Filament Moisture Problems: Why Your School's Prints Keep Failing

Having trouble fixing faulty 3D printing in the lab at school? Projects that distort, break, or ooze halfway through printing are a common occurrence, and you're not the only one who experiences this annoyance. Who is the secret culprit? Filament that is wet with moisture.

Weak, brittle, and untidy prints result from most 3D printing materials absorbing atmospheric water. There is some good news, though: Proper drying and storage procedures can prevent filament (and your students' projects) from going bad. Now that you understand why prints ruined by moisture are so common, let us learn how to identify wet filament and the best strategies to correct or prevent this problem, so you can keep your class's 3D printer running smoothly all year round.

Why Filament Absorbs Moisture?

Several of the most common 3D printing materials are highly hygroscopic. This indicates that they take in atmospheric moisture. Some examples are PLA, ABS, PETG, TPU, Nylon, and PVA. Depending on the area's relative humidity, the filament can still absorb moisture, even when kept inside.

Spun out of its bag, a spool will start to soak up water in no time. It may become useless within hours or days, particularly in damp conditions. The ideal environment for this challenge is school labs, which are frequently not climate-controlled.

What Moisture Does to Filament During Printing?

Pushing wet filament into a heated end causes the water to evaporate, leaving behind steam. Within the nozzle, this steam quickly expands. It makes the plastic explode, hiss, or sputter by generating bubbles. Inconsistency occurs in the extruded filament. As a result, print flaws become apparent.

Steam damages the internal structure as well as the surface finish. Little air pockets could be present in every layer. Because of these spaces, the component becomes weaker. There are instances in which the layers fail to adhere properly. The finished product might crumble, shatter, or snap even under light pressure.

How to Spot Moisture Problems in the Classroom?

There will be obvious indicators if you're working with wet filament. You may hear popping or sizzling sounds while printing. Additionally, bubbles or steam could be visible coming out of the nozzle. Pitted, blurry, or otherwise unappealing print quality could be present.

The outer surfaces of the print may have noticeable holes, and the stringing severity increases. A web of fine filament strands connects several print locations. The strength of support structures may decrease, making them more difficult to dismantle cleanly.

Wet filament not only damages surfaces but also clogs nozzles, produces uneven extrusion, and causes layer shifts. Some students may attribute the issue to the printer or their model. The spool of filament they're using, though, is frequently where the actual problem lies.

How to Prevent Filament Moisture in School Labs?

School districts should prioritize proper storage and drying of filament if they want their 3D printing to turn out consistently well. A few basic items and practices can greatly reduce the likelihood of moisture issues.

1. Use Airtight Storage Containers

Placing filament in sealed containers is the bare minimum to keep it safe. An excellent option is transparent plastic containers with secure-fitting covers. Some even have gaskets already installed to seal off any potential moisture or air leaks. You can easily store many spools in a large container, which will take up less space on classroom shelves.

It is also helpful to have vacuum-sealed filament storage containers. These resemble standard food storage bags, but they include hand pumps and one-way air valves. They maintain a tight seal on the filament when not in use.

Purchase link: Amazon.

2. Add Desiccant Packs

Little sachets called desiccant packs can absorb excess moisture in the air. Inexpensive and effective desiccants include silica gel and clay. Drop a couple into each bag or container containing the filament. Reusable and oven-dryable desiccants are an economical choice for extended use.

Humidity indicator cards are also available for purchase. Teachers and students alike can use these to quickly check the moisture levels in various storage containers.

Purchase link: Amazon.

3. Schedule Regular Filament Drying

Over time, even spools that are well-stored can absorb some moisture. To keep the filament in good condition, dry it regularly. One inexpensive instrument that works for most filaments, such as PLA and PETG, is a standard home food dehydrator. Models with temperature settings ranging from 45 to 70 degrees Celsius will provide better control.

Purchase link: Amazon

The more sophisticated alternative is a specialized filament dryer. With a one- or two-spool capacity, these are ideal for 3D printing. Several models allow you to keep the filament dry during the print job.

Purchase link: Sunlu.

Another option is to utilize a low-temperature convection oven for occasional use. But keep an eye on the temperature so you don't ruin the spool.

Teach Students Proper Handling

You shouldn't remove filament until you're ready to use it. After printing is complete, put it back in its original packaging or seal it in its bag. Make sure your pupils know that filament is more than simply a supply—it's a delicate tool.

It might also be useful to mark the date of opening or the last drying on spools. This way, both educators and pupils are aware of the filaments that are suitable for usage and those that may require drying.

Best 3D Modeling Software for Education

There are many 3D design software available for students, but we recommend using SelfCAD. It is easy to use, and it comes with all the necessary tools that one needs to create both simple and complex 3D models. The software runs online and there is a downloadable version too so users can work both online and offline with ease. The video below shows the overview of the software.

SelfCAD also includes an in-built online slicer that lets users slice designs and generate G-code to send to the 3D printer with ease. The video below shows how to slice files in SelfCAD.

SelfCAD comes with many resources for learning, including the interactive tutorials that make it easier for users to learn how the software works. There is also a free version that you can use to test the software.

Conclusion

A common reason why 3D prints in schools fail is that the filament has absorbed moisture from the air, which is one of the simplest and most preventable issues. School districts can completely eliminate this issue by using basic storage, drying, and filament management practices.

You can help kids succeed, reduce waste, and improve print quality by keeping the filament dry. Taking this seriously will ensure that every school lab makes the most of its 3D printing program.

Frequently Asked Questions

1. How do I know if my filament has absorbed moisture?

While printing, you might hear popping or hissing coming from the nozzle. Your print can have a bumpy or uneven surface. Excessive stringing, poor layer adhesion, or fragile end components are further telltale symptoms. Your filament is probably moist if you notice any of these problems.

2. Is it still possible to use wet filament?

In most cases, drying wet filament will bring it back to its original state. Some options include a low-temperature oven, a filament dryer, or a food dehydrator. Remove any moisture by drying it at the material's specified temperature. Once it has dried, check the quality of the tiny print to make sure it is back to normal.

3. In a classroom environment, how can we best keep filament?

Seal the filament in an airtight container and add desiccant packets for storage. After each usage, make sure to reseal the spool. You can use vacuum-sealed bags or a plain plastic container with a tight cover. Putting the date of opening or last drying on each spool is also a good idea.

4. What types of filaments are most affected by moisture?

While nylon, PVA, and PETG are known to absorb the most moisture, even PLA can be damaged under damp conditions. Every type of filament is at risk in educational institutions that experience high humidity or inadequate climate control.

5. Do filament dryers really make a difference?

The best print conditions can be maintained with a filament dryer. They are useful for drying out the spool and, in many cases, printing with dry filament. This tool is fantastic for schools that print a lot, as it reduces waste and failures.