Whelen Engineering Company, Inc.

Our Hard-Coating Process

At Whelen, we utilize an industry-first process to counteract the effects of environmental and chemical damages to our lenses and domes. We hard-coat as many as 35,000 lenses every 24 hours in our New Hampshire facility! It takes just 15 minutes for a lens to make it through the entire process.

Why we do it

Our products feature UV resistant polycarbonate lenses, but we hard-coat for added durability and reliability. Raw, injection-molded plastic begins to degrade when exposed to the environment immediately. Our hard-coating increases the visual life of the light to 7-10 years, providing UV and scratch resistance from sand, salt, sun, and road chemicals.

How we do it

  • We begin by placing raw lenses and domes, composed of UV resistant polycarbonate, onto custom fixtures in the loading area.
  • In the cleaning station, the lenses are washed with isopropyl alcohol to clean their surface and remove any debris.
  • The lenses then move into the spray off area to remove any static charge from their surface.
  • Next, our six-axis robot uses an atomizing spray gun to apply the actual hard-coat in a clean, stainless steel environment. It’s completely free from outside contaminants.
  • Then, the infrared heating oven heats the lenses to 160°F, breaking the chemical bond and infusing the hard-coat into the lenses.
  • The lenses move to the UV lamp oven, which utilizes 20 high-intensity UV lamps to solidify the hard-coat.
  • Next, the lenses arrive in the unloading area, where a spectrometer measures the thickness of the hard-coat. Finally, the lenses are inspected and sorted by our team.