The classic FDM 3D printing process involves creating layers by depositing molten material, usually in the form of plastic filaments. However, a new method of using this manufacturing technology has recently emerged, shifting from coils to the use of particles or granules. Granular 3D printing is a 3D printing method that uses thermoplastics in the form of granules to make parts layer by layer. More and more companies are developing machines using this material, and even developing solutions for standard 3D printers to make them compatible with particles.
How does 3D printing with particles work?

Plastic granules are granular materials obtained through so-called granulation. In this process, the material (which can be a chemical, plastic, composite or mineral) is molded into a compressed form of particles. These types of resources are mainly used for injection molding, although as we mentioned, they are becoming more and more obvious in the field of 3D printing. It has been proved that compared with the number of existing spools, they are slightly less used in additive manufacturing. Although this may seem contradictory, because the filament is made of particles, using particles directly in printing will save an intermediate step in the whole process.

Granular and 3D printing
One thing to remember is that pellets and filaments need different extruders to meet your printing needs. Unlike filaments, the pellet extruder has an integral bowl that gradually absorbs the material and pushes it into the melting zone. There, the particles are softened to the desired consistency, then the plastic is sprayed through the nozzle and deposited on the printing platform. Although this process may seem a bit complex compared to filament extrusion, it has many very interesting benefits, as we will see below.

As for the main advantages of particle 3D printing, we found that the final cost of parts was significantly reduced due to low material cost and shorter manufacturing time. In this way, we have the ideal technology to produce long series or large parts, otherwise these parts will not be fully profitable. Another positive aspect is to reduce paper jams in the manufacturing process, because we can find a common printing problem when using filaments. Finally, using particle additive manufacturing can make multi-color parts by combining plastic particles of different colors in the same pallet.

But what is particularly interesting when dealing with particles is the final attributes that can be obtained. When using filaments, it is important to know that they do not have the same physical and chemical properties as the raw materials. In fact, when we make the filament, we need to heat the raw material, which in turn will reduce its performance - the more we heat, the more obvious the degradation. Then we must add additives to reduce this degradation. Therefore, the results obtained are completely different from the starting materials. However, by using particles from the very beginning, users do not need to experience these transformations, so that they can bypass these degradations and are closer to the chemical and physical properties of plastics used in injection molding.

In terms of disadvantages, it is worth mentioning that 3D printing of particles is not as popular as filament at present, so it may be difficult to develop extruders suitable for these materials. In addition, when parts are manufactured layer by layer, particles are not connected to each other like filaments, but are dispersed. This makes it difficult to control flow changes, which is necessary for more complex parts.

As we have seen, the growing popularity of granular 3D printing is encouraging many companies to develop their own manufacturing solutions. For example, the Chinese brand Piostreak particle 3D printer can meet the needs of each user, and can print a variety of particle materials on their G series particle 3D printer, such as PETG, PP, ABS, etc. Does this new trend mean the end of spool? What new players will appear in the additive manufacturing industry betting on this technology? Only the future will give the answer.