When three-dimensional parts of different shapes and sizes, angles, bends, edges, and bumps are cured by UV LED light, light is required to be projected on all surfaces, and there should be reliable and sufficient energy. Generally, a lamp is composed of a lamp tube and a reflector. The reflector is used to gather the light beam and project it on the object. The reflector is generally elliptical or parabolic. Use an oval lampshade. The lamp tube is placed at the first focal point of the ellipse, and the light is focused at the second focal point to form a narrow and high-amplitude beam. However, due to the divergence of light, after deviating from this point, the radiance decreases rapidly. Using a parabolic lampshade, parallel ultraviolet beams can be obtained in a wide range, but the irradiance is low and shadows can be added to three-dimensional objects. In order to fully cure the entire surface, some measures need to be taken: one is to improve the shape of the oval lampshade, change the focus of the light, and make it farther away from the lamp surface.
Make the focal plane wider, although this will reduce the peak of high radiation, but can make the intensity of the light more uniform, and sufficient radiation can be obtained far away from the lamp, while maintaining the advantages of focusing and diverging light. Reduce the appearance of shadows; the second measure is to optimize the formula; the spectral absorption of the paint should match the light emission spectrum of the lamp; the third is to optimize the industrial conditions, and the energy of the ultraviolet light projected on the object should match the processing speed; the sensitivity of the paint And the thickness of the coating should be optimized, so that the surface coating can be cured within a large range of light intensity changes.
Of course, there are also special requirements for 3D curing devices. The production line should be designed according to the actual situation such as the size and shape of the object, whether the object is vertical or horizontal, and whether the potential shadow parts can be illuminated by rotation. For the purpose of UV LED light curing, capacity requirements and curing speed adjustment, it is an important method to install the lamp source on the robot. There are many advantages to using a robot, and many parts that cannot be illuminated by a fixed light source can be effectively illuminated. As mentioned earlier, the weather resistance of coatings made of glass fiber reinforced plastics for the car body is many years higher.
