Clogging due to leftover filament that hardens and sticks to the nozzle is one of the most common issues in 3D printing, specifically if you regularly cycle between different filament types with distinct melting points.
Fortunately, a technique called cold pulling, where we can use another piece of filament to gather all the debris in the nozzle, allows us to resolve most clogging issues without the requirement of disassembling the nozzle and cleaning it.
Today, we will be discovering whether it’s possible to perform the process of cold pulling to unclog a 3D printer’s nozzle with PETG filament specifically, as PETG is usually the only filament type that many 3D printing enthusiasts have access to starting out.
So, can you perform a cold pull with PETG filament?
While it’s not the best filament to perform a cold pull with, especially for removing filaments with higher melting points, it’s entirely possible to go through a successful cold pull with PETG filament as long as you are careful enough not to snap it.
Next up, we will further discuss if it’s possible to perform a cold pull with PETG filament, take a quick look at how to conduct a potential cold pull process with PETG, and find out how to remove excess PETG off the nozzle through cold pulling.
Can You Perform a Cold Pull with PETG Filament?
Since cold pulling is a process where success isn’t guaranteed, being aware of the nuances that make this process work as optimally as possible, such as using the right filament type, is highly significant.
Performing a cold pull with PETG filament is indeed possible, just as it is with any other type of filament. Although cold pulling with PETG may require more effort and care than a filament that is more suited for the job, you can succeed with it if it’s your only option.
The main drawback of cold pulling with PETG filament is its proneness to bend and eventually break off during the process if you aren’t careful, which will cause the cold pull to fail and create more issues as you will have to deal with the broken-off PETG in your extruder.
While not entirely a drawback, another reason that makes PETG not the first choice for cold pulling is its melting temperature being pretty close to most other standard filaments, which makes it impossible to soften the filament residue in the nozzle to make it easier for it to stick to the PETG.
How to Perform a Cold Pull with PETG Filament?
Since the variables for an optimal cold pull process slightly differ depending on the filament you use, it’s vital to perform the necessary adjustments for the process to succeed without issues such as filament breakage.
Here is a step-by-step guide you can use to perform a successful cold pull with PETG filament:
- Remove the filament you have been printing with, and disconnect the Bowden tube if your printer has a Bowden extruder.
- Start heating the hotend to the printing temperature of the PETG you will be using for the cold pull, and wait for it to reach the temperature.
- Grab a piece of PETG long enough to push through the extruder without letting go, and slowly push it through until you can see it come out of the nozzle.
- Cool the hotend down to room temperature, and keep gently pushing the PETG down during the process. At this point, the PETG should be warm enough to take the shape of the nozzle as you push down but not warm enough for it to liquefy and come out of the nozzle.
- Heat the hotend to slightly above the recommended bed temperature of the PETG you’re using, and pull the entire PETG out of the extruder slowly and steadily in an upward motion with the help of pliers once the temperature is reached.
Pulling the filament slowly and steadily is the most vital part of the cold pulling process, as applying excessive force to the filament will most likely cause it to break off inside the extruder and cause the cold pull to fail.
Upon success, the PETG should come out of the extruder in one piece, with all the residue clogging the nozzle stuck to it.
How to Cold Pull PETG off the 3D Printer Nozzle?
The material you’re cold pulling off the nozzle is just as significant as the material you’re using to conduct the cold pulling process, primarily due to the fact that each material has a different melting temperature, which is a vital variable for a successful cold pull.
To cold pull PETG residue out of the clogged nozzle, we highly recommend using a filament that requires a higher printing temperature than the PETG you have used. Doing so will allow the PETG in the nozzle to melt in the process, making the residue more likely to stick to the cold pull filament as you pull it out.
While this is not a complete necessity, it will make your life easier and save you from repeating the cold pull process a few times until you get all the residue out of the nozzle.
Which Filament Works Best for the Cold Pull Process?
Considering that each filament has a unique set of properties, such as distinct flexibilities and melting temperatures, it makes sense that some filament types work better than others for the cold pulling process.
We can consider nylon filament the best option for a cold pull due to two reasons which are its flexibility, making it unlikely to break the filament during the process, and its high melting point, allowing us to melt the residue in the nozzle.
As a result, it’s often a good idea to keep some nylon filament handy even if you aren’t planning on printing with it, especially if you have to go through the cold pull process due to the clogging of the nozzle.
The skill to clean a 3D printer’s nozzle by cold pulling is, without a doubt, something that will come in extremely handy for all 3D printing enthusiasts, especially those who switch between different filament types frequently.
To quickly recap, it’s technically possible to perform a cold pull with any filament, and PETG is no exception to this rule. On the other hand, as PETG is not the best choice to perform a cold pull with either, you will definitely need to be more careful not to break the filament.
As a rule of thumb, filaments that are more flexible and have higher melting points are the best options for a cold pull, as the flexibility prevents the filament from snapping, and the higher melting point allows it to withstand the heat that melts the residue clogging the nozzle.