Polypropylene is one of the most commonly used polymers for traditional manufacturing processes such as injection molding, blow molding and thermoforming; and it is now quickly growing in popularity for 3D printed applications due to recent breakthroughs by materials companies, such as Braskem, who have launched the next generation of polypropylene filaments into the market. These revolutionary new formulations have resulted in 3D filaments, pellets, and powders that are easy to print, have low warpage, high dimensional stability, and excellent interlayer adhesion. Now that polypropylene can now be easily printed on anything from an inexpensive $300 dollar desktop printer up to industrial large format pellet and powder printers, let’s take a closer look at why you should consider polypropylene for your next additive manufacturing project.
No Drying Required
Polypropylene is a naturally non-hydroscopic material, simply meaning that polypropylene does not absorb water. This is great news for anyone who has been frustrated with 3d printing with nylon, PETG or TPU which requires proper storage and drying prior to use. You can store polypropylene on a shelf without worrying about drying or prepping the material prior to your next print job. An excellent material benefit for print farms, service bureaus, and those who only 3D print on occasion or need to print parts on demand.
Lightweight & Durable
One of the most unique benefits of polypropylene in additive manufacturing applications is its balance of lightweight and durability. With an approximate density of 0.90 g/cm^3 Polypropylene is one of the few materials that you can 3D print with that has a density of less than 1 g/cm^3 which allows for printed parts to float in water. This results in final printed parts that are up to 30% lighter than PLA and up to 20% lighter than ABS. This also means a 700gram spool of PP will print more parts than the same 700gram spool of PLA or ABS. In addition to its lightweight, polypropylene also has excellent impact strength and durability, making it the preferred choice for drone part development, electric vehicle components and aerospace designs. Specific formulations such as Braskem’s FL900PP-CF have the ability to retain up to 99% of its impact toughness even at 0 degrees Celsius.
Good Chemical Resistance
Polypropylene resins, like most polyolefin resins, are highly resistant to solvents and chemicals. This results in final printed parts that can be easily cleaned with most household cleaners and bleaches without harming the final design. It is because of this inherent performance of polypropylene that it is often the material of choice for blow molded containers that hold many of these cleaners and chemicals. This can be a key factor in material selection for designs that will be in be exposed to continuous human contact such as handles, pedals, hooks, clips, latches, etc. For additional details on the chemical resistance of polypropylene click here.
One of the additional benefits of Polypropylene is that is easily recyclable thermoplastic. It is designated by plastic recycling symbol 5. This means that it is acceptable by most curbside recycling programs, so you can easily recycle your scraps, prototypes, and old prints easily. Recycled polypropylene can then be transformed into products such as benches, brooms, brushes, auto battery cases, ice scrapers, landscape borders, bicycle racks, rakes, bins, pallets, trays.
Producers such as Braskem have also started to develop filament formulations directly from recycled plastics. Their recycled PE/PP filament, FL605R is made from recycled bottle caps and can deliver many of the same performance results as virgin PP filaments. Braskem has also become a leader in the utilization of recycled carbon fiber in its carbon fiber reinforced formulations, just another example of how materials producers are looking to deliver sustainable solutions to the market.