What are the precautions for removing PTFE pipe
How to Remove Stuck Filament from PTFE Tube
During 3D printing, filaments may eventually get stuck in the PTFE tube. Whether it is a broken wire in the Bowden tube or a clogged filament stuck in the hot end PTFE tube, it must be processed before printing continues.
Fortunately, it is not difficult to solve this problem. Cleaning the pipe manually is usually enough to make the 3D printer run again. However, it is important to understand the best way to do this.
In the text, I will show you how to remove a stuck filament from a PTFE tube, explain the cause of the problem and what you can do to prevent it from happening again
What causes filament to get stuck in the PTFE tube?
The main reason why the filament breaks and gets stuck in the Bowden tube is the brittle filament. Some filaments (such as PLA) tend to become brittle after absorbing too much moisture from the surrounding air.
If the filament is not used for a long time, the filament has a sufficient opportunity to absorb moisture. The next time you print with it, it may become brittle and break easily and causes the filament to get stuck in hotend
. This is why it is important to store the filament properly and keep the filament dry.
As for the filament stuck in the short PTFE tube of the heater, there may be other reasons, such as thermal creep or the gap between the tube and the metal part of the heater
What can you do to prevent it?
There are a few things you can do to prevent the filament from breaking and getting stuck:
- The most important thing is to make sure that your silk stays dry without absorbing a lot of moisture from the air. So, when you don't use it for a period of time, store it in a box or sealed bag with the silicone beads indicated. This is especially important for PLA and nylon filaments because they absorb a lot of water.
- Use high-quality filament. Low-quality filaments are more likely to have inconsistent filament diameters. If a length of filament is too wide for the tube, it may get stuck.
- Another thing you can do is limit friction and contradictions on the filament. The easier it is for the filament to enter the heating device from the spool, the less likely it is to break anywhere during operation. You can do this:Use high-quality PTFE tubing, which of tight tolerances and high temperature resistance.
Optimize the path of the tube. A bend with a small radius will generate more friction than a bend with a large radius. So whenever possible, make sure that the path of the tube is not too constrained.
Make sure that the inner diameter of the PTFE tube is the correct size filament that you are using. If it is too narrow, the filament will not pass through. If it is too wide, the filament will "bend", creating additional restraint and friction.
Ensure that the filament spool can roll freely.
How to remove stuck filament from a PTFE tube – Step-by-step
Tools & Materials
Whatever you need to disassemble your extruder and gain access to the PTFE tube coupling. Usually a set of hexadecimal drivers is sufficient
For filament that is stuck outside of the hotend
If you have a broken wire stuck in a Bowden tube or other long PTFE tube, the easiest way to fix it is to remove the tube and remove it:
How to remove PTFE tube from hotend?
1.If necessary, open the bracket of the extruder to access the coupling holding the PTFE tube. This step will vary depending on the specific 3D printer you have. If you don't know how to do it, it helps to check the printer's manual/documentation.
2.Remove the collet from the Bowden coupling. This is a typical blue, red or black clip that looks a bit like a horseshoe.
3、Push the chuck down as much as possible. This causes the metal teeth of the coupling hooked into the pipe to fall off
4、Pull out the Bowden tube while still maintaining the chuck. Pushing the tube down gently at first will help. This helps to take out the metal teeth. Sometimes they get stuck
5、Do the above steps again, but this time on the other end of the tube
Clearing the stuck filament out
6、Place one end of the tube in the PTC coupling and place it in a vise. Or, you can let someone else hold the other end. It is important that the tube is straight, as this makes it easier to remove the stuck filament
7、Insert something long and thin into the tube and push out the broken filament. A simple method is to use a fresh (not brittle) filament. Alternatively, you can use a long metal rod like a thin welding rod, or my favorite guitar string. Be careful not to scratch the inside of the tube with
8、Plug the Bowden tube back into the heater.
9、Clamp the chuck back. First make sure to push down all the PTFE tubes. Then pull up the coupling ring and add the collet clamp.
10、Reconnect the components you must remove.
11、Repeat the previous steps to reconnect the other end of the tube.
For filament that is stuck inside of the hotend
One of the most common reasons for the filament to get stuck in the heat exchanger is that the PTFE tube cannot reach the heat interrupter or nozzle. This creates a gap where the filament can melt and expand and causes PTFE tube stuck in hotend. When this happens, the molten filament will cool into a ball, preventing the filament from moving further.
One way to prevent this is to use the collet clamp mentioned above. These can prevent the PTFE tube from sliding up when retracted and prevent gaps from forming.
The filament is stuck in the tube inside the heater and is difficult to remove. To solve this problem (without causing damage), it is usually necessary to turn on the heater and clear the blockage. Sometimes it is possible to pull the tube through the top, but this can cause damage to the tube because it requires a lot of force
The specific process depends on which kind of heat exchanger you are using, it is roughly like this:
1、Unscrew the nozzle partially. This loosens the thermal insulation device on the other end of the heater block.
2、Unscrew the heating block from the heat shield
3、Remove the heat protection device from the radiator. If you cannot unscrew the screw by hand, you can use two thin M6 nuts to tighten at one end. Then, you can use the inner nut of the wrench to unscrew the screw of the heat protector.
4、Push down on the ring on the coupling and push down on the PTFE. Now, the heatbreak is gone and the tube can come out through the bottom with the stuck filament.
5、Pull out the tube from the other end. You may need to use some tool to push it in from the top
6、Remove the filament from the tube. Usually, it can simply push something, like the Allen key. If it is really stuck, please see the following method
7、Reassemble the hotend. Make sure that the lamp is consistent with the heat interrupter (or nozzle, depending on the heater design) so that no molten filament escapes to unwanted places.
If the PTFE tube is damaged in any way, it is best to replace it. A damaged tube is likely to cause problems in the future
What if you can’t push the filament out?
Sometimes, the filament will get stuck in the tube and cannot be removed by hand. In this case, boiling the tube in water will help. This softens the filament inside, and then you can push it out. PTFE is not harmed by boiling water because it is resistant to higher temperatures.
This method is safer than using a heat gun or any open flame to soften the filament.
Conclusion
It is inconvenient to stick the filament on the Bowden tube or heater, but this is not the end of the world. With a little careful disassembly and cleaning, you can make your extruder restart and run in no time
When to replace the PTFE tube?
There are many material pipes that will age after they become permanent, but PTFE braided tubes are the most durable tubes among all plastic products. As long as you use it within the scope of our product data, and don’t discount it, you will be pleasantly surprised to find that it will hardly be broken. Its service life will even be longer than your printer. But sometimes the filament will be stuck on the PTFE tube during the working process of the 3D printer. In this case, you only need to remove and clean the pipe as described above.
Where buy PTFE tube
We are the original and leading manufacturer of PTFE hose and tubing over a decade of producing and R&D experience. Huizhou Besteflon Fluorine Plastic Industrial Co., Ltd not only owns the most high-quality design team and complete quality assurance system, but also is equipped with the advance automation production line with strict quality control system. Our PTFE products are sold all over the world including America, UK, Australia, South Africa,etc with our best quality and cost-effective price. If you are interested in our products, you can contact our sales staff to purchase quality tubes.
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Post time: Jan-07-2021