Novice tip about PLA

[IrvineCAGuy 0]

As a newcomer to 3D I purchased a used UM2 (now obsolete).  The previous owner upgraded it to print 1.75mm but did not do a real "upgrade" to UM2+.

After a few print jobs, the heater went out.  Speaking with the folks at fbrc8 I learned that I can do an upgrade to UM2+.  I purchase the upgrade kit and completed the upgrade in a few hours.  Great.  I found that UM2+ prints 2.85(3mm) filament, not 1.75.  The good news, the guy gave me a case (12 rolls) of 3mm filament of assorted colors.  I spent the better part of the night trying to get the base layer not to warp and roll up, and finally gave up.  Doing some research, I discovered that PLA has a shelf-life of about 6 months and must be stored in an airtight bag with desiccant to keep it from absorbing water moisture.  The rolls he gave me must have been on the shelf for a few years.  

 

In the morning I ran down to the local filament store and got a brand new roll of 3mm black PLA.  Voila - the base print is sticking to the build plate (I did use some glue) and the build it proceeding nice and clean. 

Moral: don't use old PLA.  Other moral:  If you are new to 3D printing, buy a new printer that comes with a warranty.

[geert_2 556]

I have been printing with older spools of PLA without problems. But I do store them in a sealed box with dessiccant. It is true that old PLA gets harder, stiffer and more brittle, so it may be more difficult to find and to unwind from the spool.

 

But don't throw the old spools away yet: first try drying them in an oven at 45°C for several hours, but well below its glass transition temp where it gets soft. Store in sealed boxes with dessicant.

 

And use a bonding method for improved sticking to the glass: I use my "salt method": wiping the bed with a tissue moistened with salt water prior to starting a print, greatly improves bonding of PLA. Other people use the glue stick (a thin layer, and wipe with a wet tissue afterwards to spread it), dilluted white wood glue (ca 10% in water), hairspray (spray it outside the printer, never in), 3D-LAC, and similar. Try various methods and find one that suits you best.

 

You can still find my old manual on the salt method here:

https://www.uantwerpen.be/nl/personeel/geert-keteleer/manuals/

 

[Smithy 1,141]

I think it also hardly depends on the material/brand itself and the environment conditions.

I never stored my PLA spools in sealed bags, they just lay around somewhere and some of them are nearly 3 years old and still print very fine. 

 

Only Colorfabb matte PLA got so brittle that the filament breaks when it is just hanging on the spool holder.