Images Magazine November 18

www.images-magazine.com NOVEMBER 2018 images 29 TIPS & TECHNIQUES heat presses, which flatten and degrade the image in the course of drying it. It is uncommon for flash cure units to be used to dry pretreatment since they are equally as slow as heat presses and lack the ability to flatten fibres prior to printing. Infrared conveyor dryers Infrared conveyors dryers are larger and more costly units that require two square metres or more of floor space, and consist of a heating chamber positioned above a conveyor belt. These machines use infrared radiation to rapidly raise the temperature of the ink (not the air in the heating chamber) to evaporate moisture as the garment is conveyed. Some infrared conveyor dryers such as the Vastex LittleRed X2D and X3D models are designed specifically for DTG applications and feature a pre-heating zone that boosts the ink to its ideal evaporation temperature of approximately 160°C in the first several centimetres of conveyor travel, maximising the amount of conveyor travel during which evaporation occurs at the greatest rate. This allows the highest possible conveyor belt speeds, maximising the rate at which garments can be dried before exiting the heating chamber. The efficiency afforded by DTG- specific infrared conveyor dryers can benefit the pretreatment phase of the DTG process by drying pretreated garments many times faster than is possible when using a heat press or flash cure unit. This also relegates the heat press to flattening of raised fibres prior to printing, accomplished in a one-second ‘touch’ per garment. Drying of the DTG-printed image also benefits from the speed and efficiency of a DTG-specific conveyor dryer, which preserves the quality of the printed image while eliminating a capacity bottleneck common in DTG applications. Another benefit of the conveyor dryer is that it allows the curing to be unattended. Once it is set up properly, the garments are simply placed on the belt, and the rest is automatic. Applications and choice For most DTG printing businesses, the production process involves several steps: spraying pretreatment, drying pretreatment, flattening fibres, inkjet printing of the garment and drying of the printed garment. The selection of a heat press, flash cure unit or conveyor dryer, alone or in combination, should hinge on your print shop’s anticipated volume, your budget and the desired print quality. www.vastex.com A heat press can dry pretreatment, flatten raised fibres and dry the DTG printed image, at low cost, but at low rates and with reduced quality