UV (Ultra Violet) is invisible light. Human eyes are able to see only parts of the light spectrum, as the ear is able to hear some sound frequencies.
Human eyes are able to identify light with 750,000,000,000,000 to 429,000,000,000,000 of frequencies.
Human ears are able to hear 20 to 20,000 cycles per second.
Listen to 150 cycles per second
Listen to 500 cycles per second
Listen to 1000 cycles per second
Listen to 5000 cycles per second
Listen to 10000 cycles per second
Light
Each color is in fact a light which our eyes distinguish. cycles per second is referred to as Hertz (Hz). The hertz (symbol Hz) is the SI unit of frequency defined as the number of cycles per second of a periodic phenomenon. However, for the light, it is referred to as wavelength.
Light has been divided into 3 types:
- Ultraviolet (UV)
- Visible light which is visible to human eye
- Infrared (IR)
Changing the light frequencies, results in changing its effectiveness and features.
An object being exposed to the infrared light will get warm. It is used in physiotherapy as well for warming the body joints. Infrared light can transfer heat to the body.
When ink is being called as IR, it means that it gets dried by heat. If this heat would be supplied by getting exposed to the IR light, the ink will be dried faster and better.
If you feel hot in front of fireplace, it is because of the infrared light; however, if you feel warm by putting our hand on the heat, it is because of hot air transferred to your hand. So, there would be different between air dryer and infrared one.
However, Ultra Violet light has its own effects. For example, your body gets tan because of the UV in the sunlight. The harm to your eyes is caused by exposure to UV radiation from Argon electro arc welding. When talking about UV ink, we mean that it gets dry by exposure to UV light.
UV ink is converted from liquid to solid in a fraction of second. The increasing causes of its usage are as following:
- Very fast drying has caused the UV dryers to be smaller
- IR inks made a lot of problems because of unwanted drying. Using UV inks solves the problem. UV ink will not get dried until exposing to the UV light.
- UV dryer consumes less power than IR dryer.
Dangers of UV Light
The main danger is exposure of UV rays to human eye.
Symptoms include increased tears and a feeling of pain, likened to having sand in the eyes. Symptoms tend to occur a number of hours after exposure, and typically resolve spontaneously within 36 hours, although constriction of the pupils may last as long as 96 to 128 hours in some cases.
The injury may be prevented by wearing eye protection that blocks most of the ultraviolet radiation, such as welding goggles with the proper filters, a welder’s helmet, sunglasses rated for sufficient UV protection, or appropriate snow goggles. The condition is usually managed by removal from the source of ultraviolet, covering the corneas, and administration of pain relief.
The second danger is conversion of Oxygen to Ozone which is a poisonous gas. Ozone is sometimes used for sterilization. All machinery have a gas vacuuming system for removing Ozone which needs to be checked from time to time to ensure that all the way to out is not closed. Of course, ozone is converted to oxygen after a short time.
