How to identify High-Quality filament for 3D printing?

Nowadays, there are many filament brands for 3D printers, and it can be difficult to choose one of them. At first, it’s easy to think that just by choosing the type of plastic (PLA, PETG, ABS, etc.), the color and the diameter of the filament would be enough. However, experience (and sometimes unsuccessful prints) shows you that this is not the case.

Even when we already have our filament spool in our hands, it can be difficult to identify if the filament is in good condition or if the quality of the pellet is good or bad. To the untrained eye, it might appear that as long as it melts and sticks to the print bed, the plastic will serve its purpose; but by finding inconsistencies in printed parts or failed prints, you may realize that cheap filament becomes expensive. If filament spools aren’t chosen correctly, you will have an unforeseen loss of electricity, time, and raw material.

Here is a list of items to keep in mind when making your filament purchases:

• Be aware of filament diameter tolerance: One of the most common metrics that filament distributors list is their tolerance. The most common and the cheapest filament spools have a tolerance of +/- 0.05 mm. If you can afford to buy one with a lower tolerance, you should.

• Check the tolerance of the filament: After you have purchased your filament spool, it is recommended to occasionally inspect that the tolerance is within the value specified by the manufacturer or distributor.

• Check the vacuum seal of the spool: If upon receiving the spool, you see that the bag where it's packed is not vacuum sealed, most likely the filament has absorbed a good amount of moisture and it will affect the print quality of the pieces. You can check if the seller issues refunds or offers any kind of guarantee.

• Listen to the extrusion flow: If when loading the filament in the printer, you start hearing small bubbles popping, it means that your filament has absorbed moisture. In this case, it is recommended to use a dehydrator to reduce the water content of the filament. Be careful not to exceed the glass transition temperature of the type of filament you are drying. Set the dehydrator at least 20ºC below this temperature.

• Identify variations in color: This parameter may not be as relevant for everyone. But, sometimes, for the client, the homogeneity in the color of its plastic parts is of great interest. However, realizing if a brand has good consistency in the color of its filaments is something that is difficult to identify a priori. This is something that you can find from other people's reviews or empirically.

• Bend the filament: Before loading the filament into the printer, bend the filament and identify if it is more brittle than normal. If it is, it is very likely that it has been exposed for a long time to UV sunlight, resulting in the degradation of the polymer. In this case, you can discard the outermost layers of the spool and continue printing with the innermost layers, where there will be filament that has not received sunlight.

• Look for signs of stringing: There are some types of filaments that, due to their properties, tend to leave many small filament threads (stringing). However, if the type of filament you are using is not one that normally generates stringing, it is likely that your filament has absorbed moisture and needs to be dried.

If you took these recommendations into account and bought a good spool of filament, do not forget to store the spools in dry places where UV light isn’t present. Preferably, if you can store them inside a resealable vacuum bag, the better. In our experience, we have found that the PolyMaker brand offers very good value for money spools of filament. If you are interested in buying filament that will not let you down and if you liked the content of this blog, consider purchasing filament on the Quality 3D Prints website.