FDM 3D printing is the most widely used 3D printing technology, and basically all FDM 3D printers use PLA and ABS wires as printing materials. However, this situation has changed. Some FDM 3D printers begin to use plastic particles as printing materials.
For a long time, plastic particles are mainly used for injection molding, including wire rods used for 3D printing. When 3D printing with plastic particles, the extrusion method is slightly different from the wire. The plastic particles are added into a funnel shaped container and enter the melting zone at a certain speed. The plastic particles are hot melted into paste, and then extruded onto the printing platform through the nozzle.

Compared with wire, printing with plastic particles has the following advantages:
1. Lower material cost
As the wire is made of plastic particles, it saves one step to use plastic particles directly, and the cost of particles is about 65% to 90% of the wire;
2. Faster printing speed
Because the particle bin can be preheated in advance, the throughput can reach 100 times of the wire rod, and the extrusion speed can reach 200 times.
3. Better mechanical performance
The wire made of plastic particles requires heating, and some properties will be lost. The direct thermal melting of plastic particles avoids this problem.
4. Recycling
Not only 3D printed plastic parts, but also other plastic products can be used as printing materials after being cleaned and crushed into granules.

Compared with wire, plastic particles also have some disadvantages:
1. The printing process is irreversible. When printing with wire, it can be paused or canceled at any time. When printing with particles, it has no such flexibility and needs to be printed at one time;
2. The surface is rougher, and the stability is not as good as that of wire rod. Voids, warpage and other problems may be encountered.
3. The fineness is relatively low. The wire can accurately control the extrusion speed to obtain the corresponding fineness. The control of particle printing flow rate is not as accurate as that of wire.

Based on the above comparison and their advantages and disadvantages, granular materials are suitable for printing large plastic parts, such as various furniture and ship parts. The wire material is stable in printing, and suitable for printing small plastic parts and plastic parts with certain accuracy requirements.