Introduction
Filament Dry box cheap and simple
Filament is the most important ingredient of the 3D printing world. The filament or plastic filament will have an effect on the quality of your 3D printed prototype, custom-engineered parts, or professional artistic models, among others. Whether you're simply creating models at home, or engineering prototypes for further testing, you want the filament in the best condition possible. Unfortunately, over time and with improper storage, filament can degrade and lead to underwhelming prints at best and brittle prints, stringing, jamming, and ultimately, failed prints at worst. Long-term storage—anything longer than a few weeks takes specialized treatment, so that you don't sacrifice the integrity of the filament material.
Filaments like PLA, ABS, PETG, and Nylon are polymers that can absorb moisture from the air, or hygroscopy. Absorbed water converted to steam during extrusion can result in defects in the final part. With proper storage conditions, we know from various sources that exposed PLA could last anywhere between a month to two years, but with proper measures, it could be much more than that.
Understanding Filament Degradation The Role of Moisture and Environment
Filament degradation is a result of environmental factors; humidity, temperature, dust, and ultraviolet (UV) light. Moisture is absorbed by hygroscopic filaments, which bond to polymer chains. When filaments are heated in the hotend of the printer, which is typically between 190-250°C, the moisture will turn to vapor and cause bubbles, which disrupts the flow of filament extrusion. Symptoms of degraded filament include popping noises, inconsistent layer quality, poor adhesion of layers and being more brittle.
Different filaments have differing levels of hygroscopy:
● PLA (Polylactic Acid): Moderately hygroscopic, but a little easier to deal with. It will absorb moisture, but not quickly and not commonly has problems from this. If it absorbs moisture for an extended period of time, it will absorb enough to become quality impaired and brittle.
● ABS (Acrylonitrile Butadiene Styrene): Highly hygroscopic; it absorbs moisture fairly quickly, and can produce warping and cracking if it absorbs enough.
● PETG (Polyethylene Terephthalate Glycol): It is similar to ABS with regards to moisture, but it is also susceptible to a UV degradation.
● Nylon: Very hygroscopic; can absorb as much as 10% of its weight in water; it’s one of the hardest materials to physically store.
● Specialty Filaments (TPU, PVA): Generally very sensitive; they require immediate storage that is dry after you open the filament.
Variability in temperature will make it worse. As a rule, storage temperature can vary from about 65 to 90°F (18 to 32°C). However, extremes can produce thermal expansion and condensation of filaments. Dust and contaminants can accumulate in nozzles. UV light from sunlight can breakdown polymers and cause yellowing and weakening.
Shelf life can vary by filament Filament that is unopened can last indefinitely, but if filament is opened, degradation begins. If you are looking to store for a long time (months to years) the goal is to minimize exposure to air, and keep relative humidity (RH) below 20%.
Basic Storage Methods Getting Started with Essentials
Basic practices are helpful for beginners or those with budgets. The fundamental practice is to eliminate moisture.
1. Original Packaging-
always store any unused filament in the bag it came in. Manufacturers like Prusa or Hatchbox vacuum-seal spools, and put desiccant packets on spools. If you leave the bag sealed, the filament will not go bad.
2. Ziplock Bags with Desiccants:
for opened spools will fit in a heavy-duty ziplock bag or mylar sack. Sealed Bags with competent desiccant packets in each section of the bag. Silica gel packets are reusable; bake them at low heat. Air has to be expelled as much as possible to create an airtight environment, or transport, when sealing the bag. Cheap and good short to medium term, but desiccants should be rehabilitated regularly.
3. Airtight Containers:
It is sufficient for half a dozen spools to use a plastic storage bin or tub. You can fit 16 spools in a 72 quart tub; maybe better for large numbers to ride around in closets, or garages. Line the bottom of the bin with desiccants and use a hygrometer strip to measure RH. Keep metal containers out of the equation- rapid changes in temperature cause metal containers to sweat or have condensation issues.
Advanced Storage Solutions Commercial Options for Optimal Protection
For users that are serious hobbyists or professionals, the equipment you obtain ensures that filaments remain perfect.
1. Filament Dry Boxes:
Source: https://kingroon.com/products/filament-dry-box-for-3d-printing
Sealed enclosures with built-in dehumidifiers or heating control mechanisms. Examples are the Sunlu Filament Dryer or the Polymaker PolyBox which both keep RH below 15% and they can also dry filament while printing. Many include hygrometers and allow you to feed filament directly to the printer via Bowden tubes which keeps filament exposure to a minimum while in use.
2. Vacuum Sealing:
Utilizes vacuum sealers to remove air from bags that contain spools of filament and desiccants. This is a great long-term storage option for filaments you rarely use since the absence of oxygen and moisture creates a safe environment. The vacuum sealed bags could last indefinitely but you should remember to vacumm seal each time you use it.
3. Dry Cabinets or Dehumidifiers:
Electronic dry cabinets, much like dry cabinets for camera gear, can quickly bring RH down using Peltier cooling or desiccant rotors. Brands like Ruggard have dry cabinets that can hold dozens of spools and keep RH at 10-20%. More frequently used options would be room dehumidifiers which can keep an entire space dry.
4. Humidity-Controlled Rooms:
Whole room dehumidifiers can be installed specifically in the workshop for drying and keeping RH at 30-40%. Very rarely will you find a customer that does this, however, if you are at the industrial scale this could be another option.
DIY Storage Hacks Cost-Effective and Customizable
If the price of commercial options is unreasonably high, DIY options can act as just as good solutions with a little bit of creative thinking.
1. Food Dehydrators:
Take a cheap food dehydrator and customize it to become a filament dryer by adding seals and a hygrometer. Only run it for short periods and only at low temperatures (less than 80*C for PLA) to maintain a dried spool - or use it during between builds.
2. PVC Pipe Storage Tube Rack:
Source: https://www.printables.com/model/126463-filament-shelf-wall
Cut PVC pipe to the length of your spools useful for storing many rolls on a shelf. You can 3D print rack mounts.
3. 3D Printed Containers:
3D print a dry box using a file, for which I've seen loads on Thingiverse. You can glue in hyrgrometers, use small bowls for desiccant holders, and make seals. For example, the RepRack system is modular and printable. You organize your spools in a rack with enough space to get to the spools easily while protecting them from moisture.
4. Desiccant regeneration station: You can create an easy oven to dry silica gel. Bake the silica gel at 120*C for 2-3 hours, and then store it in a jar with a lid.
Monitoring, Maintenance, and Best Practices
Source: https://www.thingiverse.com/thing:4727323
Storage is not a "set-it-and-forget-it" practice, so you will want to continue to accommodate it.
● Humidity: Drop in the hygrometer you use (digital hygrometers, such as Inkbird), to keep track of the RH inside the containers you are using. You want to keep your RH under 20%. You do not have to check the humidity every day with long-term storage; once a week is ideal.
● Temperature: Climate and temperature control is recommended, and always look for rooms that do not have windows or heating elements, and don't use your garage if it is a wide swing in temperature.
● Labeling and Rotation: Always label your spools with open date and material type. Use the first material first! That way, you always have fresh material ready to print with.
● Common mistakes: Don't store the material near or with chemicals, including adhesives or in direct sunlight. Don't over-dry the material because over-drying will make the filaments' structural integrity brittle. For Nylon, box it with an oil-based desiccant to avoid static.
● Dust Cover: Use filters or dust cover, it protects it being open to the air and dust particles that can clog your filament nozzle.
Reviving Wet Filament: When Prevention Fails
If filament has been wetted, It's possible to recover it with drying techniques.
1. Oven Drying: Place the filament (on a non-stick tray) in the oven at low temperature (45-60 degrees Celsius for PLA, and up to 80 degrees Celsius for ABS) for a few hours (between 4 and 6). Be careful not to let the filament melt in the oven!
2. Filament Dryers: There are devices made specially for drying filament like the Eibos Cyclopes, which heats air and then circulates it around the spool to dry it in a few hours while measuring the moisture content.
3. Using a Dehydrator: As noted, food dehydrators work great for drying filament in volume.
