Mill & foundry workers of the molten metal industry face no shortage of potential on-the-job hazards, not the least of which is extreme radiant & infrared heat emitting from the molten materials. Common PPE in steel and other types of mills include aluminized suits & gloves, hardhats, and heat reflective face shields. In addition to the extremely high temperatures, bright light emitted from the molten metal can be harmful to the worker’s eyes. Over the years, Paulson has developed specific PPE for mill & foundry workers to protect against both extreme temperatures and UV/infrared light.
What is the Sodium Line?
The “sodium line” refers to a specific wavelength of light emitted by sodium atoms when they transition from a higher energy state to a lower one. When a metal is in a molten state, the atoms are highly energized due to the increased temperature. As a result, the molten material emits light of various wavelengths, including the characteristic yellow light associated with sodium-based slag that rises to the tops of ladles containing the molten metal.
To block out this bright yellow light, workers of the molten metal industry often use shaded cobalt blue lenses. Cobalt blue is a specific shade of blue that filters out certain wavelengths of light while allowing others to pass through. Cobalt blue lenses selectively absorb light in the yellow region of the spectrum, including the wavelength emitted by the sodium atoms in molten metal. When light passes through the lens, the cobalt compounds absorb and attenuate the yellow light emitted by sodium, preventing it from reaching the eyes. At the same time, the lens allows other wavelengths, such as blues and greens, to pass through with minimal absorption. The optical filter created from a cobalt blue lens cancels out the yellow component of the light. As a result, the worker can see the molten material without the dominant yellow tint caused by sodium light. It’s important to note that shaded cobalt blue lenses may not eliminate the yellow color, especially in intense sodium lighting conditions. However, they significantly reduce its intensity and make the light more tolerable for the human eye.
Nanoparticle Cobalt Blue Face Shields by Paulson Mfg.
Using advanced materials science, including nanotechnology, Paulson has developed the only shaded cobalt blue face shields on the market for the molten metal industry. The polycarbonate base material of the shields provides excellent heat and impact protection, while the nanoparticle cobalt blue formulation meets the visible and IR transmittance requirements of ANSI Z87.1. Available in welding shades 3 – 9, the cobalt blue provides excellent eye protection from the intense and often harmful bright yellow light of the sodium line.
To learn more about Paulson’s next-gen nanoparticle cobalt blue face shields for the molten metal industry, please contact us today.