Infrared radiation (IR) and acrylic
Infrared radiation is the long wavelength radiation beyond the sensitivity of the eye, ranging from 700 to 1,000,000 nanometers. Its source may be the sun, infrared heating elements or any hot object. Each type of infrared radiation is characterized by a specific range of wavelengths. We are primarily interested in the near infrared range (NIR) from 700 to approximately 10,000 nanometers.
Incandescent lamps and infrared heat lamps emit radiation in both the visible and infrared spectra. A major portion of energy, especially in the case of infrared heat lamps, is radiated at wavelengths above 700 nanometers. As the temperature of the energy source decreases, radiation is emitted at longer wavelengths.
All solar radiation as well as artificially created radiant energy will be converted into heat when absorbed and re-radiated by any material.
In the penetrating infrared band from 700 to 1400 nanometers, clear 3mm ACRYLITE® cast (GP) acrylic sheet or 3mm ACRYLITE® extruded (FF) acrylic sheet transmits approximately 90% of infrared radiation - see the chart below. The transmission rate decreases slightly with increasing thickness. In the 1400 - 2200 nanometers range, ACRYLITE® cast (GP) and ACRYLITE® extruded (FF) sheet transmit radiation at a gradually decreasing rate; at 2200 nanometers, transmission approaches zero.