I'm looking into LW-PLA. It looks like plastic, but feels more like cardboard. This is one example of temperature activated materials, its volume changes depending on print temperature.
At 190C it's close to normal PLA, but after that it starts to foam. At 250C it behaves like insulation foams, expanding up to 2.5 times the volume. It makes parts that have PLA's charasteristics, except it's incredibly light. This benchy was printed with 45% flow and it feels unreal to hold as it weights absolutely nothing.
This material is typically used in weight sensitive applications, like RC planes and likes.
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