Effect of UV Radiation by Projectors on 3D Printing

Abstract

Polymers that solidify under light radiation are commonly used in digital light processing (DLP) 3D printing. A wide range of photopolymers use photoinitiators that react to radiation in range of ultraviolet (UV) wavelength. In the present study we provided measurement of radiant fluence in the UV wavelength range from 280 nm to 400 nm for two data projectors and compared effect of radiation on quality of 3D printing. One projector is commonly used DLP projector with high energy lamp. Second one is an industrial projector, in which RGB light emitting diodes (LEDs) are replaced by UV LEDs with wattage at the level of 3.6 % of the first one. Achieved data confirmed uneven distribution of radiant energy on illuminated area. These results validate, that undesired heating light causes internal stress inside built models that causes defects in final products.