When a customer has a problem with a labeling process within their operation, many times they call EXAIR to provide a solution. The company in this example manufactures honey and dispenses it into jars and squeeze bottles. Due to an increase in demand, they were looking to increase their output. To do this, they simply increased the speed of their conveyor to accommodate approximately 70 jars per minute instead of their typical 50 jars per minute. This began to present a problem and they reached out to EXAIR for a solution.
After dispensing the honey, the jars and bottles travel through a washing station. The containers pass through a heated chamber that dries the excess water from the jar. At the higher speed, they were experiencing some residual water left on the containers. This began to pose an issue when they reached the labeling process. With water remaining on the jars, the labels adhesive would not adhere properly. This led to an increased amount of rejections and additional rework time to remove the rest of the label and re-run the defective containers.
They had a point in the conveyor just prior to labeling that the sides of the jar would be exposed. My recommendation was to install (2) 110009 9” Super Air Knives on each side of the conveyor to remove the water that was left after exiting the drying chamber. This worked like a charm and the customer was able to maintain an increased level of output without experiencing any further complications. Their previous rate of production without the Super Air Knives was approximately 50 jars per minute. By installing the Super Air Knives, they were able fully realize their 70 jars per minute goal and increase their production by 40%!
The laminar flow that exits the Super Air Knife wraps itself around the outside of the jar, stripping away any leftover moisture. Supplied at 80 PSIG, each knife will consume only 26.1 SCFM of compressed air at a sound level of just 69 dBA. The flow and force from the knife are infinitely adjustable by dialing in the operating pressure with a pressure regulator or swapping out the shims with a Super Air Knife Shim Set. If you’re experiencing an issue with residual water or liquid on your product that is causing a problem during production, give us a call. An Application Engineer will be happy to take a look and recommend the most suitable blowoff solution!
A glove manufacturer needed to decrease the reject rate with their natural rubber gloves. They were seeing brush marks in the rubber material which was a visual defect. Their operation used a ceramic hand that was used to form the size of the glove. After the rubber material was applied, it was dipped into water to set the material. It would come out of the water tank, and a mechanism on the conveyor would rotate the hands to “shake” off the excess water. It would then go over brushes to wipe the water from in between the fingers. Much of the water had to be removed before it entered into the coagulation tank because it would affect the stretching ability of the glove. With their current operation, they were seeing the scuff marks from the brushes which was a visual defect. This cost them down time and product rejects. So, they contacted EXAIR to see if we could help.
In looking at their process, they had two conveyors running side by side with each other. This made it a bit more difficult as we could only work on one side. Being that the ceramic hand rotated around twice in 36” before hitting the brushes, I could focus in this area. When it comes to wiping products without touching it, air is required. And EXAIR knows how to use compressed air very efficiently, safely, and effectively. For this application, I suggested our model 110236 Super Air Knife kit. It has an overall length of 36” which could span the target area. It comes with a filter, regulator, and shim set to clean and control the air flow. It would be able to “wipe” the water off the hands like a non-contact squeegee. The air flow from the Super Air Knife will hug the exterior portion of the hand; removing the water from the surface and in between the fingers. They removed the brushes and did not have to worry about brush marks on the glove.
If you require a non-contact wiping in your application, use EXAIR Intelligent Compressed Products to accomplish this. You will not have to keep replacing items that wear or use items that cause damage to your product. EXAIR has the ability to use compressed air to create a strong force without scraping or scratching your material.
A plastic company was developing thin layered films in their laboratory on a miniature prototype machine. It was designed for trial runs to make 24” wide material from various plastics, blends, and thicknesses. They would place the plastic pellets into a hopper, and the material would be melted and extruded into a flat sheet. To harden the material, it would land onto a cold drum, a large cylinder that had chilled water running through it. To keep the sheet on the surface of the cold drum, they had a blower air knife. In addition to the blower air knife, they had to use two ¼” copper air lines blowing on the outside section of the film. Whenever they decided to make a change to their process, change material runs, or even for clean up; they had to move the blower air knife from the cold drum. This was a hassle as it had a 3” hose attached to a blower. It was very cumbersome and awkward to handle. They heard about the EXAIR Super Air Knives, and they wanted me to do a comparison to their current system. I was glad to compare the EXAIR 110224 Super Air Knife to their blower-type air knife system.
They were getting “stretch” marks on the plastic film.
Blower-type air knife – Hot air is generated by the blower system. When the hot air hits the cool surface, it will cause an uneven hardening of the material, causing stretch marks.
Super Air Knife – It has a 40:1 amplification ratio. That means that 40 parts of the ambient air is entrained with 1 part of compressed air. Being that the ambient air is much cooler than the hot air from the blower system, it actually aides in cooling. There is no thermal shock to the material, and hardening is better and faster.
They required an even force across the surface of the plastic film to keep against the cold drum.
Blower-type air knife – Their design had one 4” line feeding into the side of the blower air knife. This would cause 2 issues for an even force. As the velocity of the air hits the opposite side of the knife, the closed end, a turbulent air flow is developed. Also, there would be a slight negative pressures at the entrance caused by the velocity of the air entering. This turbulent mayhem and slight negative pressure are very inconsistent in force and velocity. The reason that they had to add the additional two ¼” copper lines to blow compressed air on the outside edges.
Super Air Knife – The flow that is delivered from the Super Air Knife is laminar. This means that the force and velocity is consistent across the entire length, even on the outside. With this even force, the film is held evenly and securely onto the cold drum.
They needed maneuverability for change overs and clean up.
Blower-type air knife – To keep the needed pressure on the film, they had to have the blower air knife ¼” from the surface of the cold drum. So, before a change over or clean up procedure is started, they had to remove the knife and attachments. This was time consuming, cumbersome, and a headache to move.
Super Air Knife – With the compact design, the Super Air Knife has a large force in a small package. It has a footprint of 1 ¾” X 1 ½” X 24” long with only two ¼” NPT compressed air lines feeding it. The force measurement is equivalent from 3” to 12” away from the surface. Now, they could mount the Super Air Knife far enough to not disrupt their cleaning or change-over procedures. This saved them much time in changing to different materials and clean up.
They wondered about the compressed air usage.
Blower-type air knife – This device does not require any compressed air to operate, but because it could not keep the film against the cold drum on the outer edges, they did have to use compressed air. With the two ¼” copper tubing at 80 psig, they were using a total of 79 SCFM of compressed air.
Super Air Knife – As a direct comparison to their air usage, the Super Air Knife would use 70 SCFM of compressed air at 80 psig across the entire width of the film. But with the unique design to entrain 40 parts of ambient air, it gives the Super Air Knife a powerful force. They were able to reduce the air pressure to 40 PSIG to keep the film on the cold roll, which also cut the air consumption to 41 SCFM. This efficient design helped them to save on compressed air without the added cost of the electricity to run the blower motor.
Any other comparisons between the two products
Blower-type air knife – With the sound of the blower and the turbulent air flow, the unit was very loud. It had a sound level over 90 dBA, and with the operators working around this system, they required PPE for hearing.
Super Air Knife – These units are very quiet. At 40 PSIG, the sound level is only 61 dBA. (Just as a reference, the sound level is 72 dBA at 100 PSIG). This was very nice for the operators as they did not need to wear the ear plugs to work around their machine all day.
When it comes to using the EXAIR Super Air Knife, it has many benefits over the blower-type air knife. We can even include the initial cost in which we would be about 1/10 the cost of a blower-type air knife system. For this customer above, they were delighted to replace that system with the Super Air Knife, and start running plastic film effectively, efficiently, and quietly on their miniature prototype machine.
I had a customer contact me about the performance of his EXAIR Super Air Knives. They were painting panels using an electrophoretic process. This process uses an electrical voltage to put a charge on the steel panel for coating. As the parts get dipped, the oppositely charged coating is attracted to the surface. The parts then get rinsed before going into an oven to cross link and set the paint. They purchased two 48 inch (122 cm) long Super Air Knife Kits, model 110248, and he mounted one on each side of the steel panels to blow water off after the rinse cycle. The 46 inch (117 cm) long panels were attached to a rack hanging on an overhead conveying system. As the panels left the rinsing system, the Super Air Knives would blow the water off both sides. The customer saw some visual defects caused by water droplets and had concerns about the effectiveness of the Super Air Knife.
In these cases, we have to do some forensics to solve the problem. Usually poor performance is caused by undersized fittings, tubing, quick disconnects, improperly sized pneumatic accessories, and/or too small of an air compressor. As we went through the checklist, he did have the correct sized pipe, fittings, and compressed air requirements to operate the Super Air Knife properly.
I then went back to the basics in the setup of the Super Air Knife. I found out that he positioned the Super Air Knife to be perpendicular to the panels. With the air flow hitting the surface at a 90 degree angle, it was allowing the water to be splashed back onto the cleaned areas. I had a few suggestions to help improve the drying process.
Angle – EXAIR machined a chamfer on the cap of the Super Air Knife, and it can be used as a starting position for a mounting angle. The chamfer should be parallel with the target. This will create an air flow angle at about 45 degrees. This angle will increase the contact area and contact time which is very beneficial for removing water, debris and/or heat. See the below picture in showing the chamfer.
Distance – For optimum performance, the Air Knife should be between 3 inches and 12 inches (76mm to 305mm) from the target. If you are too close, the amplification ratio is sacrificed, and the force is reduced. If you are too far, the air pattern will start to morph, and the velocity and force will begin to decrease. It can still work, but the efficiency is reduced.
Counter-Flow – The air flow should be blowing against the target, in a counter-flow direction. Example; if the parts are moving from left to right, you would want the Super Air Knife to blow from right to left. This will allow the contamination to be blown back away from the cleaned surfaces, and it will increase the impact force to remove contamination i.e. a head-on collision vs. a rear-end collision.
Many customers like to start with their Super Air Knives aiming directly at the target, as described in the above application. This can decrease the efficiency for blowing off contamination or removing heat. The diagram below shows how the angle can really help to improve the performance.
With these few simple steps in your installation, you can begin optimizing the performance of the EXAIR Super Air Knives. You can position the air knives to better suit your application. but with a good starting point, it can make it easier to maximize the product effectiveness.