Stringing bubbles and oozing nozzles are all an indication of wet filament. I’’ve been testing quite a lot of different filaments over last couple of years and too often had the problem that materials already came moist out of the box and caused quite some trouble. So today we’’ll go into details. How a dry filament will leave you with a better print quality and improve the strength of your parts. Guten Tag everybody I’’m Stefan. And welcome to CNC Kitchen During my filament test series and also in plenty of other projects, I quite often encountered the problem that the print quality wasn’t as expected or parts failed prematurely during the tests. After taking a closer look at the samples, I noticed that the material supposedly picked up moisture from the air, causing these problems. In this video, I’’ll go into more details, which materials are susceptible to moisture intake. And how you are able to notice it. What you can do to prevent that and how you can dry out your precious filaments properly. Sanjay, from E3d contacted me a couple of weeks ago and asked me if I could show the effects of moist filament of their spoolWork’s EDGE filament to show the importance of dry filament, So I took an old roll of this material and printed the exact same GCODE with 4 different conditions: in the condition, it was after almost 2 years in my filament box dried left outside after drying for a couple of days and a special moisture conditioned state where I stored a sample in a very humid atmosphere For a couple of days. I analyzed not only printing quality, but also static strength and layer adhesion as well as the influence on impact resistance. Before we perform the real-life test, let’’s talk about which materials are even affected by moisture. Basically, all polymers can take up water. Some more than others and with different effects on your parts Most prominently, there are probably Nylon, Flexibles PC and PVA where you might already know that it’’s not a good idea to store them. Just on your shelf. But also your ABS, Asa and Co-polyester’s like Petg and E3d’s EDGE material, which we will investigate in more details, Take up water from the air, which messes up print quality and material properties. Even though I also store most of my PLA filaments directly in my office. Depending on the blend of PLA, it can be negatively affected as well. The main phenomenons that are happening with moist filament during printing is foaming and hydrolysis. If a material it wet, the stored moisture basically bubbles up and leaves you with an inconsistent extrusion result and voids in your material. Polymers, as the name already suggests, consist of lots linked smaller molecules, the monomers that give them their properties. If moist material becomes molten in your hotend hydrolysis happens, which means that the long polymer chains get cracked up by the water and therefore change the mechanical properties and, for example, causes the prints to become brittle. I deal with this problem in a way that I store all materials Besides PLA in these Ikea boxes where I added, bigger quantities of descant to the box and sealed the lid with a foam gasket. Critical materials like nylons are even directly printed out of my filament dry box because they can get bad even in a couple of hours left outside. If you want to build a filament box on your own, check out the video I made building one. Even though you’’ve just been taken your roll of filament out of the pack or thought you stored it properly. There is still a chance that it picked up moisture. So how can you judge if your filament is wet and needs to be dried? We’ll, first take a look at the nozzle when you load your material. If the molten plastic is not a nice strand of material, but has lots of bubbles on the surface. It’’s probably bad Additionally. As soon as the extruder gear stops turning, the flow of material should also stop. If material keeps oozing out of it and it shows bubbles on the surface, it’’s probably moist. Also listen closely because you can sometimes hear bubbles forming and popping. This is all caused by the water, basically boiling in the hot zone and forming steam bubbles. While you print, take a look at the outer perimeter of your part, if you see inconsistencies or bubbles, you know that something is wrong and excessive stringing is also a very good indication of moist filament. Okay, so you noticed that you precious material has been taking up some water. What can you do? Even though storing the rolls with lots of desiccant can reduce the moisture content. A bit, you won’’t be getting it totally dry. The proper way is putting it in an oven use a food dehydrator or a special filament drier for that job. They all work with the same principal by heating up the air and therefore reducing the relative humidity. When being hot, the material also releases it’s stored water much easier. I’’ve got a good electric stove in my kitchen where I can set the temperature digitally, and I know that the set temperature is around +-5 degrees accurate. If you don’’t have a similar one or don’’t want to contaminate your kitchen appliances with your filaments, then a food dehydrator is also an option. I had to slightly modify mine to make the spools fit, and I noticed that the real temperature is around 10°C lower than the set one with the knob. The temperature you set should be a little lower than the glass transition temperature with a reasonable margin of safety. For PLA, I usually use 45°C. Petg dries at 65°C and ABS or Nylons can easily withstand 80°C. As an indicator, if your drier is too hot, I let a bit of filament. Stick out of the spool. If it gets soft and deforms, I know that the temperature is too high. Also make sure that your spool is also able to withstand the heat in the oven. I, for example, have some ABS on a recycled PLA spool. So this one would only be dryable at around 45°C. The lower your temperature. The longer the drying process will take. A good 6 to 12 hours is usually sufficient. In one run a weight, the rolls in regular intervals and plotted the results in this graph. You can see that, depending on the amount of moisture, the content in the beginning reduces fast and then tends towards the really dry limit and even after 12 hours, there is still a difference measurable. Unfortunately, my kitchen scale doesn’’t have a really high resolution, so the results don’’t show the very small changes towards the end. Out of curiosity, I also measured the energy consumption of the stove and food dehydrator method. The food Dehydrator that I set to 65°C but only produced 55°C used 12kWh in 12h of Runtime, so an average of 100W. My kitchen stove was a bit harder to measure, but I estimated an average power intake of 120W at Real 65°C So both methods seem to be similarly efficient and a filament drying. Run of 12h here in Germany costs me around 30 cents, which is okay. I guess. Finally, we come to the really interesting part because I took some spoolWork’s EDGE filament that I purchased almost 2 years ago and tested it in its state. How it came out of my crude storage box, then after drying, then I left it out for 3 more days, and finally I tried to really loading it with moisture by storing a sample in a bag with a piece of wet kitchen. Towel EDGE is a co-polyester and from its properties and chemistry very comparable to other PETG filaments. I prepared a build job, which featured a 3D benchy for analyzing the print quality. Then there were two test hooks on the plate, which I used to test static strength and layer adhesion. And finally I printed 3 impact test samples. That will tell me if the material became more brittle in any state. I used exactly the same GCODE file for all 4 print jobs without any modification. The first thing, which was directly obvious, is that the print quality of the wet filament was horrible and showed lots of stringing. My untreated filament and the one I just left outside for 3 days. We’re much nicer but still showed a little bit of stringiness. The dried filament at last had an outstanding print quality with basically no artefacts or problems. The strength of the lying hooks, where the material is loaded in fiber direction was pretty much the same and doesn’’t seem to be hugely affected by moisture. Also in this static test, there wasn’t any sign of embrittlement because all hooks yielded quite a bit before failure. The standing hook showed a significant difference because the one printed with the wet filament was almost 40% weaker than the rest so layer adhesion seems to be affected. But probably only if your really store the material poorly. Taking a look at the impact strength was also very interesting because with the 3 samples each, we really have a bit of statistics and there. The moisture conditioned samples performed noticeably worse than the rest. All other ones were in the same range. So what can we learn from that? I guess the print quality difference is quite significant and might be the most important reason for keeping the filament dry, but even the mechanical properties noticeably change. Even if not thaaat much. If you store the material poorly. As I said, these results are for a PETG-like material, which is not that well known for its moisture problem and trust me with materials like Nylon or flexibles. This is ways worse. Depending on where you are living, it might be a good idea, thinking more about filament storage in a humid summer. Let me know if you’’d like to see a similar test for another material. Wow, this again became quite a bit longer than anticipated, But I still hope that I was able to show you why it is a good idea to store your expensive filaments in a dry place, and if they got wet, how you can basically revive them. If you enjoyed the video, then please don’’t. Forget to leave a like and subscribe the channel for more. If you want to support the making of these videos, then consider becoming a Patreon or check out the affiliate links below. Also don’’t. Forget to take a look at my other videos. Thanks for watching auf wiedersehen. And I hope to see you next time.