Infrared Application of the Month:
Thermal Simulation on Printed Circuit Boards
A manufacturer of printed circuit boards needed to test the thermal strength of its PCBs. They sought a means to test the circuit board's reaction to heat in a controlled lab situation so that results cold be measured, and needed adjustments (if any) could be made to the products before putting them into production. The manufacturer chose carbon infrared heat lamps from Heraeus Noblelight. The IR heaters simulated real-world situations and helped the manufacturer collect data regarding product topography, out-of-plane- and in-plane deformation.
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Infrared Application of the Month:
Tube Preheating with Omega Heaters
A flexible tube production facility needed a method by which they could heat tubes prior to bending and forming. Any heat solution would have to apply heat evenly and allow quick and precise control. Omega infrared heaters from Heraeus Noblelight met all of these requirements and more. Heraeus' patented gold reflector provided targeted, efficient heat directly where it was needed.
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Tech Center Spotlight:
Shortwave Heaters
Fast and Intensive
Shortwave IR heaters from Heraeus are suitable for all applications in which the attainment of high temperatures in the shortest possible time is what counts. Their emission maximum is between 0.9 and 1.6 micron.
Performance advantages include high radiation density in the most compact space; near-instant heating-up and cooling down times; optimized reflection; much more.
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Special Designs:
Spiral Heaters
With heaters in spiral form discs, tubes or rods made of plastics, metal or glass can be heated homogeneously. Compared with conventional heating methods, spiral heaters can provide savings in energy, time and costs. Heraeus offers a wide range of heaters for special applications.
Click HERE to download a brochure on Heraeus spiral heaters.
A wide assortment of other special design heaters is available from Heraeus. Click HERE for details.
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Technical Learning: Workpiece Characteristics and Their Effects, Part 2
Effect of power intensity
The flexibility of the corridor type of oven to change the heating condition significantly by
altering power intensity can be used to good effect in several ways. For example, reduced
power intensity is more suitable for workpieces of mixed gauges. Different heat settings
along the length of an oven may suit the curing of certain solvent-based coatings. The heat
transfer falls with distance as an inverse linear law, that is heat flux is inversely proportional
to wall separation.
Effect of conductivity
No significant temperature differences can be expected to occur when heat at the level
experienced in an infrared corridor oven flows into the core of a heavy metal item or across
a section heated on one side only.
Effect of product rotation
For the general case the number of revolutions made by a workpiece or loaded jig while in
the oven is the important criterion rather than the speed of rotation. A value of
approximately 10 revolutions produces a very acceptable temperature uniformity which is
comparable with that to be expected in convection oven practice.
Heating time compared to conveyor speed and product thickness
The time required to cure powder coating is virtually proportional to thickness of the
workpiece. A variable speed conveyor provides a method of maintaining maximum
production over a range of metal gauges.
Velocity and temperature of air
The main advantage of introducing fan circulation into an infrared oven is not to increase
heat transfer but to ensure uniform air temperatures from hearth to roof. The natural
tendency for air to stratify into hot and cooler layers is therefore negated. Circulation of air
at or close to the required temperature also has the advantage of optimizing temperature
uniformity on the product. It can also be observed on the trace of the run that the
workpiece starts to heat before entering the oven, This is encouraged by having extended
entry and exit reflective vestibules or doors of a reflective material which can be adjusted
to enhance reflectivity, Even in the open state parallel to the track the doors form an
effective infrared vestibule. For narrow work such as thin sheets they may be almost closed
to enhance heating inside the oven.
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That's it for this month's issue of Application Notes for IR Heating. Feel free to encourage your colleagues to subscribe. Just click HERE to send them an invitation to subscribe. It's quick, easy, FREE, and no-obligation.
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