Carbon IR yielding energy efficiency gains

Infrared emitters have been used successfully for decades in industrial heating processes, for drying paint, molding plastic and manufacturing solar cells. The carbon infrared emitter has been around since the 1990s, helping to save up to 30 percent energy in many processes.

Some of the infrared radiation is absorbed by the material, some is reflected and the rest penetrates the materials. Each material has its own absorption spectrum, i.e. the range in which the electromagnetic rays are best absorbed. If this range is optimized, the material heats up much faster and more effectively.

Switching to medium-wave carbon IR emitters saves energy

The wavelength of the infrared radiation has a significant influence on the process. Short-wave radiation penetrates deep into solid parts and heats them quickly and evenly. Medium-wave radiation is more effective on surfaces and is also very well absorbed by water, glass and many plastics and then converted directly into heat.

Switching to medium-wave carbon infrared heaters can help to save significant amounts of energy costs. Extensive tests show that carbon emitters require up to 30 percent less energy for drying water-based paints and varnishes than conventional short-wave emitters. This increases the efficiency of the drying process of such paint and coating systems compared to conventional short-wave emitters.

Fast drying with high surface performance

Conventional medium-wave radiators are equipped with a heating coil made of alloyed resistance wire made of iron, chrome and aluminum. They are very robust, reliable and have a long service life. Conventional medium wave infrared emitters achieve outputs of up to 60 kW/m2 and response times in the range of two to three minutes.

In the event of an unexpected belt stop, conventional medium-wave emitters must therefore be swiveled away or shielded at great expense to prevent damage to the surfaces of the fabric webs. These relatively long reaction times make them more suitable for continuous operation.

Carbon infrared emitters instead are equipped with a carbon band. They also emit very effective medium-wave infrared radiation, but also offer high area outputs of up to 150 kW/m2 and react to power changes within seconds. This means that carbon emitters can be reliably switched off immediately when the belt stops, for example. These combined properties have made the CIR carbon emitter unique on the market for years, because it combines the medium wavelengths that are important for coatings, glass and plastics with high output and very fast response times.

Carbon infrared heat for non-slip coatings

A UK company introduced a new type of high quality, non-slip tray coating that required a new production line. The new non-slip coating is a water-based solution that is applied to paper mats and then needs to be dried as quickly as possible, a task that is performed effectively and with high quality using carbon emitters.

Since installation, the infrared system has proven to be highly efficient. The fast response times of the carbon emitters ensure that in the event of an unexpected belt stop, an immediate shutdown protects the products from damage. After some time, the company upgraded the production line with a further carbon module due to the increased demand for the tray overlays and this has enabled a further 30 percent improvement.

Carbon infrared dries water on airbag fabric

Airbags International in the UK manufactures airbags and other safety materials from nylon 66. A coating of silicone makes the surface more slippery and means that the material can later deploy in a fraction of a second. However, nylon 66 is hygroscopic, meaning it attracts water from the environment and can reach a moisture content of between three and five percent. This moisture must be reduced before coating in order to ensure good adhesion of the silicone and optimum surface quality of the fabric. The necessary drying and preheating processes are solved with carbon infrared systems from Excelitas Noblelight, which are individually controlled and regulated.

Optical pyrometers measure the surface temperature of the fabric and then the power of the infrared emitters is adjusted via a controller so that the material dries optimally without suffering heat damage. The infrared heat therefore dries silicone coatings on plastic fabrics optimally and ensures that an airbag deploys quickly in an emergency.

By using the medium-wave carbon emitters, the heating of the airbag fabric is solved so efficiently that the system has already paid for itself after coating the tenth roll of fabric.

Carbon infrared emitters for wood-based materials

Laminated panels and worktops are available in a wide range of finishes and can be tailored for installation in retail and hospitality, education or healthcare environments.

At Carella in the UK, the cut chipboard or MDF panels are manually fed into a PUR hot melt bonding station where the adhesive is evenly applied to the surface. They are then fed to a laminating station where a melamine or Formica panel is placed firmly and precisely over the board and bonded to it. Tests had shown that the core of a panel had to be heated to ensure a good bond between the PUR adhesive and the panel materials. This could not have been achieved by increasing the ambient temperature. Hot air blowers were out of the question due to the associated dust generation. Tests finally showed that medium-wave carbon infrared emitters could provide the panels with targeted heat shortly before the start of the bonding process.

The infrared solution proved to be simple but effective. Owen Rosborough, Production Manager at Carella, explains: "We now have much better control over the lamination, so there are no adhesion issues, which means we have consistent quality and less waste. In addition, the infrared system has proven to be energy efficient as it only works when we need it."

Taking the sustainability approach further

The switch from solvent-based paints and varnishes to more environmentally friendly systems such as water-based or powder coatings also requires us to think ahead when it comes to paint drying. To save time, space and costs, it is worth looking for the right method for the desired drying process. Excelitas Noblelight offers the entire range of infrared radiation from near infrared NIR to medium wave carbon technology CIR and advises on the selection of the optimum emitters for the respective process.

Excelitas Noblelight GmbH
www.noblelight.com