Evaporation & drying of solvent-based paints with infrared

The evaporation of solvents from lacquers and the chemical cross-linking of lacquers can be accelerated or even started by the application of heat by means of infrared lacquer dryers. Three fundamentally different mechanisms are used in paint drying and heat transfer in general.

In infrared dryers, heat is transferred directly without a transfer medium. The infrared emitters are aligned for paint drying in such a way that only the component and its paint layer are heated. This and the heating without an intermediate medium result in a high thermal efficiency and higher power densities, which means that significantly shorter heating and drying times are achieved. The possibility of increasing throughput due to shorter process times or saving production space when designing a system are often decisive arguments in favour of infrared drying.

Furthermore, infrared drying systems are significantly faster reacting due to the lower thermal mass of the emitter sources, which guarantees advantages during recipe changes and start-up processes.

Infrared paint dryer for solvent-based paints - Combining EX protection with fast drying in a process-safe manner

When solvents or VOCs (volatile organic compounds) evaporate from the paint coating, there is a risk that explosive atmospheres may develop which can ignite on the hot surfaces of the infrared radiators.

IBT's thermoprocess technology division has developed a corresponding safety concept for this, taking into account the standard DIN EN 1539: 2016-02 ("Dryers and ovens in which flammable substances are released - Safety requirements"), and designed suitable plant technology for drying/painting plants. If the paint drying tunnel is designed in accordance with type A of the aforementioned standard, the VOCs are diluted to a level below the lower explosion limit (LEL) of the respective VOCs that is permissible in terms of safety. For this purpose, the maximum permissible mass flow of VOCs is agreed with the plant operator and the required exhaust air volume flow is calculated from this.

In a growing number of drying sections, infrared and convection are combined to combine both advantages and minimise the effects of the disadvantages. The heating section or intermediate drying section is equipped with infrared radiators and thus ensures short heating times. This is followed by the drying section with convection. Here, a homogeneous temperature distribution is achieved and the paint is dried at low operating costs.

Infrared paint drying systems in industry for your application

Whether primer, base coat, top coat or clear coat - IBT.Thermprocess has extensive know-how in paint processing/paint drying using infrared systems.

We support you in the new conception, equipment or retrofitting of your drying systems with infrared technology. The retrofitting of existing paint drying systems results in considerable cost savings compared to the purchase of a new system.

 


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