The hazardous of metal powder in 3D printing
 

SLM technology is the main solution of metal 3D printing procedure. When the laser to melt metal powder, accompanied by the production of soot, if cannot be handled timely , the smoke will be under the disturbances of heat flow attached to the forming parts, or in laser forming on the surface, forming area will be polluted, 3D work-piece will be worse caused. If too much smoke, may cover laser lens, even make it burned. The soot contains not only the smoke from laser sintering, but also half-melted metal powders and even some solidified large particles. No matter what kind of powder, their chemical activity and residual energy is very high, so that the captured smoke and dust has inflammable and explosive, when these substances contact with the outside air, easy to occur combustion or explosion reaction.

Principle and difficulties of atmosphere circulation filtration system for metal 3D printing

The atmosphere circulation filtration system is a main peripheral equipment of the metal 3D printer. Its principle is to generate negative pressure by blower, quickly take away the dust and isolate the dust through the filter device at the inlet end, and return the cleaned gas to the chamber to create a stable circulation process. In this cycle, it is necessary to design different kinds of dedusting and filtration methods to filter out impurities with different particle sizes, such as large particles, powder and flue gas at the same time. At present, the commonly used filtration devices are relatively simple, and most of them only use one circular filter. In addition, the shutdown and replacement of filter will interrupt the laser process, destroy the inert gas, and restart the equipment will affect the airflow uniformity, which will easily lead to the failure of parts process. If you want to avoid stoppage, it is necessary to predict the status of the filter element in time and replace the filter element in advance, which will lead to low efficiency. The filter needs to be taken out of the equipment when it is replaced. Once the dust is exposed to the air, spontaneous combustion is easy to occur. How to effectively avoid the dust exposure and timely inert treatment is a major difficulty in the design.
 

TAF-10 Metal 3D printing air circulation filtration system

Zhejiang TOP as metal 3D printing peripheral equipment manufacturing experts, for many years continuously thorough field investigation, collect question, and solve for customers. The new TAF-10 atmosphere circulation filter system, modular design of multi level filters, completely solve the problem of 3D printing process, half reduced the filter replacement frequency, to completely eliminate the soot particles or filter combustion, change filter without stop machine etc.

The TAF-10 atmosphere circulation filtration system adopts a three-stage filtration system for graded filtration in the case of dust particles of different components with different particle sizes. At the same time, different explosion-proof treatment measures are adopted for dust substances with different hazardous levels. The large particle size dust produced by primary filtration is recovered by sand filling, and the spontaneous combustion of particles can be effectively prevented by timely burying. The saturated filter cylinder produced by secondary filtration is treated with neutralization liquid inerting to ensure the safety of filter replacement. At the same time, the powder bin and filter adopt modular design, can make online non-stop replacement, which not only improves the printing efficiency but also facilitates the cleaning, improves the interchangeability and reduces the cost. In addition, the product is equipped with an automatic oxygen content monitoring system during the circulation process. When the oxygen content exceeds the standard, inert gas is automatically added to ensure the printing quality. Multi level sensor is installed to realize automatic material detection and timely alarm. Real-time monitoring of the inside and outside of the filter is carried out by differential pressure sensor, and automatic back blowing is carried out to prevent the filter from blocking and extend the service life of the filter. The equipment is also designed to a perfect grounding system, meets the explosion-proof standards.
 

The modular design of the TAF-10 atmosphere circulation filtration system is not only to meet standard requirements, but also accept customer design development. At the same time of solving customer needs, we always adhere to the spirit of the craftsman, innovation as the foundation, while providing quality products to achieve win-win cooperation with customers.