Review on 🔧 Polymaker Natural Industrial Filament by Steve Cooper

I work a lot with PC and its mixes, pushing the boundaries of what can be made into a functional part with a 3D printer. I've probably tried/used PCs from about 5 different manufacturers. My general comments are: 1) Polycarbonate (PC) is the most durable and heat resistant of all materials that can be printed on consumer printers. For solid, strong and functional parts you won't find anything better. (PS: If you have a commercial printer, you can play around with other even better performing resins like Ultem, PPSU, PEEK, etc.) 2) Out of the PC products, this one is by far the best. In general, PC is difficult to process, primarily due to its tendency to run at very high temperatures and its constant tendency to warp. Polymaker really scored with this material as it is much easier to process and still retains all the strength (perhaps more) of bare PC and about 90% of the heat resistance of bare PC. Printing Tips: PC loves heat. Polymaker recommends 230-270°C which is actually an indication that they did something with this mix as a more common PC will want to print at around 300°C. I print PC-Max at 270°C and get excellent layer adhesion and surface finish, even at print speeds around 60-70mm/s. As much as he loves the high temperature of the nozzle, he seems to get a layer temperature of around 90-100°C and, more importantly, for fairly complex geometries or large parts, he likes the build chamber. I have a controlled chamber where I can get into the mid 60°C range and it works very well. I'm printing directly onto the surface of a PEI build with only a few mm of edges around the part and have no problem with it not sticking to the build surface, but PC has been known to warp and not stick to the surface, so if you can I can just don't make it stick. Try building like this or with an ABS slurry to keep it on the surface. Be careful when removing supports and the like from the PC after printing. This is a VERY hard material and the small edges will cut you fairly easily. The only downside I have is that while it has excellent HDT compared to other materials, it *doesn't* have the heat resistance of pure polycarbonate (I've tested some samples and I suspect the HDT is around 115C is < 0.5 MPa). . Also, Polymaker's supply chain seems to be a bit volatile, with items being in stock for about a month and then sold out again for a month or two. This can be a problem when you rely on functional, salable parts. In summary, PC-Max is the best PC out there. Thanks Polymaker, keep up the good work!