induction heating service,induction heater,induction heating equipment and induction heating system are supplied by DaWei Induction Heating Machine Co.,Ltd
Induction heating is a form of non-contact heating for conductive materials, when alternating current flows in the induced coil, varying electromagnetic field is set up around the coil, circulating current(induced, current, eddy current) is generated in the workpiece(conductive material), heat is produced as the eddy current flows against the resitivity of the material.
Induction heating is a rapid ,clean, non-polluting heating form which can be used to heat metals or change the conductive material’s properties. The coil itself does not get hot and the heating effect is under controlled. The solid state transistor technology has made induction heating much easier,cost-effective heating for applications including soldering and induction brazing ,induction heat treating, induction melting,induction forging etc.<
Induction Welding Process
Induction welding, also called electromagnetic or EMA welding, uses induction heating from radio frequency (typically 2 – 10 MHz) alternating current to magnetically excite an implant placed at the joint interface of the two parts being welded. This implant, or gasket, is normally a composite of the polymer to be welded with either metal fi bers or ferromagnetic particles. The heat generated melts and fuses the implant with the surrounding material. It is a reliable and rapid technique, ranging from fractions of a second for small parts to 30 – 60 seconds for parts with long (400 cm; 157 inches) joint lines, and results in structural, hermetic, or high-pressure welds [1, 2] . The two most commonly encountered mechanisms by which heat can be generated by an induction fi eld are eddy current heating and heating due to hysteresis losses. In eddy current heating, a copper induction coil (work coil), which is connected to a high-frequency power supply, is placed in close proximity to the joint ( Fig. 11.1 ). As electric current at a high frequency passes through the work coil, a dynamic magnetic fi eld is generated whose fl ux links the implant. Electric currents are induced in the implant, and when these are suffi ciently high to heat the conducting material, the surrounding thermoplastic parts soften and melt. If pressure is applied to the joint, this aids wetting of the molten thermoplastics, and a weld forms as the joint cools [3, 4] .