Polypropylene (PP) is one of the world’s most widely used plastics, with many industrial and consumer uses. It’s also one of the most difficult materials to print with in 3D. However, once mastered, it has numerous advantages. Chemical resistance and relative flexibility are two advantages PP has over typical filaments like PLA. This makes this filament ideal for 3D printing. Here is our material guide for printing with polypropylene.
Common Uses of Polypropylene
Polypropylene is used in the automotive industry to make car bumpers. The use of PP results in parts that are both cost-effective and durable, able to tolerate bumps and bruises without breaking. Furthermore, this makes PP ideal for the production of toys.
PP is also FDA-approved, making it ideal for use in the packaging industry. Packages manufactured of PP, such as milk bottles, are inexpensive and long-lasting. Plastic lids for various candy receivers are a good example of Polypropylene’s mechanical resistance (i.e., Tic Tacs). Its flexural mode protects the material from breaking while repeatedly bending it open and closed. It is also better for the environment to switch to Polypropylene. It generates almost minimal waste, and parts made of polypropylene can be recycled numerous times.
Properties of Polypropylene
Polypropylene is one of the most attractive plastics on the market. It boasts a long list of amazing features, including but not limited to:
Polypropylene is well-known for its ability to withstand chemical environments that other polymers cannot. Acetone, chloride, boric acid, nickel carbonate, nickel sulfamate, hydrochloric acid, and other acids, alkalis, and organic solvents are all resistant to PP. It allows the material to be used in applications that need chemical contact.
More Prone To Bending & Better Resist Deformation Under Load Than PLA
When opposed to PLA, PP has a higher tendency to bend and can withstand more deformation under stress. This enables Polypropylene to be utilized in situations that require more bending (e.g., plastic lid for Tic Tacs). This can be useful for projects that require a lot of bending for them to function.
Polypropylene has the lowest density of all the polymers frequently used in manufacturing, making it extremely light. As a result, compared to PLA, more parts may be made from the same amount of PP. In fact, many companies who manufacture drones utilize PP for this exact reason!
Better Strength To Weight Ratio
Despite its lighter weight, polypropylene is prone to bending and can bear larger loads. As a result of this combination, the material has a higher strength-to-weight ratio than its competitors, making it a suitable choice for any wear-heavy application.
Low Melting Point
Despite the benefits listed above, polypropylene has certain drawbacks. The most important of these is its heat resistance. Polypropylene has a low melting point (160 °C) and is not suitable for applications requiring strong heat resistance. While this can be a detractor in some niche cases, for most applications this simply means that the plastic is easier to be formed and extruded evenly across a surface.
Why Is It Difficult To 3D Print With Polypropylene?
Why hasn’t Polypropylene made it into 3D printing yet? One of the main reasons is that printing Polypropylene filament has proven to be quite challenging. Because of the substantial warping that occurs during the printing process, most 3D printers find it difficult to regulate the output of PP prints. It appears that the material’s structure plays a part in why traditional methods of preventing warping have failed in the past.
Polypropylene is a semi-crystalline polymer, whereas PLA and ABS are amorphous polymers. This means that the material cools and hardens in a different way, causing much more stress within the material, thus warping. Nonetheless, with a little knowledge and practice, 3D printing with Polypropylene may be mastered.
How To 3D Print PP Filament
When printing with polypropylene, there are a few important things to keep in mind:
Stable Printing Temperature
Because polypropylene has a tendency to warp, it necessitates a steady printing chamber temperature (an enclosed chamber is highly recommended), a heated bed, and a high extruding temperature. The hot ends of most polymers may reach 220°C, while the bed temperature could reach 85°C. For this reason, consider making or buying a heated enclosure.
Consider Additional Adhesion
Polypropylene sticks strongly to polypropylene in general. A polypropylene generic sheet placed on top of the printing plate allows a polypropylene print to adhere properly and avoid warping. A double-sided tape (often made of polypropylene) could also be used.
Use Printing Settings from the Manufacturer
Normally, every 3D printer company tests all of the materials that their machines can print with and provides printing settings to their customers. If you don’t have much expertise with 3D printing, it’s probably best to stick to the manufacturer’s recommended settings. However, do not be afraid to experiment with different temperatures and print settings to finally tune your model to be how exactly how you want it!
The Potential of PP Filament
Is 3D printing’s next big thing going to be PP? Currently, the PLA retains the throne. However, we believe that allowing one material to remain on top for an extended period of time is never a good idea. PLA has advantages and disadvantages, and the advancement of this filament is causing PLA to advance as a material. Polypropylene, on the other hand, opens up many new possibilities, which is at the heart of 3D printing. Better hinge capabilities, chemical resistance, and a smooth surface finish are all features that will appeal to a wide range of consumers and industries.
We hope you have enjoyed our material guide covering polypropylene. If you are interested in the FDM 3D printing process and want to learn more be sure to reach out the tangible creative today. We have a rich library of resources to help you get started in 3D printing with the information that you need to know. Besides this we have a large collection of filament to ensure that we are your one stop shop for every and every 3D printing project.