Okay, ive tried searching this topic and i have found some stuff but nothing specifically like what im searching for.
So regular white and black PLA, only ever minor issues which were fixed with retraction settings. Silk though, oh gosh!!!
Both this gold from Hatchbox and a duel color from Elegoo seem to “blob” coming out of the extruder. It looks like it blobs out, and then flows(ive watched it as i load the filament).
You can almost see the flow move down the string as it evens out. Clearly this makes the prints stringy and nasty.
I tried the range out temps and nothing changes. Ive done everything between 190-230(yes i know 190 is far to low)
Changed the hot end out just in case, played with retraction distance and speeds, flow rates, temps, speeds, popped it in my garage oven to see if it was a moisture issue. Nothing seems to help.
I changed back to white just to test and the white extruding was beautiful. As you can see in the picture, the white comes out fine and even. The gold was thick and only evened out after it fully extruded.
This is called “die swell.” It is caused by pressure inside the nozzle, and is primarily an indicator that the filament is being over-extruded for it’s current parameters (too much, too fast, too cold, or any combination thereof). All filaments have a certain degree of die swell, and usually it is unnoticeable, but some have more than others (clearly). It is nothing to worry about during the loading process, but it is one of the reasons you need to tune your printer and slicer settings for each individual filament when printing with it. With proper tuning, this won’t be a problem. The best process for print tuning can be found here, at the bottom of the first post:
Also, keep in mind that silk PLA filaments are more prone to moisture absorption than regular PLA, so you need to make sure it has been dried (one of the listed steps in the print tuning).
Silk filaments can be a bit picky. The polymer mix used to give them their sheen makes them a bit thicker and more viscous. During printing, with how thick it is, a fast retract can usually pull the hot melted end off the filament, leaving it to dribble by gravity. The better solution is to reduce retraction speed and distance, basically just enough to relieve the pressure.
Silk filaments also like to run a bit hotter, I found 220 a good spot for silks I’ve used. Also, during a purge or feed like loading, the thickness of the polymer makes it draw in and thicken, during actual printing, however, since the filament is being stuck down to another layer, it’s usually not a problem.
Final note to keep in mind with the shiny mixture is layer adhesion will be poor compared to normal PLA. Silks are great for making pretty things, but the weak layer adhesion makes it useless for functional prints.
