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OCTOBER 2019 I PCB007 MAGAZINE 33 Figure 9: Energy comparison diagram. To make a realistic im- age of what is explained here, we took thermogra- phy on one of the platens from conventional press technology, and another thermography of the new magnetic press technol- ogy (Figure 8). The left side shows the hot platen heat distribution where the platen surface and the sides (mechanical links to the press guides) are hot while the center (press stack) is cooler and needs more time to transfer the heat through the press stack materials. The right side shows that platens are at almost ambient room temperature while the center of the press stack is hot. Energy Efficiency This technology not only delivers very uni- form temperature in the X-, Y-, and Z-axes of the press stack, but there is also another im- portant point to be emphasized. The energy efficiency of this technology is very high com- pared to conventional technologies. The expla- nation for this is that the traditional systems heat up large metal masses so that these large masses can transfer the energy to the material to be heated, which has much lower mass by comparison. To give you an idea of this perfor- mance, a representative example was prepared that attempts to quantify the amount of ener- gy needed to heat up the platens of a single- opening conventional press as compared to the electromagnetic inductance system (Figure 9). The necessary energy to heat up a given mass is defined by the equation: Where: Q = energy (J) Δt = thermal increase (Kelvin) Mass = mass to heat up (kg) λ = specific heat (J/kg·ºK) The traditional or conventional system heats up both M1 platens to transfer the temperature to M2 and M3 through isolation papers (yellow color) to prevent thermal shock. The electro- magnetic inductance system heats directly on- Figure 8: InduBond electromagnetic press technology versus conventional technology.