Chemistry and the UV-curing process

All UV-activated gel products today are based on acrylates. Acrylates are a broad term for the chemistry behind many of the plastics around us. In the nail industry, what they all have in common is that they are most often found in a liquid, uncured form.

All of our gel products are UV-activated and require UV light at wavelengths between 365nm and 405nm to initiate the curing process. Nailster’s UV lamps emit UV light at these wavelengths to ensure proper curing.

When we talk about light and its different wavelengths, we enter the world of spectrography. Spectrography is the technique used to classify light according to its wavelength. The term "nm" stands for nanometer, where 1 meter equals 1 billion nanometers. The light we typically see from a household lamp falls within the visible spectrum, which ranges from 435 to 750 nm. By comparison, X-rays, which are used at the dentist, have a wavelength of around 1 nm. The wavelength defines the distance between two wave crests in the radiation, which means that for red light with a wavelength of 750 nm, there can be up to one and a half million "crests" in one meter.

Radiation is divided into different categories with specific names, such as X-rays, ultraviolet, visible light and infrared (the latter is experienced as heat). The UV light used to cure UV Gel Polish falls within the wavelengths of 365 to 405 nm, placing it in the ultraviolet spectrum, where it is often referred to as UV-A light.

UV lamps are often measured in watts, but this does not give an accurate picture of the lamp’s true UV intensity. Watts typically indicate the lamp’s maximum power consumption, which can be compared to judging a car’s performance by its fuel consumption. A more accurate way to measure a UV lamp is to look at its UV intensity. As this can be quite technical, UV intensity is rarely mentioned in the marketing of UV lamps.

The positioning of the LED diodes and the way the UV rays are reflected inside the lamp mean that the intensity varies depending on where in the lamp it is measured. The intensity is highest furthest inside the lamp, at a medium level in the middle, and lowest at the sides.

It is a common misconception that the heat from a UV nail lamp is what “dries” the nails. In fact, it is the UV light itself that cures the nail product. The warmth you feel is simply a natural effect that occurs because UV LEDs also produce heat when they emit light, much like a light bulb that becomes warm.

The curing process for all UV Gel Polish is exothermic, which means it naturally releases a small amount of heat as part of the chemical reaction. Normally, this is not something you will notice. However, in some cases, if a particularly thick layer of product has been applied or if your nails are more sensitive, you may experience a warm sensation.

If you notice a stronger heat sensation, it is important to proceed with care to ensure your comfort. We recommend pausing the curing process briefly and taking a short break. To make the process more pleasant, you can use the lamp’s “Low heat” function. This smart setting starts at a low intensity of around one-third of the full level and gradually increases the power to full capacity over the next 99 seconds. This helps minimize heat build-up, so you can continue creating beautiful nails in a comfortable and safe way.