Does 3D printing filament expire?
Unlike food which has a specific expiration date, filament does not have a specific expiration date. However, filament can go bad based on storage conditions. The worse the conditions the quicker the material will go bad. If you notice the print quality suffering, the first thing to check is your filament.
Filaments can absorb moisture in a matter of days or even hours depending on the type of filament. So, it is important to only remove it from the seal container only when needed. Once finished, quickly store it again.
What happens when 3D printing filaments expire?
When moisture gets trapped inside the filament it can affect color, durability, and finish. Color may appear with spots or smears, the structure may lose durability and increase in brittleness due to bubbles or gaps created when the filament is heated, and the finish may look dull. Moisture also increases the vulnerability to bacteria.
Different types of filaments expire at different rates, but what is consistent between types is the negative effect moisture creates in each.
ABS filament may expire within a month of humidity exposure, while bio-plastics such as PETG and PLA may last one to two years respectively, without going bad.
It is possible to get moisture out of a 3D printer filament by putting it in the oven at a temperature right below the glass transition temperature of the plastic. Then bake it for 4-6 hours to ensure the moisture is removed.
Some signs your filament is going bad or getting old is brittleness. If it snaps easily it is deteriorating. If you hear sizzling or popping as it goes through the extruder that can be a sign. If you see steam coming out as it passes through the extruder, that can be a sign.
Water moisture is a 3D printer filament worst enemy, but even brief exposure to air can damage an entire spool. Humidity can wreak havoc on nylon and cause it to expand.
Based on this evidence, you begin to see why properly storing filament is so important. The sooner you get it stored, and the less it is outside its storage the longer the filament will last.
Can you print with old 3D filament?
Yes, you can print with old 3D filament, but it is necessary to take certain precautions before doing it. First ensure it has been properly dried. Second, be aware of the printing temperature and be careful not to print too high.
How fast does moisture break down 3D printing filament?
The time it takes for 3D printing filament to break down is different for different types of filament. For example, PLA is corn-based, while ABS is petroleum-based, therefore the PLA is more susceptible to moisture and will biodegrade. On the other hand, ABS plastic, being petroleum based will maintain its form longer in humid environments because it doesn’t absorb as quickly.
There are two sides to every story, and recent studies have suggested the corn-based filaments and other biodegradable plastics such as PLA might not break down as quickly as once thought when coming in contact with water particles. In fact, various designers state keeping PLA spools out in the open and didn’t seem to affect the quality and still printed well after several years.
The most accepted conclusion among experts on the subject is that water is enough to decompose PLA filament, but other factors such a slight, temperature, pigment, brand, processing additives, and biological activity also play an important role.
Despite the uncertainty it is still best practice to properly store 3D printing filament in sealed containers with desiccant. Doing so will certainly help the filament from breaking down because of moisture.
How long will a 3D printed object last?
The obvious question surrounding the effect of moisture on filament is how long will a printed object last. The answer is once again, it depends on the environment. Sunlight, heat and moisture are not good but once printed an object should last a long time under normal temperature and pressure conditions.
How durable are 3D printed objects?
The next obvious question is how durable are 3D printed objects. Without getting too scientific, thermoplastics are about 50-80% as strong as injection molded objects using the same material. Interestingly, 3D printed metal parts, using the same material, are stronger than casting.