ABSTRACT
Recent progress had been made in silicone-coated products that are curable by electron beam (EB) and ultraviolet (UV). Advantages of UV and EB converting processes are shown in Table 22.1. Of these new products, in which the release levels range between 25 and 50 g per 25 mm wide strip, typical viscosities of the materials tested are in the range of 500 to 1000 cp at room temperature. These silicone products are manufactured by Th. Goldschmidt, in West Germany, and Lord Corporation, in Pennsylvania, and other companies. The UV products are either one-part premixed/ready-to-use materials, or two-component products that require nitrogen inerting to overcome surface smear and to achieve a complete cure at web speeds up to 30 m/min per each UV lamp. A schematic diagram of the nitrogen inerting process is shown in Figure 22.1. The UV lamps used for curing are rated at 300 W/in. (120 W/cm per lamp). The EB products are also premixed/ready-to-use, and as with the UV chemistries, they also require nitrogen inerting to obtain a full cure at typical web speeds of 200 m/min. The energy dosage is approximately 2 megarads (Mrad). A schematic diagram of an EB processor is shown in Figure 22.2.
