"The Special One" - Directly from Japan
Sometimes surfing internet for bit more technical aspects of 3d printing guides toward unexpected results. For me it was finding Nature3D website with their intriguing and unique filaments. By unique i mean that i could not find anybody who makes anything similar - their most "common filament" is high temperature PLA which withstands temperatures way above 100C and sands like no other PLA. As there was an possibility to receive sample of this filament i've requested one - some time later (extra time due to mainly customs...) my sample arrived.
When I started printing it became obvious that this filament is not ordinary PLA. For starter its less forgiving when it comes to Bed leveling and printing surface condition. Personally I print on glass with layer of Glue (Scotch glue stick) which over time absorbs moisture and requires re-applying usually every few days - LFY3M refused to adhere to bed which i could class as "still usable". After applying fresh layer of glue all issues with adhesion disappeared. One thing worth noting is that initial adhesion issues were not related to material warping like it is with for example ABS its more related in my opinion to material composition (mineral filler).
Another observation was print colour and surface feel - its hard to capture on camera, but i would place it between matt and silk. It doesn't have typical thermoplastic shine, more like something between very fine unglazed ceramic and marble.
If accounting for above it would be good but not "special" filament. Fun starts when you try to sand this filament. PLA is generally treated as very hard to sand efficiently due to very low glass temperature which causes material to soften during sanding and produce stringy and messy surface texture when sanded. Generally it requires very careful sanding ideally wet sanding. Usually only effective method to achieve smooth pla print surface is using fillers and sanding them. That is until you try sanding this filament - it sands like fine filler, no stringing, smooth to touch texture even with relatively coarse sandpaper (120 grit).
I've tried also using bit more "brute force" - powered up my sander - few moment and surface of print got to pictured state - bit more sanding and nobody would be able to recognize that it has been printed on FDM printer.
All above features of this filament are only bonuses to its main Feature - resistance to heat. PLA resin in normal printed state starts to soften around 60C making it not usable for anything which requires usability in hot environment. PLA's low temperature resistance means that usability of this material is heavily restricted. leaving it in car during summer day even in UK will give you nice modern molten sculpture from your freshly printed phone holder. Your new stencil for making fancy coffee won't survive contact with your coffee not to mention session in dishwasher.
LFY3M can be Annealed giving it resistance to high temperatures - throw it into oven @110C for 20 minutes and your print thanks to magic of internal resin crystallization becomes much more resistant to higher temperatures. Resulting prints will survive boiling water or session in dishwasher without issues. High temperature PLA is not something new. Proto Pasta has own line of HTPLA which also can be heat treated, but those don't have same mineral filler which give LFY3M its ease of post processing, especially ease of sanding.
Price wise its fortunately placed very reasonably for what you get - approx 20GBP for 0.25kg of filament placing it same price bracket as other advanced PLA filaments.
Unfortunately not everything about this filament is ideal. For starters it has bit restricted choice of colours, and by that i mean there is at the point of writing this article only one available - White. It is also bit more brittle than typical PLA - thin wall prints are not its speciality. You will want at least 1mm wall thickness to get mechanical strength, although if you are printing for thermal resistance 100% infill is recommended. Another issue is availability outside Japan - you can only buy it currently directly from nature3d which will involve dealing with customs and international shipping charges.
Now i need to find a way to get more of Nature3d filaments and maybe convince some local distributors to stock it.
You can find more details about Nature3D filaments on their website - nature3d.net
If you want to review their filament - check this: http://nature3d.net/service/freefilament_en.html