PP

PP (polypropylene) is the plastic of food containers and car bumpers. Light, chemical-resistant, with unique fatigue strength: a PP living hinge can flex thousands of times without breaking. But PP is very hard to print — it sticks to almost nothing, including the bed, and warps heavily.

What it is good for

• Chemical-resistant containers and tubs
• Living hinges, reusable flexible latches
• Lab ware, parts in contact with aggressive media
• Light fatigue-resistant parts

Where NOT to use it

• Without the right adhesion surface — PP will not stick to normal beds
• Tight-tolerance dimensional parts — heavy shrinkage
• Loaded rigid parts — PP is soft and creeps
• Beginners — it is one of the hardest filaments

How to print

• Nozzle temperature: 220–250 °C
• Bed temperature: 80–100 °C
• Cooling: 0–30%
• Enclosure recommended — reduces warping
• Adhesion: only a matched surface — packing PP tape on the bed or PP adhesive. PP does NOT stick to PEI or glass
• Speed: 30–50 mm/s

Drying and storage

PP is mildly-to-moderately hygroscopic — drier than nylon, but moisture still hurts the print.

• Drying: 55–65 °C for 4–6 hours
• Storage: dry box with silica gel
• Signs of moisture: bubbling, worse surface

Pros and cons

• Excellent chemical resistance
• Unique fatigue strength — living hinges
• Light and flexible
• Moisture-resistant

• Very difficult bed adhesion
• Heavy warping and shrinkage
• Low stiffness
• Hard for beginners