PLA is most common FDM 3D Printer materials and essentially all print should yield great results. Polymaker filament is a semi-crystalline plastic and is one of the most popular and easiest materials to 3D print due to its accessible and minimal printing requirements. PLA is a biodegradable(under certain conditions) and recyclable plastic and PLA filaments are available in a variety of colours options.
Minimum Extruder Temperature - 195°C (±10°C) is required (Correct temperature will vary on your printer and colours)
Heated Bed - Not required with some machines but low to medium bed temperatures are certainly beneficial! For Glass we recommenced 60°C and bit higher 70°C on PEI/Texture Sheets. (For PolyTerra we recommenced a lower bed printing temperature around 40-50°C )
Enclosure - PLA has great dimensional stability but an enclosure will protect print from drafts to reduce warping on larger prints.
Part Cooling Fan - The ability to control the cooling fan is recommended.
Feed Path and Spooling
PLA doesn't have any specific feeding path requirements. As a general tip we recommend avoiding long and complicated feeding paths that can cause bends in the filament, this can introduce drag on the filament that may result in difficulties feeding and extruding.
Changing Filament (Between PLA material)
- Unload Filament at 200-210°C and load the new filament until you previous colour is completely purged.
Changing Filament (From higher temperature filament)
- Unload the filament at recommenced printing temperature and then load filament until the previous colour/filament is completely purged.
PLA prints at a relatively low temperature, typically printing between 190°C - 220°C.
Please use Teaching Teach Temperature tower if you wish to find the best printing temperature for your application such as high detail, overhangs, bridging etc. (Temperature Tower Generator: https://teachingtechyt.github.io/calibration.html#temp).
Experiencing high wisps or stringing?
You many want to reduce your printing temperature and try calibrating your retractions settings. (Do note, if you're using a all metal hotend/direct drive extusion setup please refer to your manufacturer recommenced retraction settings)
Retraction Tuning: https://teachingtechyt.github.io/calibration.html#retraction
For small wisps, we usually recommend using a heat gun in post processing to remove them quickly (Remember not use heat gun on part over ~5-10 seconds as part will dis form under high heat.
Bad layer Adhesion or under extrusion(Rough Surface)?
If you experience bad layer adhesion, we recommenced increasing your print temperature and reducing your print speed or part cooling fan if adhesion issue pass initial layer.
Re-calibrating your e-step and filament flow is a good calibration if you are experiencing bad under extrusion.
Extruder E-step Calibration: https://teachingtechyt.github.io/calibration.html#esteps
Flow Calibration: https://teachingtechyt.github.io/calibration.html#flow
PLA can be printed without a heated bed, however a heated bed up 60°C-70°C is recommended for the best results. Success without a heated bed will depend on your printing surface, printing environment and model size. (NOTE: 70°C is max bed temperature as most PLA crystallise and cause warping issues)
PEI/Texture Sheet: 65°C
Do you need Rafts?
Generally is not requried with PLA, however for larger print raft is helpfully if you alot of draft in room and will improve bed adhesion.
Please use the included reseaable bag with desiccant (Include in all Polymaker Range) and store it away from sunlight.
PLA is a mildly hygroscopic material that will over time absorb moisture from its surrounding environment. This process typically occurs over a period of months however in high humidity environments. Using the provided reseaable bag. Polyterra or any typically any matte filament tends to be more hydroscopic due to some manufacturer additional fiber for matte look.
Printing with a dry box is not a critical requirement to print PLA (in most cases) however a dry box can be beneficial and ensure consistent printing quality and mechanical results throughout the spool or in high humidity environmental. Active heated dryer is not require but recommended if you left the PLA in open air for more than month in wet environment.
When 3D Printing it is possible to encounter filament jams or nozzle blockages, these blockages can be caused due to a variety of reasons.
Causes and Steps to Prevent Nozzle Blockage and filament jams.
In all of these cases if the filament cannot pass through the extruder, the extruder gear will continue to try push the filament and will eventually 'chew out' the filament. If you hear a clicking or clunking sound coming from the extruder, this is a good sign that the filament is jammed or will be if ignored.
- If your extruder temperature is too low during printing, the PLA filament will not flow and will have difficulty extruding.
- If the filament is softening in the hot end, the extruder will 'chew out' the filament, causing a nozzle jam.
- If there is too much friction on the filament, the extruder may have difficulties feeding the plastic. Try feeding the filament with a spool holder in different positions (above, beside, behind the printer).
- If the nozzle height is set too close to the bed, the filament will have difficulty feeding through the nozzle eventually causing a filament jam. When printing at finer layer heights (0.1 and 0.05mm) the correct nozzle height is even more important.
- If the part is warping or lifting off the bed, the part will be pushing against the nozzle limiting extrusion and material flow.
- Filled PLA materials (CF, Metal-filled, Glitter etc.) are commonly known to cause nozzle blockages. Printing with a different PLA material or cleaning and keeping some spare nozzles is recommended. (For printing these type of filament, we recommenced higher diameter 0.6mm+ with plated nozzle (https://store.dremc.com.au/collections/plated-brass-wear-resistant-nozzles).
- Nozzle Blockages can occur more commonly with finer nozzles. The majority of 3D Printers are equipped with 0.4mm nozzles, it is important when printing or experimenting with a smaller nozzle (0.2mm) to adjust printing speed and extrusion settings and DO NOT PRINT filler filament filaments (CF, Metal-filled, Glitter etc. ) with 0.4mm smaller nozzles.
- If the filament is of poor quality is oval shaped or manufactured with an inconsistent diameter, this can cause the filament to jam in the extruder. The industry standard for filament tolerance is ± 0.05 mm. If the filament is 1.75mm an acceptable diameter variance would be between 1.70 - 1.80mm. Premium and higher quality brands can offer ± 0.02 mm tolerance. If you have difficulties printing PLA with only specific brands of filament this could signify issue with their quality control or could also be related to heat creep cover in next section.
Cleaning a clog Nozzle
If the nozzle is blocked with PLA one of the most successful solutions is to feed a tougher / harder and higher temperature material (for example PC) through the extruder. In most cases, the properties of the tougher material and its higher printing temperature help to purge and remove the clogged PLA plastic. It is important when feeding the tougher material at its required printing temperature, for PC this is 250°C and to push the filament into the extruder during this process. Another option is cleaning using provided needle with nozzle heated to 230°C or perform a cold pull using below video.
What is heat creep?
Some users have difficulty printing PLA due to a problem known as heat creep. In essence this issue is caused when heat creeps up the extruder to the extruder gear and softens the filament. Rather than the gear gripping and pushing the filament through the hot end, it will chew the filament out.
Heat creep affects lower temperature materials like PLA due to their low softening temperature of 60°C and the issue is more prominent on printers designed to print high temperature materials, dual extruder printers where a section of filament sits idle for long times or cheap 3D printers with poorly designed extruders.
Solutions to preventing heat creep.
The first step is to make sure the extruder fan is ON and cooling the extruder as intended. If you finding your hotend fan to be making a noise you may need to replace fan.
If the printer is enclosed, printing with all front doors and top hatches open may help to prevent the filament from softening near the extruder gear.
This issue is also more common when printing parts models with retraction. The filament will feed past the extruder gear multiple times with each retraction, this makes it far easier for the extruder gear to ‘chew out’ the filament. You can use below tunning to calibrate the best retraction setting for your printer setup.
Retraction Tuning: https://teachingtechyt.github.io/calibration.html#retraction
Printing simple parts with little or no retraction are more likely to be successful as the filament will only be passing the gear once.
This issue can also sometimes be overcome with a different PLA material. All Polymaker PLA based materials (PolyLite™ PLA, PolyMax PLA, PolyWood™) are manufactured with an innovative Jam-Free™ technology which improves the heat stability of the PLA filament. As a result Polymakers PLA filaments exhibit a high softening temperature of more than 140 °C, so while printing, the filament will never soften in the “cold end” and can melt rapidly once entering the heating zone. It is important to note parts printed in Polymaker PLA filaments still exhibit the same heat resistance as other PLA materials
- Printing with a heated bed at 60°C can help to improve adhesion and heat up the surrounding environment, ultimately minimizing warping and improving printing consistency.
- Alternately it is important to note that printing with the bed temperature too high can also cause models to warp. If the heated bed is too hot, the PLA will crystallize when printing and will warp. For this reason we recommend never setting the heated bed above 60°C for PLA unless otherwise stated by the manufacturer.
- The most common reason for PLA parts to warp or lift during the print is due to insufficient bed adhesion or an incorrect nozzle height. If the first layer of extruded plastic is not sticking to the bed, a small amount of small residual stress will be enough to lift the part off the bed. It is important to ensure your nozzle height and bed is leveled correctly, you are using the correct printing surfaces for PLA.
- Drafts, cool air from air conditioners and low environmental temperatures in winter can cause the material to behave differently and will print with internal stress. An enclosure with a closed front door can help to maintain the right printing environment for users having difficulty with parts warping.
Poor Layer Adhesion
Causes and steps to improve poor layer adhesion.
- If the filament is under-extruding during printing there will be inconsistencies and gaps between the layer, compromising mechanical strength and layer adhesion. It is important to ensure you are printing the PLA filament at the right nozzle temperature to ensure consistent flow and to minimize drag or tension which may prevent the filament from feeding.
- Poor layer adhesion can also be caused when printing with a PLA spoiled with moisture. When the filament passes through the hot end, the moisture erupts creating bubbles in the extruded plastic, compromising the parts mechanical properties. If a spool of filament has absorbed moisture, it can be dried however it is important to store the PLA correctly and prevent this issue from occurring.
Parts difficult to remove from platform
While excellent adhesion between the bed and part is important to achieve a successful print, sometimes it can be difficult to remove models if your adhesion is too good.
Causes and steps to improve print removal experience
- Some print surfaces specifically manufactured for PLA materials are designed to maintain adhesion with the part when the bed is heated and self-release when the part is cool. Try removing the models when the heated bed is hot or cold to see what method best suits your printing surface.
- Your heated bed may be operating too hot or your nozzle temperature may be too close to the bed. You can try making slight adjustments to the heated bed temperature or nozzle height if this improves your user experience. Of course this is a fine balance as adhesion between the print and platform is important to achieve successful prints.
- While not required, in some cases with other materials, some users will use Glue stick on top of their print surface to act as a release agent for part removal.
Resources provided by: http://www.3dtechsupplies.com.au/