Whenever infrared is used to heat, predry, dry or cure continuously traveling web material — or a continuous stream of flat materials supported on a conveyor — there is a risk of a natural phenomenon referred to as the edge-cooling effect. If the material exceeds 24” in the cross-machine direction (CMD) dimension, edge cooling will occur.
An infrared heater is a box or enclosure of some type that contains one or more infrared emitters. Infrared output from a single infrared emitter typically is uniform throughout its length. However, the closer you are to the edge of the emitter, the closer you are to outside influences that affect the product. Whether the product is 24” wide or more than 200” wide, the outer portion or edges of the material will be subject to these outside influences. Typically, the primary outside influence is the ambient production environment.