As we have already mentioned in the article The ABC of UV curing technology, the process for using UV products is very simple. However, despite this, the product’s technical data sheet must be consulted before use and the following basic points should be taken into account:
The recommended PPE must be used at all times. In general, protective goggles for application and mechanical protective gloves, as well as UV-filtering goggles for the use of the UV lamp, such as the Robled lamp.
If the product is applied by spray gun, an opaque container must be used to prevent light from coming into contact with the product. Otherwise the product would start the photochemical reaction and dry inside the container.
The curing time depends on the specifications of each product and UV lamp used. Before starting the curing process, the curing time of the product used must be checked in order to adjust the lamp accordingly. It is also recommended to remove the masking paper in order to obtain proper curing of edges and blurred areas.
Curing is carried out with a specific lamp that projects UV light. There are currently two types of technology, mercury vapor technology, which requires pre-heating before use, and modern UV-A/LED curing technology such as Robled, which eliminates this need and offers higher power and lower energy consumption.
In addition, manufacturers can provide different lamp sizes to optimize curing according to the extent of the damage. Therefore, when using the lamp, the operator must take into account the technology of the lamp to determine whether it requires preheating or not, choose the size that best suits the work being done and determine the application distance of the UV light.
The UV curing of the product can be done statically, i.e. without moving the lamp, mainly in cases where the damage is medium or light in size, or in motion when the area is larger or a hand-held lamp is used. It should be noted that the curing time may increase for curing in motion, to ensure that the light impacts the entire area for a sufficient time.
During the curing process, it is essential to maintain the lamp perpendicular to the shape of the part, as well as the recommended curing distance, in order to obtain the ideal light diameter.
As an example, for ROBERLO’s HALLEY UV200 primer, if we place the UV curing lamp at a distance of 10cm, the diameter of action of the LED light is 18cm and drying times of just 30 seconds are obtained. If placed at a greater distance – at 56cm from the part – the diameter of action will be larger, but the light intensity will be lower, so the drying time will increase to around 2 minutes.
Curing times should be increased proportionally when one or more of these circumstances occur:
- Product thicknesses greater than those indicated in the product data sheet.
- Use of lamps with an intensity range below the dominant wavelength range (395 nm).
- Curing of very large surfaces, generally all surfaces larger than 50 x 50.
Improving service and profitability
UV curing products have improved their performance over the last few years, becoming an alternative to traditional products. Their popularity has grown due to their efficiency and simplicity of application. As a result, bodyshops with a higher volume of work can improve their vehicle flow and offer a service with shorter repair times.