An ultraviolet (UV) epoxy may be an adhesive or a coating, depending upon the formula and application, that uses UV light to cure or harden it. UV epoxies have many industrial applications in electronic, medical, automotive, and other fields. Some people use UV epoxies for hobby applications, such as glassware, metal, and plastic work. Hobbyists usually use spot lamps as a UV light source, but there are other types of equipment used in industrial treatments, including lamps integrated into conveyor systems.
A few reasons to choose UV epoxy include cost effectiveness, hardening speed, and controlled cures. Traditional epoxies generally need heat or a long curing time to set. Typically, UV epoxies cure without the need for ovens or drying racks, eliminating costly work in the process. The speed at which UV epoxy cures also reduces manufacturing costs. The ability to control the cure with UV light means that a manufacturer has control over which areas cure quickly.
There are three ways to cure UV epoxy. One method is to use only UV light. The other two methods use UV light with special epoxies that use either moisture or heat to cure. Since UV epoxies cure only when exposed to light, areas in shadow or shielded in other ways do not cure as quickly. Generally, these areas will cure in time, but companies use moisture or heat to speed the curing time. Some manufacturers take advantage of this and use focused beam UV lights to rapidly cure only specific areas.
The light systems used to cure the epoxies vary depending upon the application and the user's resources. Most home-based applications use a UV spotlight or tabletop lamp. Industries may use bench-top lamps, focused-beam lamps, lights integrated into conveyor systems, and other equipment.
Often businesses use specialty UV epoxies. Some companies use epoxies with dyes that fluoresce so that the workers can see if the epoxy is properly applied. Other special epoxies include cationic and acrylated epoxies. Cationic UV epoxies continue to harden when the UV light is off, while acrylated UV epoxy cures only while exposed to UV light.
Some common uses for UV epoxies include dentistry, optical equipment, and metal bonding. Often people use UV epoxies in making glass stemware, DC motor assemblies, and bonding clear acrylics and other plastics. In addition to bonding, people may use UV epoxies as sealants. Many manufacturers use UV epoxy resins to seal decorator items, such as key fobs, magnets, and pins. UV epoxies work well with photographic paper.
Users need to consider some health concerns when working with UV epoxies. The UV epoxy and its fumes may be a mild skin and eye irritant. A person should wear safety glasses or goggles to protect his or her eyes from splashes. If the chemical does splash into the user's eyes, he or she should wash the eyes thoroughly with water and seek medical treatment promptly. Users should avoid prolonged skin contact by wearing gloves and should clean the exposed areas with warm water and mild soap.