Infrared heat can help joining plastic parts in different ways: by the activation or curing of an adhesive, by hot staking or by plastic welding. In plastic welding, a thin surface layer of the plastic parts is melted, which can then be joined simply by pressing them together. Infrared welding can be a beneficial replacement for certain traditional hot-plate and vibration welding applications. The use of a controlled IR heat source (emitter) with accurately regulated time and temperature in a precise location allows more accurate process control on plastic assemblies. Different heat levels for varying welding conditions can be accomplished on a single fixture. The ability to place the infrared emitters in various positions makes it possible to weld multiple surfaces in one setup.
Because the infrared heat source does not touch the part, the process is cleaner. Unlike the hot-plate process, plastic does not stick to the heat source. The downtime required to clean or remove a hot plate two or three times per shift is eliminated. With the instant-on of infrared emitters, no time is wasted waiting for tooling to heat up. New setup changeover happens faster because you don't have to wait for tooling to cool down (as you would with hot-plate setups).
There are several cost reduction opportunities with infrared welding systems. Capital investment is reduced. Backup tools are not needed. An IR welding machine takes up less floor space, and electric consumption is much less. Injection molding tooling costs can be reduced since tongue-and-groove part designs for surface joining requirements are eliminated.
Heraeus infrared emitters are matched exactly to each process step. Flexible designs also allow matching with complex geometry parts. Plastic components are efficiently fastened together in a few seconds because heat is applied to precisely the right point within a given time.
