Esun is one example, who makes special cleaning filament, but there are other brands and this is all material used from the injection molding industry.
Another symptom is when folks use wire or needles or drills to push into the nozzle from the bottom, this lifts the check ball and then the nozzle flows for a bit, and then jams again. The idea behind the cold pull is to trap this dirt or foreign substance in melted filament and pull it out from the top side with the filament. This is where again, special cleaning filament has properties that may be better for this than just your normal filament. Cleaning filament is a wide temp range plastic with a relatively low melting point, but wide range of heat before it sustains damage. This means you can use it for colder filament like PVA cleaning, and also with ABS and other higher temp materials without having multiple special cleaning filament. Another good thing is that this cleaning filament has dire swell. This means the filament wants to expands when heated and melted. This helps wipe the walls and nooks and mating joint where the nozzle mates to the thermal barrier tube. Split for length..
As a suggestion, using a specific cleaning filament can help during a cold pull. The reason thought for this kind of jam is that some particle that will not flow through the nozzle due to size and the fact it does not melt (could be dirt, dust, hair, contamination in the filament itself or stuff that just sticks to the filament and is pulled into the hotend over time) forms a “check ball” that under certain conditions will push down into the cone shape of the internal nozzle and basically block it. Since there can be laminar flow of hot molten plastic, this can float this check ball at some times, and the nozzle flows normally, then other times you get a rock solid jam. Comment split for length…
Once they have, you'll be able to view a graph of their reputation gained over time.
Here's a preview of what the graph will look like:
No reputation gained yet.