Tinted Triacetate

Specifically developed for applications involving high radiant energy with levels of glare that would impair clear vision, our green tinted Triacetate visors provide excellent optical assistance during operations in front of such high glare sources as welding or thermal spray equipment. 

The green tinted Triacetate Optical Coating Technologies manufactures and supplies for use in welding and arc spray visors meets international Shade Levels (see the Technical page). The use of the correct eye protection when welding or using arc spray equipment is essential. Not using adequate eye protection is dangerous as it allows harmful ultra-violet (UV) radiation to reach the eye.

UV radiation is divided into three wavelength ranges

• UV-A (315 to 400 nm)
• UV-B (280 to 315 nm)
• UV-C (100 to 280 nm)

UV-C and almost all UV-B are absorbed in the cornea of the eye. UV-A passes through the cornea and is absorbed in the lens of the eye.

UV radiation can produce an injury to the surface and mucous membrane (conjunctiva) of the eye. Commonly called "arc eye", "welders' eye" or "arc flash", the proper name for the injury caused is conjunctivitis. Conjunctivitis is an inflammation of the mucous membrane of the front of the eye, the conjunctiva. The symptoms include:

• Pain, ranging from a mild feeling of pressure in the eyes to intense pain in severe instances.
• Tearing and reddening of the eye and membranes around the eye.
• A sensation of "sand in the eye" or abnormal sensitivity to light.
• The inability to look at light sources (photophobia).

The amount of time required to cause these effects depends on several factors such as the intensity of the radiation, the distance from the welding arc, the angle at which the radiation enters the eye and type of eye protection that the welder or bystander is using.

However, exposure to just a few seconds of intense UV light can cause conjunctivitis. It is possible that these symptoms may not be felt until several hours after exposure. Long term exposure to UV light can produce cataracts in some persons.

Welding and arc spraying also gives off intense visible light and infra-red (IR) light. IR light is found in the 700 to 1,400nm wavelength range. Visible light from welding or arc spraying is very bright and can overwhelm the ability of the iris of the eye to close sufficiently and rapidly enough to limit the brightness of the light reaching the retina. The result is that the light is temporarily blinding and fatiguing to the eye.

A more serious concern is the temporary or permanent scarring of the retina due to its sensitivity to blue light, around 440 nm wavelength. Exposure to infrared light can heat the lens of the eye and produce cataracts over the long term.

And of course the welder or arc sprayer has their facial skin exposed to the arc radiation.
UV radiation in a welding arc will burn unprotected skin just like UV radiation in sunlight.
Long term exposure to UV radiation can cause skin cancer. IR radiation and visible light normally have very little effect on the skin.

To find out which is the best solution for your tinted Triacetate needs, call Optical Coating Technologies on 01827 63489 or email us on info@optical-coatings.com.