have any moving parts, Freon, or electricity to operate, it is maintenance-free and long-lasting.  And, EXAIR offers a 5 year “Built To Last” warranty against defects in workmanship and materials.  These systems will extend tool life, improve tolerance control, and increase production rates by replacing coolant during milling, cutting, and drilling operations.

The benefits of using the Cold Gun Aircoolant System extends beyond reducing tool wear, finishing with dry parts, and surface smearing.  It can be used in applications where liquid coolant cannot be used.  This would include wood products, MDF, and plastics.  As insulators, cutting tools will get extremely hot as the material will not remove any heat like with metal chips.  Thus, machining can soften, gall, or burn the surface of the material; allowing only slow speeds for operations.  The cold air from the Cold Gun can keep the tools sharp and the materials hard and firm.  With plastic materials, this is very beneficial as it will keep the plastic rigid for tight tolerance machining.  If burnishing or scoring is occurring, the Cold Gun Aircoolant Systems can help to improve the surface finish of your product.  Other applications would include surface grinders, laser cutters, hot melt setting, and band saws.  The Cold Gun Aircoolant Systems are a low-cost solution that can do a lot of great things to improve processes.

Cold Gun Aircoolant Systems

EXAIR offers two types, the Cold Gun and the High Power Cold Gun.  The High Power Cold Gun blows twice the amount of cold air as the Cold Gun which doubles the cooling capacity.  They come standard with either a Single Point or a Dual Point Hose Kit with a cone and flat nozzle.  All systems come with a magnetic base and a filter separator.  The magnetic base makes this device simple to attach to your machine and start using.  The four models that EXAIR stocks are in the photo above.

EXAIR is running a promotional offer on the Cold Gun Aircoolant Systems.  From now until the end of yr2019; if you buy a Single Point Cold Gun System or a Single Point High Power Cold Gun System; model W5215 and model W5230 respectively, we will include a free model 5902 Dual Point Hose Kit, a $39.00 value, with your system.  And as always, EXAIR offers a 30-day unconditional guarantee for our customers in the U.S. and Canada to try them out.  If you have an application that you believe would be better served with an EXAIR Cold Gun Aircoolant System™, contact an Application Engineer.  And take advantage of our promotional offering by receiving a FREE Dual Point Hose Kit.

 

John Ball
Application Engineer

Email: johnball@exair.com
Twitter: @EXAIR_jb

Promos, Freebies, and Some Amazing Products

Like many companies, here at EXAIR we generally always have a promotional offering.  These rotate throughout the months and this month is no different.  The current offering involves the EXAIR Cold Gun Aircoolant Systems.

These systems help to reduce cutting fluid use, increase production speeds, increase tool life, and has helped more customers than I know.  One customer in particular is a maintenance worker from a welded tube manufacturer.  This facility had very little amount of downtime permitted due to the high efficiency and high volume of orders.  When a machine went down the maintenance team were in like a trauma team to determine the cause of failure and get it remedied to get the line back up and running. One of the biggest problems they would have is when they would have to dry machine a quick part to get the machine back up and running, this would either ruin tools or they would have to slow down the machining time to get the surface finish and dimensions they truly needed.  After talking with us the team ordered a Single Point Cold Gun Aircoolant System as these parts were generally smaller shafts or machine dogs.

They received the system in and sure enough a machine went down.  The crew went to work and once the part needed was found they got to work on their lathe trying to make a new piece.  The Cold Gun held itself straight to the headstock thanks to the integrated magnet and the flexible single point hose kit routed the cold air straight to the cutting point.  They didn’t have to fill up the liquid tank or setup the mist system on the lathe, they simply turned on the compressed air and let the lathe do the work.  They were able to take what had recently been around a three hour machine job with heavy wear on tooling to a two hour job, no finish pass was needed on the part, and their tools weren’t completely spent by the end of the job.

They got the part back into the machine, made adjustments, and then went to work getting the machine back into production.

Right now, if you would like to try out a Cold Gun Aircoolant System you can order before 12/31/2019 and use the link to order through our promotion in order to receive a free Dual Point Hose Kit with your qualified purchase.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

Vortex Tube Cold Fractions Explained

Simply put, a Vortex Tube’s Cold Fraction is the percentage of its supply air that gets directed to the cold end. The rest of the supply air goes out the hot end. Here’s how it works:

The Control Valve is operated by a flat head screwdriver.

No matter what the Cold Fraction is set to, the air coming out the cold end will be lower in temperature, and the air exiting the hot end will be higher in temperature, than the compressed air supply.  The Cold Fraction is set by the position of the Control Valve.    Opening the Control Valve (turning counterclockwise, see blue arrow on photo to right) lowers the Cold Fraction, resulting in lower flow – and a large temperature drop – in the cold air discharge.  Closing the Control Valve (turning clockwise, see red arrow) increases the cold air flow, but results in a smaller temperature drop.  This adjustability is key to the Vortex Tube’s versatility.  Some applications call for higher flows; others call for very low temperatures…more on that in a minute, though.

The Cold Fraction can be set as low as 20% – meaning a small amount (20% to be exact) of the supply air is directed to the cold end, with a large temperature drop.  Conversely, you can set it as high as 80% – meaning most of the supply air goes to the cold end, but the temperature drop isn’t as high.  Our 3400 Series Vortex Tubes are for 20-50% Cold Fractions, and the 3200 Series are for 50-80% Cold Fractions.  Both extremes, and all points in between, are used, depending on the nature of the applications.  Here are some examples:

EXAIR 3400 Series Vortex Tubes, for air as low as -50°F.

A candy maker needed to cool chocolate that had been poured into small molds to make bite-sized, fun-shaped, confections.  Keeping the air flow low was critical…they wanted a nice, smooth surface, not rippled by a blast of air.  A pair of Model 3408 Small Vortex Tubes set to a 40% Cold Fraction produce a 3.2 SCFM cold flow (feels a lot like when you blow on a spoonful of hot soup to cool it down) that’s 110°F colder than the compressed air supply…or about -30°F.  It doesn’t disturb the surface, but cools & sets it in a hurry.  They could turn the Cold Fraction down all the way to 20%, for a cold flow of only 1.6 SCFM (just a whisper, really,) but with a 123°F temperature drop.

Welding and brazing are examples of applications where higher flows are advantageous.  The lower temperature drop doesn’t make all that much difference…turns out, when you’re blowing air onto metal that’s been recently melted, it doesn’t seem to matter much if the air is 20°F or -20°F, as long as there’s a LOT of it.  Our Medium Vortex Tubes are especially popular for this.  An ultrasonic weld that seals the end of a toothpaste tube, for example, is done with a Model 3215 set to an 80% Cold Fraction (12 SCFM of cold flow with a 54°F drop,) while brazing copper pipe fittings needs the higher flow of a Model 3230: the same 80% cold fraction makes 24 SCFM cold flow, with the same 54°F temperature drop.

Regardless of which model you choose, the temperature drop of the cold air flow is determined by only two factors: Cold Fraction setting, and compressed air supply pressure.  If you were wondering where I got all the figures above, they’re all from the Specification & Performance charts published in our catalog:

3200 Series are for max cooling (50-80% Cold Fractions;) 3400’s are for max cold temperature (20-50% Cold Fractions.)
Chocolate cooling in brown; welding/brazing in blue.

EXAIR Vortex Tubes & Spot Cooling Products are a quick & easy way to supply a reliable, controllable flow of cold air, on demand.  If you’d like to find out more, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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