When I tell people that I work for a manufacturer of UV curing equipment and parts, they usually have no clue what I am talking about. I then tell them about the benefits of UV and how UV curing is used in many familiar industries such as, printing, optical fiber and hardwood flooring. Typically when people think of UV, they naturally think of UV from the sun and possibly even the dangers of skin cancer. However, not all UV is harmful. In fact, exposure to UV even has some health benefits and UV is used as a means of sterilization and disinfection in many hospitals.
This blog will explore UV and how it affects your everyday life, as well as the many benefits gained by manufacturers to improve their production processes and increase output.
Ultraviolet (beyond the violet) light was discovered by Johann Wilhelm Ritter in 1801. He conducted experiments with silver chloride on paper exposed to rays just beyond the visible spectrum on the violet end to prove that an invisible form of light existed where sunlight was not visible. Major advancements have been made in UV technology since 1801 and man-made UV radiation is now a well-established technology used in many manufacturing processes.
What is UV
UV is a type of radiant energy that appears on the electromagnetic (EM) spectrum between visible light and x-rays. It has a shorter wavelength than visible light but with higher energy (or frequency). To explain further, the EM spectrum is divided into seven regions based on wavelength and frequency/energy. Wavelength = distance between 2 peaks measured in nanometers. Frequency = number of waves over time, measured per second or Hz. Short wavelength = high frequency meaning wavelengths pass in shorter time (more shorter waves). Long Wavelength = lower frequency meaning wavelengths take longer to complete. (longer waves)
Seven Regions in order of decreasing wavelength.
- Radio Waves –Long waves used in communications such as radio, voice, data and other media.
- Microwaves – Heat source for Microwave ovens, radar and high bandwidth communication.
- Infrared –Invisible to human eye but can be felt as heat.
- Visible Light –Can be seen by the human eye.
- UV –Cannot be seen by the human eye and can be broken down further into V, A, B and C.
- X-Rays –Soft x-rays are produced by accelerating electrons. Dangerous.
- Gamma Rays – Hard x-rays produced by atomic nuclei and can kill cancer cells. Very dangerous.
- (EM Spectrum)
UV from the Sun vs Man-made
Sunlight contains only about 10% UV and only one third of that UV penetrates the earth’s atmosphere. Of that one third, 95% is UVA which has the least energy and is always present around us. It will tan your skin, causes skin cells to age and damages DNA. UVB accounts for the remaining 5% and is the UV that damages the DNA directly in skin cells and is responsible for causing sunburn, cataracts and most skin cancers.
UVC has the most energy but UVC from the sun does not reach the earth’s surface because it is blocked by the ozone. UVC damages and destroys genetic material. UVC is used to purify air and water and to disinfect and sterilize. UVC can be generated or produced by passing an electric current through vaporized mercury. Artificial (man-made) sources of UV light include tanning lamps, curing lamps, mercury vapor lamps and germicidal lamps.
Health Benefits of UV
The warmth of the sun brings out the best in most of us. It energizes us and improves our mood. Exposure to UVB from the sun promotes the production of vitamin D which has multiple health benefits including the production of serotonin. Vitamin D promotes better sleep, stronger bones, a healthier immune system and can lower blood pressure. Another benefit of UV is that it is used to treat certain skin conditions. PUVA is a light procedure that uses UVA light exposure in combination with a drug or cream and is said to cure vitiligo, eczema, psoriasis and lymphoma.
Common Everyday Uses of UV
UV is commonly used as a means of drying and disinfecting in services and products you are familiar with and purchase. UV is regularly used by dentists to cure resins on your teeth and it is also used to whiten teeth at the dentist’s office or at home. Nail salons use small UV heaters to quickly dry nail polish and UV printers have become standard in most offices and homes to instantly dry ink on paper. 3D printers also utilize UV. These methods of using UV are common to most people however, did you know that UV is also used to pasteurize juice and remove microorganisms in food? Apple cider and juice are treated with UV light to reduce the microbial pathogens. UV-C is used in greenhouse irrigation to purify contaminated water that is then used to clean lettuce, vegetables and fruit. Contaminated water can cause outbreaks of E. coli which result in widespread illness.
With the recent outbreak of COVID-19, many individuals and companies are purchasing germicidal lamps to disinfect their homes and offices. Due to the shortage of N95 respirators, UV has been offered as a solution to sanitize respiratory masks in hospitals. The NIH recently published a study that states N95 respiratory masks decontaminated with UV and VHP (vaporized Hydrogen Peroxide) can be reused up to three times as long as the wearer verifies that the mask fits properly.
Other Benefits of UV and UV Curing in Manufacturing
The benefits of UV curing used in manufacturing applications is constantly growing. Did you know that the decorated tin you use to store your Christmas cookies was most likely cured using UV? Many manufacturing processes utilize UV for the items you encounter on a daily basis. The basics, such as soda cans, food cans, aerosol hairspray, caps on bottles, lips on jars, toothpaste tubes, plastic & styrofoam cups, pet food bags, hardwood and luxury vinyl tile (LVT) flooring, magazine covers, cosmetic packaging, interior car trim, car windshields/headlights – even components of your cell phone have been cured using UV.
Manufacturers understand the benefits of UV in their processes. UV is a green technology because UV chemistries (inks, coatings, and adhesives) are almost always 100% solids, and therefore emit no VOCs (cancer causing Volatile Organic Compounds) into the atmosphere. Other competing technologies such as convention thermal drying processes will emit VOCs and other Hazardous Air Pollutants (HAPs) into our atmosphere which cause health hazards to people and harm our environment.
Depending on the application, adding UV lamps to a production line can save a company considerable space. Space always comes at a premium in a manufacturing facility. Typical conventional thermal drying ovens for high volume production lines can be 50 to 200 feet long depending on the application and process speed, whereas a UV curing chamber for the same types of applications will only consume about 3 to 10 feet.
A final benefit of UV technology is it will save manufacturers money and increase the bottom line. Implementing UV curing into a production line will almost always result in faster production speeds or much shorter cycle times, both of which result in significant increases in production and process efficiency. UV curing will typically allow the end user to produce a higher quality product. UV printing inks appear more rich and vibrant in color, making the packages more appealing. UV cured coatings have better physical properties than thermally dried coatings. For example, virtually all hardwood flooring and other solid surface flooring (like luxury vinyl tile) now have UV coatings on them to make the flooring scratch, moisture and stain resistant. Miltec UV manufactures UV curing equipment and spare parts used these applications and many others.
Miltec’s UV equipment is superior to competitors’ UV equipment because of its performance properties, including, higher peak irradiance output, higher UV energy output, higher curing efficiency, exceptional cooling, and lower IR heat output. Additionally, Miltec’s UV equipment has many user-friendly & maintenance-friendly features that utilize image-based operation and troubleshooting on a central touchscreen control system.
Miltec UV is the leader in the UV industry and has a reputation of providing the best performing UV systems available in the world. In addition to UV equipment, Miltec also supplies UV replacement bulbs, reflectors, and many other consumable parts for a wide variety of UV equipment made by other manufacturers. Miltec UV can be your one stop source for all your UV equipment, UV Lamps/parts, and UV technical support needs.
Written by Beth Mosner