3D Printing Guide: Polypropylene

Polypropylene (PP) is a widely used thermoplastic material made from a semi-crystalline polymer. It is semi-rigid in nature and has excellent fatigue resistance, making it ideal for packaging and storage applications where a tough but semi-flexible material is needed.

Polypropylene has many applications but is mostly prevalent in the automotive and packaging industries because of its cost-effectiveness and ability to flex without breaking. It is ideal for bumpers and high fatigue parts as well as containers and consumer packaging.

Because polypropylene is a semi-crystalline polymer it is prone to warping as it cools. This creates a steep learning curve for those new to 3D printing. For the best results, it requires a well set-up printer, print surface and chamber to regulate temperature, mitigating any potential warpage.

Printing Specifications

Print Temperature
210-230° C Depending on Type

Bed Temperature
85-100° C

Glass Transition Temperature

55-60° C

Print Performance: Has difficulty adhering to build surface with potential to warp when not using a proper set up
Strength: Lower strength compared to rigid materials, but has excellent fatigue resistance
Fumes:
Best used for: Applications needing flexibility with resistance to fatigue such as food containers or living hinges
When not to use: Not an ideal material for high strength applications

Best Practices

Ensure proper bed adhesion
- As with any print, proper bed adhesion is a critical element in a successful print. Polypropylene has a difficult time sticking to a most bed surfaces but sticks well to itself. For the best results, use polypropylene packing tape but pay close attention to the bed temperature as most packing tape has a melting point of 90°C.
Optimal print environment
- Since polypropylene is prone to warpage, it is highly suggested to use a heated enclosed chamber to help mitigate or eliminate warping. Using a chamber heated to approx. 45-60°C is optimal for printing polypropylene.
Use a raft
- Rafts are usually avoided if possible, however, since polypropylene adheres well to itself and packaging tape is made out of polypropylene, it is recommended to use a raft as a sacrificial layer.