3D printing affects indoor air quality research still needs further testing

Since 3D Printing became a reality in the 1980s, in just over 30 years, 3D Printing technology has penetrated into all aspects of social life. Industrial-grade 3D printers can be used for one-time molding of complex parts, which can not only reduce costs, but also maintain the unity of quality and accuracy between parts, and can also be used for rapid production of molds and improve production efficiency.

And desktop-level 3D printers have also been widely used in our daily lives. The working principle of 3D printing is to use wire plastic or other basic materials as raw materials, melt the material at high temperature, and print layer by layer according to the cross-section formed by the digital model. Commonly used thermoplastic materials are ABS resin, HIPS, polycarbonate, nylon and so on. During the printing process, the thermoplastic material melts at high temperature, which not only releases a variety of volatile organic compounds (VOCs), but also releases a large number of ultrafine particles (UFP, particles with a diameter of less than 0.1 micron), thereby reducing indoor air Quality, even harmful to human health. The VOCs released by different materials in 3D printing are also different. For example, ABS releases styrene. Toxic to the human nervous system, respiratory system, circulatory system, etc. Ultrafine particles can deposit in the lungs through breathing, and even enter the blood circulatory system through the alveoli, thereby harming human health. In the past few years, a number of studies have investigated the possible negative effects of pollutants released by 3D printing on human health, and some results have been obtained. For example, UL Chemical Safety and Georgia Institute of Technology conducted a two-year survey to explore the impact of desktop 3D printers on indoor air quality.

On December 15, at the 3D Printing and Emerging Materials Exposure and Risk Assessment Seminar, some new research results were released, which not only revealed the impact of ultrafine particles released by 3D printing on indoor air quality and public health, but also discussed these releases. The specific composition, particle size and residence time of the material. For example, a study by the National Institute of Occupational Safety and Health in the United States evaluated the toxicity of particles released by ABS resin to human lung cells. Research on 3D printing pollution emissions relies heavily on detection instruments. Among them, VOCs may need to be detected by mass spectrometry equipment. A study by the U.S. Environmental Protection Agency used a customized reactor and mass spectrometer (Thermal Diagnostic Research System (STDS)) to simulate the heating time, temperature, and oxygen concentration at the nozzle during the actual printing process in the reactor. Then use a mass spectrometer for analysis. The research of ultrafine particles in ambient air pollution already has a relatively mature technology and analysis system, which can integrate ultrafine particle counting and video recording. Through a similar system, researchers can analyze the distribution of ultrafine particles and the residence time in the air during 3D printing. At present, the research on 3D printing pollution emissions is still in its infancy, and there are fewer relevant domestic studies. Technology is one of the trends in the development of science and technology, and will be further popularized in production and life in the future. Therefore, the pollution of this technology to the environment and the damage to human health are problems that must be solved. There are some simple measures to help operators reduce the negative impact of 3D printing on indoor air quality, such as maintaining good ventilation, adding a housing for 3D printing, and waiting for the nozzle temperature to be set to the lower limit of the material temperature range. However, these measures address the symptoms but not the root cause. To completely solve this problem, we still need to start with the improvement of materials and 3D printing technology itself, and this requires us to upgrade our detection methods and have a deeper understanding of 3D printing pollution emissions.