Recently we had the opportunity to work with a well-known manufacturer of men’s and women’s clothing, boots, and accessories, famous for their high quality, rugged workwear. The manufacturer was using one of our older Cold Air Guns to cool the double needle in a banding machine that was sewing Cordura fabric. The Cold Air Gun keeps the needles cool, preventing the looper thread from burning in two.
The same manufactured noticed another fabric-related problem where a Cold Air Gun would be a beneficial solution. When fabric to make a belt loop comes off the fusing machine, it needs to be cooled before moving to the next stage of production. To finish the process, the material for the belt loop is folded over narrow adhesive tape and sewn together. The material is then sewn into long 250-300 ft. strips, after which the material enters a heater for approximately 60 seconds. As the material is heated, it fuses to stiffen and strengthen. When the fused belt loop exits the heater, it’s nearly 150°F and has to cool before moving to the next stage of production.
The manufacturer decided to try the Cold Air Gun that was already in use on their banding machine to see how it would work in the belt loop fusing process. When the process worked, the manufacturers’ engineers contacted Vortec to determine which Cold Air Gun model they were already using. By looking at the color of the generator, the Vortec application engineer concluded that the manufacturer had a model 620, 25 scfm Cold Air Gun.
To make the Cold Air Gun fit the application better, Vortec Engineers suggested utilizing the flexible dual nozzle to split the cold air stream to cool the material before and after the wheel that compresses the heated material together.
After purchasing and installing the model 622 Cold Air Gun, the manufacturer was able to cool the belt loop material from 150°F to 85°F, which allowed the fabric to be immediately spooled without damage to the material or wait time between the processes.
If you’re curious about which Cold Air Gun model you have, or what generator is inside your Vortex Tube, watch our video on locating and changing your generators.
The cold air gun operates on the vortex tube principle. High pressure (compressed) air enters the inlet and flows into the annular space surrounding the generator. As it flows through the generator nozzles, the air loses some of its pressure, expands and begins to spin in the generator where it gains near sonic velocity. The nozzles are oriented so that the air is injected tangentially to the circumference of the generation chamber. All the air leaves the generation chamber and goes into the hot tube. Centrifugal force keeps the air near the inside wall of the hot tube as it moves toward the valve at the hot end. At the end of the hot tube is a valve that is adjusted to allow only a portion of the air to escape through a hot air muffler. The remaining air is forced to the center of the hot tube, creating a counter-current flow where, still spinning, circulates back to the cold outlet. The air travels the entire length of the hot tube, through the center of the vortex generation chamber and then through a cold air muffler and to the cold outlet, where chilled air is directed through the flexible Locline nozzle.
Watch this video to learn more about Vortex Tube Technology: https://www.vortec.com/vortex-tubes-video
Find more Cold Air Gun product information here: https://www.vortec.com/cold-air-guns