NIR-radiation spectrum

The underlying principle of NIR-Technology resembles the way a microwave oven works. Microwaves activate the water molecules directly, in contrast to a conventional oven that has to heat up before the energy reaches the target costing or substrate. However, NIR-Technology's electromagnetic waves have an effect not only on water, as do microwaves, but also, at the highest energy density, molecules of various substances. As a result, NIR-Technology can be implemented in a multitude of industrial processes using near-infrared radiation.

Comparison Transmission NIR and IR at PET

NIR stands for Near InfraRed. This part of the shortwave spectrum lies just above the visible light. This is where the wavelength of electromagnetic radiation reaches its maximum energy density and optimum physical characteristics. Proprietary NIR technology now makes it possible to use the unique physical properties of this part of the electromagnetic spectrum in industrial production processes for the first time.
 

inks & varnishes — function of the NIR- technology

The NIR-radiation energy quickly enters into the depth of the coating and keep water respectively solvents out of the whole coat thickness. With conventional infrared and thermo-air the energy predominantly is absorbed at the surface and will be slowly conducted into the coating.

There is a similar process with powder coatings and plastics. The powder constantly is heated, smelted and cured over the entire thickness of the coating. As there is no conduction of heat process with NIR-technology, powder coatings can be smelted and polymerised within seconds instead of minutes.

Comparison drying process NIR, IR, UV and induction

plastics — function of the NIR- technology

When heating plastics, the unique features of a small section of the electromagnetic spectrum is needed to conjure up that magical word “efficiency”. Just above the visible spectrum, in the near-infrared range (NIR), radiation reaches its maximum energy density. Completely new heating processes are possible here, making processes much easier to control than is possible with conventional technologies. The energy from the radiation is targeted very efficiently to the exact spot where it is required.

In the NIR range, plastics have a high radiation transparency. The beams immediately penetrate deeply and heating is performed rapidly and evenly with extremely short processing times. There is also a clear reduction in energy consumption because the system does not have to be preheated. What is more, it takes up a lot less space. Shorter heating paths also enable optimum integration into production machines and equipment. An integrated control loop also reduces the number of rejects produced.
 
When heating plastics, NIR radiation achieves more or less uniform levels of penetration. Infrared radiation essentially heats the surface, from which heat is then transferred.

Comparison NIR IR heating process preforms

printing — function of the NIR- technology

There are Two phenomena arising when using NIR-technology for drying of ink-jet printed paper. First of all the ink has a high absorption whereas the paper has a high transparency of the NIR-radiation.   The ink absorbs the energy and will be dried within seconds whereas the paper staysalmost cold. The energy is only effective where it is necessary. So the need for cooling the paper  is almost eliminated 

Comparison NIR, IR, hot air and printing applications