Discrete coating is a web-coating process that is used to apply discrete coated shapes, i.e.: individual polygon patches, stripes and machine-direction lanes, to the substrate. It is used for products that require a relatively small, coated area and an uncoated border around the shape, rather than continuously coating the substrate. It requires special technology to apply the discrete areas so the precise applied shape is coated and does not contact other patches. Also, to be economically efficient, the coating application must start instantly, cannot take the long startup time encountered with continuous web-coating startup, and is a more efficient process than coating the individual areas.
Since the development of discrete coating technology, many new products have been commercialized using this technology. They include:
- Transdermal patches that are applied to the skin and deliver controlled doses of medicine, such as fentanyl, nicotine, nitroglycerine, estradiol, scopolamine
- Anode and cathode strips for thin-film batteries
- Organic light emitting diodes (OLEDs)
- Exothermic weld protectors
- Radio frequency identification device (RFID) patches