Nice informational video! As I saw over the time, keeping your filament with dessicant in a closed box does a great job of keeping the moisture out of the filament. Also, the vacuum chamber would help the boiling temperature to drop down and the water would easily evaporate. But keep in mind, the vacuum pump may be affected by the water you get out of several spools :) Keep up the good work!
Many thanks! Yes a couple folks wrote about the water, in the bigger scope of things I am not sure how water it would take to affect it as the yield is only around a gram so t point yes. However I am going to design an in-line descant chamber and see how that works...
I think the reason that water won’t leave the desiccant is because the water in the desiccant has a lower activity (similar to concentration) compared to pure water and therefore has a lower vapour pressure. You need a radiant heat source to pass into the vacuum, try a heat lamp. Please never apologize for being geeky.
LOL! "Please never apologize for being geeky" Thanks for the positive support :-) You could have a point there " pure water" and some thing I have not and some thing I will look into!
Oh wow. I'm relatively new to 3D printing, but because I use it as part of my production process, I already own a vacuum pump / chamber. Thank you for being the bearer of very good news to yours truly. If a radiant heat source is required for the chamber, a reptile heating mat is a very inexpensive way of achieving it.
I work in HVAC, very large scale hvac to be precise, even with large, very powerful vacuum pumps, you will never achieve 30 in. HG, that is absolute vacuum, if you can reach 29.5-29.8 that’s as close to perfect vacuum as can be achieved. Just food for thought
Based on ur premise... why not ha an air tight container to hold the desiccate setup between the pump and chamber. Then have another similar container of desiccate on the incoming air bleed valve so the air coming back in has a minimal amount of water from the ambient air. My current ambient air is 38 percent moisture. The thing hats confusing is ... it’s pretty difficult to measure moisture content of the filament.
The idea here is the chamber is a dryer whereas a "dry box" would be used to keep it dry once it was dried. If you place hydrated filament in a dry box with desiccate alone it won't have much affect...
Just for fun you can try pulling a vacuum on water until it freezes in mid boil. It would be interesting to see if that vacuum pump can do it, the vacuum pumps I've used to do this were much larger.
Sorry no can do as the water boils it gives up heat and therefore takes more vacuum. I am assuming to race that "down" it would take a molecule vacuum pump as I don't think even a two stage could do this... But it would be neat to do for sure!
www.amazon.com/StonyLab-Glass-Vacuum-Serrated-Length/dp/B07CGQMVXL You submerge that contraption into a cold bath (dry ice/acetone is good for -70C), then connect it inline between your pump and the chamber or whatever else you are pumping on. Keeps harmful vapors out of your pump/oil.
@@DIY3DTECHcom Basically the line to the pump runs through the cold trap which provides a region of cold or super-cold which causes any water or solvent vapors to condense and freeze before being pulled through the vacuum pump. I'd think it would be useful for resin degassing as well to prevent the resin solvents from degrading the pump oil. Here's an image link with the concept. en.m.wikipedia.org/wiki/Cold_trap#/media/File%3ACold_Trap.PNG The container could just be a small cooler with dry ice and isopropyl alcohol. The trap could be made with 2 different sized copper pipes soldered together with a fitting to drain the trap on the bottom.
Wow that seems like a lot of complexity and not something the average Joe would do. I wonder if there is there another way as I was thinking about designing an in-line desiccant chamber. Your thoughts?
Yep a dessicant tube or the like will work for water, but not VOCs obviously. I plan on also using mine to reclaim IPA from post processing of resin prints. AFAIK a cold trap is really the only way to go for that.
Very Nice video and explain. I had made something very similar, but home made recipient. I'm pulling vacuum with my diesel car brake booster vacuum pump,but only but I only reach about 50 or 55 cm of mercury that are like 20 inches of mercury you think is enough for dry my nylon with carbon fiber filament? Another question: you says at the video 70° or 80° but Farengheit? are you sure? or Celcius?. Could you tell me complete cycle of temperature and vacuum made for dry Nylons filaments? Thank you very much for your videos. Are very good.
Thanks and keep in mind you don't need a lot heat in a vacuum as the issue is as the water leaves the plastic it takes with it heat and in vacuum there is small spread in the vacuum to boiling point. So the vacuum is always chasing the heat so a little warmth goes a long way...
@@DIY3DTECHcom I understand. The problem that I have is that even after giving it 3 or 4 hours of 60° to 75° celcius of temperature and then applying it around 3 or 4 minutes of 20 inches of mercury of vacuum I still hear it burst and boil the nylon filament with carbon when it is extruded by the nozzle and the finish of printed part is not goot yet. Thank you for yor faste response. You are very friendly. Greetings!
The vacuum at which water boils is dependent upon the barometric pressure and your altitude. And you need a desiccant bag to help your pump oil from getting fragged and help the pump work less hard.
Yes sort of "vacuum at which water boils is dependent upon the barometric pressure and your altitude" because if your at sea level there will more "pressure" to remove then say if your at the top of a mountain. The sort of is can't see "huge" difference unless you go from say San Diego to Denver. However would like to understand better your thoughts on the desiccant usage and a " fragged" up pump as I am no vacuum pump expert :-)
I'm a chemist by training and am fairly sure you need desiccant. Sure enough that I ordered a gallon of the chromium-dyed silica gel beads along with my chamber. When the partial pressure of water vapor inside the vessel reaches the vapor pressure of water at the temperature of the liquid, vaporization reaches equilibrium. This means vapor gets trapped back onto the surface of the liquid at the same rate as it evaporates. In a closed system you simply won't be able to release more water than the vessel holds at the given vapor pressure. Therefore if you want to liberate more water from the cup (or your filament, etc), you have to give the water vapor another place to go, or the vacuum chamber can't do any more net work for you. This where the silica gel comes into play. As far as the silica gel also releasing its water in a vacuum - it will, but only when it reaches the analogous equilibrium value. If you start with a good amount of fresh/dry desiccant you should be able to trap a fair bit of water vapor before reaching that equilibrium. The experiment I see is to do what you did here, twice, at the same temperature, but with/without desiccant. Then weigh both of the water vessels, as well as the desiccant, before/after. You may need to leave it at vacuum for awhile, to give the vapor time to travel from the cup to the desiccant. You also need to account for the fact that if you leave the pump on, vapor goes all the way to the pump and ends up trapped in the oil. That's not good for the pump long-term. Best practice would be to use a cold trap. That also gives the vapor another place to go. And since the trap is cold, the liquid condensate that forms there will have a much lower vapor pressure than the other things you are pumping on.
Jarrod, well the thing I can tell you is I am NOT a chemist however always want to play one on TV! However as an amature hack I am coming around to your thinking here "sure you need desiccant"! I also found you note VERY insightful to say the least and will use it as the basis for another video on the topic as this is explained very well! I totally get the part " In a closed system you simply won't be able to release more water than the vessel holds at the given vapor pressure" so the desiccant would increase the systems ability to do this. However one of the things in my test is if ran the pump for 7 min ro 15 mins there was really no difference. Why? Now if full disclose the scale you could read full grams so there might of been a fractional gram which was not measure however it was clear the function was not linear...
Yes there are things about this system I still don't fully understand. For example what the heck does the pump really do once the chamber is evacuated? I suspect not much, and that might help explain your non-linearity. The pump moves a good bit of volume at high pressure - moving away water vapor - but then almost nothing once the vessel is pumped down. This is another way to look at how desiccant might help you out. You need some sort of sink to move the water vapor out of the chamber once it gets liberated from whatever you are trying to dehydrate. The pump itself probably is not going to be all that effective as a sink, and in any case you don't want that because water in your pump is not great (which is why you are getting asked about using a cold trap - think of it as the condenser in a still, converting vapors back into liquid form before reaching your pump). My intent is to place filament + dessicant into the chamber, evacuate it, shut the valves, unhook the pump and power it off. Then let the vacuum and desiccant do all the work. The real unknown to me is whether vacuum alone is really enough to get the water out of the filament. No idea. Heat may be required as you alluded to here. I have an old, crackling roll of clear PLA sitting in my chamber for the past 24h, at about -29in Hg, with a little jar of the blue beads. I'll give it a few more days and see if it prints any better.
The piece I am unclear about is the movement of the very small amount of remaining water vapor. As without air how does it move? I realize it can sort of move on its own, however would think this would be very limited as the effluent would be very small especially with the pump turned off . In a high vacuum systems they have crazy efficient molecular pump (basically like an inverted jet engine) which create a deep draw.
@@DIY3DTECHcom The molecules are bouncing around, off the walls of the chamber. Maximizing the surface area of the desiccant should help with that. I do worry that these little $60 pumps don't pull a deep enough vacuum to reverse an already-contaminated roll of filament. We'll see, I guess. If not, I'm thinking the way to go will be to drive off the water in an oven and immediately transfer the filament to the vacuum chamber to cool down. In any case this is a superior way to store partially used rolls.
I use a setup like this all the time with a hot plate to remove impurities in butane hash oil (dabs). I use this boiling point calculator (trimen.pl/witek/calculators/wrzenie.htmlo) to get the boiling point on things like meta-benzine and hydro-carbons. I have to use tiles and china plates to transfer the heat because you're right, no air no heat transfer. I also 3D print and I'm in Hawaii, with high humidity 24/7 year round. The Low humidity point is like 57%. The filament, yes even the PETG sucks the moisture up fast. A good spool of PETG left loaded on the printer lasts about a 12 days. So I saw your video and tried it out. 4 spools at -29.6 or so inches/HG for 4 days. I would hook the chamber to the pump for 5 minutes each day. No heat. 1 spool of PETG and 3 spools of PLA +. I pulled the first spool of PLA + out today. Printed a Temperature Tower (www.thingiverse.com/thing:2729076) and boy oh boy did the vacuum change the filament. This spool printed at 215 degrees C when I first got it. It printed well, pretty nice stuff. Now I can't even get it out of the nozzle at anything below 220. It printed best at 255 degrees with 25% fan. I will try the other spools soon and keep you updated. I don't even know what to think now.
Thanks for sharing this as this fascinating, please do let me know how things progress. Also I am of the opinion now that heating the filament first before placing in the vacuum is the best way to go...
Nice informational video!
As I saw over the time, keeping your filament with dessicant in a closed box does a great job of keeping the moisture out of the filament. Also, the vacuum chamber would help the boiling temperature to drop down and the water would easily evaporate. But keep in mind, the vacuum pump may be affected by the water you get out of several spools :)
Keep up the good work!
Many thanks! Yes a couple folks wrote about the water, in the bigger scope of things I am not sure how water it would take to affect it as the yield is only around a gram so t point yes. However I am going to design an in-line descant chamber and see how that works...
Lots of good info, thanks for doing this.
Many thanks!
I think the reason that water won’t leave the desiccant is because the water in the desiccant has a lower activity (similar to concentration) compared to pure water and therefore has a lower vapour pressure. You need a radiant heat source to pass into the vacuum, try a heat lamp. Please never apologize for being geeky.
LOL! "Please never apologize for being geeky" Thanks for the positive support :-) You could have a point there " pure water" and some thing I have not and some thing I will look into!
Oh wow. I'm relatively new to 3D printing, but because I use it as part of my production process, I already own a vacuum pump / chamber. Thank you for being the bearer of very good news to yours truly. If a radiant heat source is required for the chamber, a reptile heating mat is a very inexpensive way of achieving it.
I work in HVAC, very large scale hvac to be precise, even with large, very powerful vacuum pumps, you will never achieve 30 in. HG, that is absolute vacuum, if you can reach 29.5-29.8 that’s as close to perfect vacuum as can be achieved. Just food for thought
Would be interesting trying this with a dual stage vacuum pump to se if that would improve!?
So what happened? No follow up with filament drying results? Would sure like to hear whether or not you had any success before I go down this route.
Does work and believe adding desiccant helps as it gives the "water" a place to go in the semi vacuum.
DIY3DTECH.com excellent thanks. More effective than oven drying?
Based on ur premise... why not ha an air tight container to hold the desiccate setup between the pump and chamber. Then have another similar container of desiccate on the incoming air bleed valve so the air coming back in has a minimal amount of water from the ambient air. My current ambient air is 38 percent moisture. The thing hats confusing is ... it’s pretty difficult to measure moisture content of the filament.
The idea here is the chamber is a dryer whereas a "dry box" would be used to keep it dry once it was dried. If you place hydrated filament in a dry box with desiccate alone it won't have much affect...
You could warm the spool of filament first say 3 hours to get it (Nylon 65C) all through warm and then put it into chamber.
While at first I was skeptical of value in doing so (pre-heating) I have since come around on the point and agree especially for "deep" dehydration.
I’m curious to see how much weight is lost in the filament after being in the vacuum.
around a gram depending on filament as most filament other then nylon does soak up a bunch of water...
Just for fun you can try pulling a vacuum on water until it freezes in mid boil. It would be interesting to see if that vacuum pump can do it, the vacuum pumps I've used to do this were much larger.
Sorry no can do as the water boils it gives up heat and therefore takes more vacuum. I am assuming to race that "down" it would take a molecule vacuum pump as I don't think even a two stage could do this... But it would be neat to do for sure!
Are you using a cold trap so the water vapor doesn't contaminate the pump oil?
no I am not, please do tell more? :-)
www.amazon.com/StonyLab-Glass-Vacuum-Serrated-Length/dp/B07CGQMVXL
You submerge that contraption into a cold bath (dry ice/acetone is good for -70C), then connect it inline between your pump and the chamber or whatever else you are pumping on. Keeps harmful vapors out of your pump/oil.
@@DIY3DTECHcom Basically the line to the pump runs through the cold trap which provides a region of cold or super-cold which causes any water or solvent vapors to condense and freeze before being pulled through the vacuum pump. I'd think it would be useful for resin degassing as well to prevent the resin solvents from degrading the pump oil. Here's an image link with the concept. en.m.wikipedia.org/wiki/Cold_trap#/media/File%3ACold_Trap.PNG
The container could just be a small cooler with dry ice and isopropyl alcohol. The trap could be made with 2 different sized copper pipes soldered together with a fitting to drain the trap on the bottom.
Wow that seems like a lot of complexity and not something the average Joe would do. I wonder if there is there another way as I was thinking about designing an in-line desiccant chamber. Your thoughts?
Yep a dessicant tube or the like will work for water, but not VOCs obviously. I plan on also using mine to reclaim IPA from post processing of resin prints. AFAIK a cold trap is really the only way to go for that.
Very Nice video and explain. I had made something very similar, but home made recipient. I'm pulling vacuum with my diesel car brake booster vacuum pump,but only but I only reach about 50 or 55 cm of mercury that are like 20 inches of mercury you think is enough for dry my nylon with carbon fiber filament? Another question: you says at the video 70° or 80° but Farengheit? are you sure? or Celcius?. Could you tell me complete cycle of temperature and vacuum made for dry Nylons filaments? Thank you very much for your videos. Are very good.
Thanks and keep in mind you don't need a lot heat in a vacuum as the issue is as the water leaves the plastic it takes with it heat and in vacuum there is small spread in the vacuum to boiling point. So the vacuum is always chasing the heat so a little warmth goes a long way...
@@DIY3DTECHcom I understand. The problem that I have is that even after giving it 3 or 4 hours of 60° to 75° celcius of temperature and then applying it around 3 or 4 minutes of 20 inches of mercury of vacuum I still hear it burst and boil the nylon filament with carbon when it is extruded by the nozzle and the finish of printed part is not goot yet. Thank you for yor faste response. You are very friendly. Greetings!
The vacuum at which water boils is dependent upon the barometric pressure and your altitude.
And you need a desiccant bag to help your pump oil from getting fragged and help the pump work less hard.
Yes sort of "vacuum at which water boils is dependent upon the barometric pressure and your altitude" because if your at sea level there will more "pressure" to remove then say if your at the top of a mountain. The sort of is can't see "huge" difference unless you go from say San Diego to Denver. However would like to understand better your thoughts on the desiccant usage and a " fragged" up pump as I am no vacuum pump expert :-)
ummmm using a vacuum pump would surely change the barometric pressure inside of the vacuum chamber,,isn't that the idea of using the vacuum chamber?
I'm a chemist by training and am fairly sure you need desiccant. Sure enough that I ordered a gallon of the chromium-dyed silica gel beads along with my chamber.
When the partial pressure of water vapor inside the vessel reaches the vapor pressure of water at the temperature of the liquid, vaporization reaches equilibrium. This means vapor gets trapped back onto the surface of the liquid at the same rate as it evaporates. In a closed system you simply won't be able to release more water than the vessel holds at the given vapor pressure. Therefore if you want to liberate more water from the cup (or your filament, etc), you have to give the water vapor another place to go, or the vacuum chamber can't do any more net work for you. This where the silica gel comes into play.
As far as the silica gel also releasing its water in a vacuum - it will, but only when it reaches the analogous equilibrium value. If you start with a good amount of fresh/dry desiccant you should be able to trap a fair bit of water vapor before reaching that equilibrium.
The experiment I see is to do what you did here, twice, at the same temperature, but with/without desiccant. Then weigh both of the water vessels, as well as the desiccant, before/after. You may need to leave it at vacuum for awhile, to give the vapor time to travel from the cup to the desiccant. You also need to account for the fact that if you leave the pump on, vapor goes all the way to the pump and ends up trapped in the oil. That's not good for the pump long-term. Best practice would be to use a cold trap. That also gives the vapor another place to go. And since the trap is cold, the liquid condensate that forms there will have a much lower vapor pressure than the other things you are pumping on.
Jarrod, well the thing I can tell you is I am NOT a chemist however always want to play one on TV! However as an amature hack I am coming around to your thinking here "sure you need desiccant"! I also found you note VERY insightful to say the least and will use it as the basis for another video on the topic as this is explained very well! I totally get the part " In a closed system you simply won't be able to release more water than the vessel holds at the given vapor pressure" so the desiccant would increase the systems ability to do this. However one of the things in my test is if ran the pump for 7 min ro 15 mins there was really no difference. Why? Now if full disclose the scale you could read full grams so there might of been a fractional gram which was not measure however it was clear the function was not linear...
Yes there are things about this system I still don't fully understand. For example what the heck does the pump really do once the chamber is evacuated? I suspect not much, and that might help explain your non-linearity. The pump moves a good bit of volume at high pressure - moving away water vapor - but then almost nothing once the vessel is pumped down. This is another way to look at how desiccant might help you out. You need some sort of sink to move the water vapor out of the chamber once it gets liberated from whatever you are trying to dehydrate. The pump itself probably is not going to be all that effective as a sink, and in any case you don't want that because water in your pump is not great (which is why you are getting asked about using a cold trap - think of it as the condenser in a still, converting vapors back into liquid form before reaching your pump).
My intent is to place filament + dessicant into the chamber, evacuate it, shut the valves, unhook the pump and power it off. Then let the vacuum and desiccant do all the work. The real unknown to me is whether vacuum alone is really enough to get the water out of the filament. No idea. Heat may be required as you alluded to here. I have an old, crackling roll of clear PLA sitting in my chamber for the past 24h, at about -29in Hg, with a little jar of the blue beads. I'll give it a few more days and see if it prints any better.
The piece I am unclear about is the movement of the very small amount of remaining water vapor. As without air how does it move? I realize it can sort of move on its own, however would think this would be very limited as the effluent would be very small especially with the pump turned off . In a high vacuum systems they have crazy efficient molecular pump (basically like an inverted jet engine) which create a deep draw.
@@DIY3DTECHcom The molecules are bouncing around, off the walls of the chamber. Maximizing the surface area of the desiccant should help with that. I do worry that these little $60 pumps don't pull a deep enough vacuum to reverse an already-contaminated roll of filament. We'll see, I guess. If not, I'm thinking the way to go will be to drive off the water in an oven and immediately transfer the filament to the vacuum chamber to cool down. In any case this is a superior way to store partially used rolls.
I use a setup like this all the time with a hot plate to remove impurities in butane hash oil (dabs). I use this boiling point calculator (trimen.pl/witek/calculators/wrzenie.htmlo) to get the boiling point on things like meta-benzine and hydro-carbons. I have to use tiles and china plates to transfer the heat because you're right, no air no heat transfer.
I also 3D print and I'm in Hawaii, with high humidity 24/7 year round. The Low humidity point is like 57%. The filament, yes even the PETG sucks the moisture up fast. A good spool of PETG left loaded on the printer lasts about a 12 days.
So I saw your video and tried it out.
4 spools at -29.6 or so inches/HG for 4 days. I would hook the chamber to the pump for 5 minutes each day. No heat. 1 spool of PETG and 3 spools of PLA +.
I pulled the first spool of PLA + out today. Printed a Temperature Tower (www.thingiverse.com/thing:2729076) and boy oh boy did the vacuum change the filament.
This spool printed at 215 degrees C when I first got it. It printed well, pretty nice stuff. Now I can't even get it out of the nozzle at anything below 220. It printed best at 255 degrees with 25% fan. I will try the other spools soon and keep you updated.
I don't even know what to think now.
Thanks for sharing this as this fascinating, please do let me know how things progress. Also I am of the opinion now that heating the filament first before placing in the vacuum is the best way to go...