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

Super Air Wipe Vs. Block Type Air Wipe

When you need to cool, blow off or dry extruded objects there are several options available, however only the EXAIR Super Air Wipe delivers the performance, efficiency and versatility that most applications require!  In today’s blog we will contrast some of the differences between the EXAIR Super Air Wipe and block type air wipes.

The split-ring design of EXAIR’s Super Air Wipe offers easy clamping around the surface of the material moving through it and eliminates the need for time-consuming, cumbersome threading.  While Block Type Air Wipes are also of split design the diameter of the material drawn through it can typically only vary by approximately 1/16″!  In contrast the EXAIR Super Air Wipe is effective on materials that can range in size from approximately half the throat diameter up to within a fraction of an inch on the internal diameter.  This range can be as large as five to six inches in our largest Super Air Wipes.  The key is to ensure the material does not contact the Super Air Wipe.

Mounting the EXAIR Super Air Wipe is a snap, it can be accomplished by using either the 1/4 – 20 tapped holes on the downstream side or by utilizing a hard pipe compressed air supply line.  The access to these bolt holes makes it easy to change out in the event the production line runs several different sizes. If needed the included stainless steel 1/4-20 bolts can also be removed and longer bolts could be installed to mount from either side.

Connecting the EXAIR Super Air Wipe to your compressed air supply is straightforward.  For sizes up for 4″ throat diameter a stainless steel braided connecting hose is supplied pre-installed from the factory and a single 1/4″ FNPT inlet is used to supply the entire wipe.  For the 5″ up to 7″ throat diameter there is a single 1/4″ FNPT inlet on each half of the wipe which would need to be connected with compressed air.  Lastly, the 9″ and 11″ sizes from stock each have two 1/4″ FNPT inlet on each half of the wipe which would need to be connected to provide the appropriate flow for optimal performance.

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EXAIR Super Air Wipe features hinged design for trouble-free threading

Another very important consideration is the temperature of the material you are running.  EXAIR Aluminum Super Air Wipes are rated for temperatures up to 400°F (204°C) with the Stainless Steel models rated up to 800°F (427°C).    Typically, block air wipes are made from delrin or polypropylene with a replaceable wear liner,  unfortunately these materials do not tolerate higher temperatures like the EXAIR Super Air Wipes.

Super Air Wipe extrusion save
EXAIR Super Air Wipe cooling an extrusion, high temperatures are not a problem!

To explain how the EXAIR Super Air Wipes work, reference the animation below: Compressed air flows through the inlet (1) of the Air Wipe into the annular chamber (2).  It is then throttled through a small ring nozzle (3) at high velocity.  This primary air stream adheres to the Coanda profile (4), which directs down the angled surface of the Air Wipe.  A low pressure is created at the center (5) inducing a high volume flow of surrounding air into the primary airstream.  As the airflow exits the slot, it creates a conical 360° ring of air that will attach to the surface of the material running through it (6) uniformly wiping the entire surface with the high velocity airflow.

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How The Super Air Wipe Works

While block style air wipes have a  fixed performance because they operate off a series of non-adjustable drilled holes, the EXAIR Super Air Wipe operates off an adjustable shim design.  As shown in the figure above the shim sets the gap opening of the ring nozzle (3).  The stock thickness of the stainless steel shim is .002″ (.05mm), shims can be stacked to provide a coarse adjustment in volumetric air flow.  Custom shim thicknesses are also available to tailor the performance to your needs.   The shim thickness coupled with a pressure regulator gives the Super Air Wipes adjustability from a gentle breeze to remove light debris or provide cooling all the way up to a forceful blast to remove more viscous fluids or provide quick cooling.

The EXAIR Super Air Wipe is 1.13″ (29mm) thick on all (11) Aluminum models that range in size from 3/8″ (10mm) to 11″ (279mm) throat diameter and all (5) Stainless Steel models that range in size from 1/2″ (50mm) to 4″ (102mm).

Super Air Wipe Family Photo

The Aluminum Super Air Wipe is available in 11 sizes 3/8″, 1/2″, 1″, 2″, 3″, 4″, 5″, 6″, 7″, 9″ & 11″; the Stainless Steel Super Air Wipe comes in 5 sizes, 1/2″, 1″, 2″, 3″ & 4″…all from stock!

So when you need to cool, blow off or dry extruded material or need expert advice on safe, quiet and efficient point of use compressed air products, give us a call.  We would enjoy hearing from you!

Steve Harrison
Application Engineer
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Super Air Wipe Cools, Cleans and Dries Extruded Shapes

We have many customers that use the manufacturing process of extrusion to make their various type of products.  EXAIR has an Intelligent Compressed Air Product that works very well with these processes to provide a drying, blowoff and cooling function.

Many types of products are produced via the process of extrusion, which is to shape (as metal or plastic) by forcing through a die.  There are many advantages to the extrusion process, including it being a continuous operation, it runs at high speeds, is good for high volume and low production costs, as well as many other factors.

The extrusion process typically requires heating of the metal billet or melting of the plastic to a high enough temperature to allow it to flow and be shaped as it it forced through the die. After the product has passed through the die and has been shaped it must be cooled and this is usually achieved by passing the it through a water bath.  Once the material has been cooled, it needs to be dried to remove the moisture, before the extrusion enters the next stage of processing, like getting cut to length or printed upon.

The EXAIR Super Air Wipe is ideal for blowoff, drying, cleaning and cooling of continuous materials such as extrusions, pipe, cable and more.

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The Super Air Wipe has a split design which offers easy clamping around the surface of the material, eliminating the need for threading. All Super Air Wipe models include stainless steel screws and shims.  Stainless Steel wire braided hose which is plumbed to each half, is included on sizes up to 4″ to simplify installation and plumbing. Aluminum models are rated to 400°F and the stainless steel models for temperatures up to 800°F.  Models are available in size from 1/2″ to 11″ Throat Diameters.

The Super Air Wipe provides a uniform, 360° air stream that is ideal for drying and cooling of extruded materials.

To discuss your application and how an EXAIR Super Air Wipe can benefit you extrusion process, feel free to contact EXAIR and myself or one of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

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