Profiling a Dryer With the advent of screen printing on performancewear, tri-blends and 100% polyester garments came the need to precisely control oven temperatures to avoid scorching and dye migration when printing on these heat-sensitive fabrics. Excessive dryer heat - temperatures higher than 300˚F - causes the polyester fabric to " gas out " and release dye from the garment through the sublimation process. This dye-bleeding issue has fueled the need for low-cure inks in our industry. Keeping polyester garments below the 300˚F melting point is the key to reducing dye sublimation. The best way to profile or " map " a dryer is by using a thermal temperature probe to test its accuracy. The thermal probe has a long lead wire with a " donut " attachment that supports the conductive wire that runs to the heat sensor. When using this device, remember the following: 1. The crosshair wires on the donut probe should be embedded in the ink on the garment and cycled through the dryer. 2. The digital display will show the rise in temperature as the donut probe passes through the oven section. 3. Write the temperature - after every 2 feet the probe travels on the dryer belt - on graph paper. The result will be a chart that indicates at which point in the oven the garment reached the necessary cure temperature. If the cure temperature isn't reached, make adjustments by either raising the oven temperature or slowing down the conveyor belt. Textile dryers have become more sophisticated since the days of the old percentage timer-type heat controllers that would cycle the heaters on and off, regardless of whether there were garments in the chamber. Today's dryers can be purchased with many high-tech features, including internal heat sensors that monitor the garment's temperature as it passes through the oven; split belts that allow two different ink types - with different cycle times - to run side by side; audible alarms when the oven temperature drops below the desired setting; and more. Doing advance research and following these tips will point you in the right direction and help you make the right decision when you are ready to buy the most important piece of equipment in your screen-printing shop. James Ortolani has more than 30 years of experience in the decorated-apparel industry, specializing in hands-on, direct screen printing and heat-transfer production. For more information or to comment on this article, email James at jamesort12@yahoo.com. Gas-dryer sales surged in the 1990s, and this still is recognized as the most economical dryer type to use in high-production environments. Use Info*Action #18 at impressionsmag.com/infoaction JAN./FEB. 2022 P.43http://impressionsmag.com/news http://impressionsmag.com/business http://impressionsmag.com/screenprinting http://impressionsmag.com/embroidery http://impressionsmag.com/digitaldecorating http://impressionsmag.com/events http://impressionsmag.com/news http://impressionsmag.com/productguide http://impressionsmag.com/catalogcentral http://ImpressionsDirectory.com http://stahls.com http://impressionsmag.com/infoaction http://bit.ly/stahls-max-diff http://impressionsmag.com/designgalleries http://stahls.com http://ImpressionsExpo.com http://www.impressionsmag.com/infoaction