In scientific terms, Infrared, like light is a part of electromagnetic spectrum. As seen in the figure, it lies beyond the red part of the visible light. The Infrared spectrum starts at 0.7 µ (micron) and extends upto 1000 µ, although for heating purpose wavelengths only upto 10 µ are relevant.
Infrared waves emitted by IR emitters generate heat in the object internally by vibrating the molecules of the object. This is completely different from conduction and convection modes of heat transfer.
Improved output quality due to prevention of contaminationAs IR does not need a medium to heat, issues associated with air quality are minimized or eliminated. In finishing processes like paint / powder or lacquer curing, heating without air recirculation leads to a superior finish as there is no contamination by airborne particles. Many finishing processes have been converted to Infrared due to quality advantage alone.
Also in food processing it reduces the bacterial load and dust particles from air getting into the food material.
Improved quality due to penetration of infrared into the object.IR penetrates coatings on solid surfaces and removes the moisture / solvents from inside, thus eliminating pin holes in finishing processes.
This property of penetration helps achieve complete drying in case of paper/ cloth / technical textiles etc.
THE ENERGY SAVING ADVANTAGE
Single Stage Heat transfer .
Infrared is single stage heat transfer (emitter 🡪 object) as against multiple stages of heating required in other processes (fuel 🡪 heat exchanger 🡪 air 🡪 object). This is why the net efficiency of other processes is low. This also explains why, despite electricity being more expensive as a fuel, Infrared also offers energy cost benefit in many cases in addition to other advantages.
No loss due to Exhuast .
Also as IR does not employ air heating, in drying processes the moisture can be exhausted without any loss of efficiency
COMPACT FOOT PRINT
Extreme compact machines
Infrared works on the principle of optics i.e. it heats the area it is incident on. This property has produced a host of applications mainly to correct issues in exiting process.
In paintshops, IR is used for touch up curing after all upholstery is mounted.
In paper industry and many web processing IR is used for edge correction i.e. providing extra drying in edges which have slightly higher water content.
Applications like thermoforming present with a unique challenge that can only be met by Infrared. Materials in sheet form need to be heated in a kind of matrix arrangement where each zone can be as small as 200 x 200 mm. each zone needs to be set independently. This can only be done by IR.
PRODUCTIVITY AND AUTOMATION
IR emitters need a few seconds to get switched ON and OFF. This helps increase productivity as no heat-up time is required everyday. Also the oven can be switched off during small breaks such as lunch breaks. As there is no idle running, IR is particularly suitable for intermittent production. This feature also makes IR suitable for automation. The IR oven / dryer can be programmed to switch ON automatically just as the product enters it.
No other heating method can match the fine controllability of electric IR. Because of low thermal inertia, the response to any new control signal is instantaneous. This means the actual product temperature can be controlled even in 1 ⁰C in case of critical processes. This ability of IR has been effectively used in critical aerospace applications to create pre-planned temperature profiles on object surfaces.
REMOTE ACCESS AND INDUSTRY 4.0 FEATURES
A combination of all above properties, features and benefits puts electric IR in a different class by itself. Because of Ethernet connectivity and instant controllability of IR equipments, on-line program changes are possible even for installations outside the country.