Filament Guide
PP Filament Guide
Living hinges and chemical tanks. Incredible material, terrible to print.
Last updated: March 2026
PP
Polypropylene
Living hinges and chemical tanks. Incredible material, terrible to print.
Advanced
Niche
Polypropylene is one of the most widely used plastics on Earth - it's in food containers, bottle caps, medical devices, automotive bumpers, and living hinge packaging. It has outstanding chemical resistance, true fatigue resistance (living hinges can flex thousands of times without breaking), and is one of the few polymers genuinely suitable for food contact in its base form.
Printing PP is another story. It warps aggressively - worse than ABS - because of its semi-crystalline structure and high shrinkage rate (~1.5-2%). It barely sticks to any standard print surface, and standard adhesion methods (glue stick, hairspray) don't work. You need either a PP-specific build surface (polypropylene packing tape works) or a dedicated PP adhesion sheet.
PP rewards patience. If you need chemical resistance, living hinges, or food-safe parts and you're willing to dial in the process, nothing else matches it. But this is not a filament for casual use.
Chemistry
Semi-crystalline polyolefin - chains of propylene monomers (CH₂=CHCH₃)
Print Temp
Heat Resistance
Softens at ~100°C - good thermal performance for a commodity plastic
Shrinkage
1.5-2% - extremely high. Design must account for dimensional change.
Chemical Resistance
Excellent - resists most acids, bases, solvents, and oils at room temp
Food Safe?
Base material is FDA-approved. Layer lines still harbor bacteria - coat or seal.
Pros
- True living hinges - flexes thousands of cycles
- Excellent chemical resistance to most substances
- Lightweight - lowest density of common filaments (~0.9 g/cm³) [2]
- Good heat resistance (~100°C)
- Food-contact safe base resin
- Excellent fatigue resistance
Cons
- Extreme warping - worse than ABS
- Almost no adhesion to standard print surfaces
- High shrinkage makes dimensional accuracy difficult
- Poor interlayer adhesion - parts delaminate easily
- Cannot be glued with standard adhesives
- Very limited color selection
- Enclosure nearly mandatory
Best Used For
Living hinges
Chemical containers
Food-safe prototypes
Automotive clips
Flexible snap-fits
Waterproof enclosures
Niche Tips
PP packing tape on the bed. The best adhesion surface for PP is... more PP. Apply clear polypropylene packing tape to your build plate - PP sticks to itself better than to anything else. Replace the tape every few prints as it wears.
Design for shrinkage. Scale your model up by 1.5-2% in the slicer to compensate. For precision parts, print a calibration cube first and measure the actual shrinkage of your specific filament brand.
Welding, not gluing. PP cannot be bonded with superglue or epoxy. For multi-part assemblies, use friction welding (spin a PP rod in a rotary tool against the joint) or a soldering iron to melt parts together.
PP-GF (glass-fiber reinforced PP) is significantly easier to print than pure PP - the glass fibers reduce shrinkage and warping. If you need PP properties without the printing nightmare, try PP-GF first.
Storage & Humidity
Target: below 40% RH. PP is one of the least hygroscopic filaments - it absorbs very little moisture compared to nylons or PETG. Storage is less critical but sealed is still best practice.
Drying: 55-60°C for 4-6 hours. Rarely needed unless the spool has been left open in a humid environment for weeks.
Bed Adhesion
Best surfaces: Polypropylene packing tape on the build plate, or dedicated PP adhesion sheets. Standard PEI, glass, and BuildTak do not work - PP's low surface energy means it won't bond to them.
Recommended bed temp: 80-100°C. Use a wide brim (10mm+) and an enclosure. Even with correct bed setup, large flat parts will likely warp - design with rounded corners and avoid large flat surfaces where possible.
Some users report success with PP on garolite (G10/FR4) sheets, which provide a mild mechanical bond. Worth trying if packing tape is inconsistent.
References
- Prusa Knowledge Base - Polypropylene (PP). Print temperatures, bed adhesion, and material properties. help.prusa3d.com/article/polypropylene-pp_167190
- Bambu Lab Wiki - Filament Guide Material Table. Density, temperature ranges, and properties for common filaments. wiki.bambulab.com/en/general/filament-guide-material-table
Recommended Gear
Build Surface
G10/Garolite build plate
PP barely sticks to anything. G10/Garolite is one of the few surfaces that provides reliable adhesion. PP tape on glass is the other option, but G10 is more consistent.
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Adhesion
Bed adhesive (Magigoo PP)
Magigoo PP is specifically formulated for polypropylene. Without specialty adhesion, PP prints will peel off the bed mid-print.
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Frequently Asked Questions
Why is polypropylene hard to print?
PP has extreme shrinkage (1.5-2%) which causes severe warping, making it one of the hardest materials to print flat. It also has very poor bed adhesion to most surfaces. PP requires a PP-specific build plate or packing tape bed surface, an enclosure, and careful tuning. Layer adhesion is weaker than most other filaments.
Does PP stick to the bed?
PP barely adheres to standard build surfaces like PEI, glass, or BuildTak. The best options are a polypropylene build plate (PP sticks to itself), wide packing tape (PP-based), or a specialized PP adhesion sheet. Glue stick and hairspray are generally ineffective. A heated bed at 80-100°C combined with a PP-compatible surface is essential.
What is PP filament used for?
PP excels in applications requiring chemical resistance, fatigue resistance (living hinges), and low density. Common uses include chemical containers, food packaging prototypes, living hinge mechanisms, and lightweight structural parts. PP is also semi-flexible, making it useful for snap-fit assemblies that need to flex repeatedly without cracking.
Is PP filament food safe?
Polypropylene is widely used in food packaging and is considered food-safe in its raw form. However, FDM-printed PP has the same layer-line hygiene concerns as all printed parts. PP's chemical inertness makes it safer than most filaments for food-adjacent use, but seal the surface for repeated food contact applications.