Polypropylene (PP) is one of the most used plastics in the world with a wide range of industrial and consumer applications. Printing this material in 3D has always been near impossible, until the Bolt Pro.
Our vision here at Leapfrog 3D Printers is to take more advantage of Fused Filament Fabrication. The freedom we offer within printing materials opens more possibilities for the 3D printing industry. PP has advantages over standard filaments like PLA so 3D printing PP can be the next big thing.
Why is it difficult to 3D print PP?
In addition to the benefits and features of PP above mentioned, the material has its benefits over PLA. So, why has it not yet landed in 3D printing? One of the reasons is mainly because Polypropylene filament proved to be very difficult to print. Most 3D printers find it hard to control the results of PP prints because of the heavy warping that takes place during the printing process. Thus, it is believed that the structure of the material plays an important role on why the conventional tricks to prevent warping had not worked before. PLA and ABS are amorphous polymers, whereas Polypropylene is semi-crystalline. This means that the material cools and solidifies differently, resulting in much more stress within the material, thus, warping.
Nevertheless, Leapfrog 3D Printers together with Verbatim have succeeded printing polypropylene on the Bolt Pro. Verbatim filament provided the right attributes to demonstrate how the Bolt Pro can print PP, providing a perfect result with this demanding type of plastic.
Common uses of Polypropylene
The chemical resistance of PP allows a wide use of this material. For instance, the medical industry uses polypropylene containers, since it is able to store substances without contaminating them.
Additionally, the automotive industry uses polypropylene for creating car bumpers that result in a cost efficient and resistant part, able to withstand bumps and bruises without breaking. This makes it also extremely applicable for toys.
It is also FDM approved, which makes it ideal for the packaging industry. The use of PP as a bottle for milk results in a cheap and durable package. However, the mechanical resistance of Polypropylene is well exemplified by the plastic lids for different candy recipients (i.e., Tic Tac). Its flexural modus prevents the material to break while opening and closing it through repeatedly bending.
Switching to Polypropylene is also beneficial for the environment. It produces almost no waste and the parts from PP can be recycled multiple times.
Polypropylene is one of the most requested type of plastics in the industry. It has impressive mechanical properties, combined with high chemical resistances.
PP has a larger tendency to bend compared to PLA and it can resist deformation better under a load. It is lighter and gives a better strength-to-weight ratio. One of the main properties of polypropylene is resistance towards chemicals such as acids, alkalis and organic solvents.
The potential of PP filament
Is PP going to be the next big thing in 3D printing? At the moment PLA still holds the throne. We think that it is never good to let one material stay on top for so long.
The combination of Verbatim PP filament and the Leapfrog Bolt proved to be a successful partnership. This pair shows that the bar of FFF 3D printing is still being set higher everyday. PLA has its pros and cons, and the development of this filament makes PLA grow as a material as well. However, Polypropylene enables new possibilities, which is the heart of 3D printing. Better hinging capabilities, better chemical resistances and a good surface finish; these are the things that will appeal to a lot for unique users and specialised industries. And right now, our unique experience with the Leapfrog Bolt 3D printer feels right at home in these niches.
Want to see PP prints of the Bolt for yourself? Request a sample on our sample page.
How to print PP filament
Printing polypropylene was one of the greater challenges to the Leapfrog Bolt Pro printer. Also, after completing this task with full success, it is confirmed that the Bolt Pro is suitable for any type of material, since trials have been made with Flex, Nylon and Polycarbonate, all resulting in successful prints.
For this test, we have printed two Benchy boats: one using regular blue PLA and the other one using Verbatim transparent PP filament developed by the Mitsubishi Chemical Holdings Group. Verbatim advised to print PP on 220°C, but we found, after testing, that printing at 170°C provided better results on the Bolt Pro. Because of the closed chamber and heated bed, the Bolt can easily keep track on the temperature of the print, overcoming the challenges with the structure of the material and preventing warping of the print. Combined with the Direct Drive, the Bolt provides optimum control for printing the PP filament. We have tested 3 times, and the third test gave the best results.
Resisting chemicals with Polypropylene
To put both prints and materials to the test, we came up with the following setup. Both Benchy boats were put into a liquid until one sinks. In order to make it more interesting, we have used Dioxolane instead of water. Dioxolane is a chemical solvent often used in coatings, foils/films, paint coatings, paint removers, film coating removers and general cleaning solvents.
After 2 hours, the first signs of decay of the PLA boat began to appear, while the PP boat was still going strong. It took a bit longer to get the PLA boat to dissolve completely, but the blue colour in the Dioxolane clearly showed where the blue PLA Benchy did go.
watch the full video here
If you already own a Bolt, visit Verbatim to get this amazing filament.
Want to know how to use polypropylene 3D printing in your business? Request a free consultation.