Closed-cell self-expanding foam (spray foam) is an incredible materials that sees widespread use in building. However one utility that we hadn’t heard of earlier than was utilizing it to fill the inner voids of 3D printed objects. As argued by [Alex] in a half-baked-research YouTube video, this foam might be very useful with ensuring that printed boats hold floating and water stays out of delicate digital bits.
It’s fairly widespread data by now that 3D printed objects from FDM printers aren’t actually watertight. Because of the approach that these printers work, there’s loads of alternative for small gaps and voids between layers to allow moisture to seep by way of. That is the place using this self-expanding foam comes into play, because it’s assured to be watertight. As well as, [Alex] additionally assessments how this impacts the energy of the print and utilizing its insulating properties.
The take a look at prints are designed with the requisite port by way of which the spray foam is injected in addition to strain aid holes. After a 24 hour curing interval the surplus foam is trimmed. Early testing confirmed that to ensure that the froth to treatment properly contained in the half, it wanted to be first flushed with water to offer the moisture mandatory for the chemical response. It’s additionally important to have enough strain aid holes, particularly for the bigger components, because the increasing foam may cause structural failure.
As for the outcomes, when it comes to waterproofing there was some water absorption, probably within the PETG half. However after 28 hours of submerging not one of the pattern cubes stuffed up with water. The samples didn’t get any stronger tensile-wise, however the compression take a look at confirmed a 25 – 70% improve in resistance to buckling, which is sort of vital.
Lastly, after tossing some ice cubes right into a plain FDM printed field and one full of foam, it took lower than six hours for the ice to soften, in comparison with the spray foam insulated field which took just below eight hours.
This appears to counsel that including a few of this self-expanding foam to your 3D printed half makes a number of sense if you wish to hold water out, add extra compressive energy, or wish to add thermal insulation past what FDM infill patterns can present.
