Hours are spent in researching the 3D printer market to determine which of the dozens of Fused Deposition Modeling (FDM) 3D printers will meet the need of the consumer. However, relatively little time is spent determining which filament will produce the desired results. For all intents and purposes, the filament is the life-blood of any 3D printed project and great consideration should be given to the quality of the filament used.
There are at least two factors that determine the quality of 3D printing filament: the roundness and the consistency of the diameter of the filament. When the filament becomes more oval than round, extrusion of the filament may cease. When the diameter of the filament thins, the tension mechanism is unable to grasp the filament and then push it through the head of the nozzle. If the diameter should become too thick, the extruder motor may not be able to push the filament through or the nozzle may be unable to handle the excess and the outcome is a clogged nozzle. Also, a diameter increase can affect the extruder gear that may then shred the plastic before it gets to the extruder. A 2% difference in the diameter of the filament will result in a 4% difference in the printed width.
Another characteristic to look for in filament is the size of the hub of the spool on which the filament is wound. Spools come with different center diameters. Tightly wound filament is more difficult for the 3D printer to pull from the spool. This can cause the extruder gear to slip and/or strip the filament. The end result is a failed print. Also, when the filament cannot be pulled from the spool because it is wound on a small hub, there is considerable waste of filament. A hub that is 100 mm is considered to be of adequate size to avoid potential waste.
A good indicator that a 3D printing company offers quality filament is when vital information is given in the description of the filament. This information should include the filament diameter, roundness and the hub diameter. BootsIndustries.com states that the gold standard for 3D printing filament tolerance is 0.05 or lower. However, after researching several companies that are known for quality filament such as SainSmart, Octave and Afinia, the standard appears to be >0.10 mm.
Octave offers the following information on their spools of filament (see image).
Finally, the way the filament is packaged and stored is a very important consideration. Both ABS and PLA filament will absorb the moisture in the air to which it is exposed. Once the filament is heated during the printing process, the moisture in the filament will “explode” and the quality of the filament will be greatly diminished. The end result is a poor quality print. Therefore, the filament should be sent to you in a vacuum packed bag or at the very least, a sealed bag with a desiccant pack for absorbing the moisture.
Note: Discard the desiccant pack if it is hard. To keep the moisture from the filament while it is stored, place it in an enclosed container with rice. The rice will do the work of the desiccant pack and absorb the moisture.
Purchase filament from a company that has experience with 3D printing. Avoid resellers who do not test the product or give vital information.
Purchase filament that has consistent roundness and the tolerance is stated.
Purchase filament that comes on a large diameter spool. An inner spool diameter of 100 mm is recommended.
Purchase filament that comes shrink wrapped or sealed with a desiccant pack. Store in an enclosed container with a rice to absorb the moisture.