material-selection

How to Choose Filament for Functional Parts

Functional parts face real stress. Here's how to match material properties — strength, temperature, and flexibility — to your application.

5 min read

Functional parts fail when material properties don’t match the application. Match three properties to your use case: mechanical load (strength), operating temperature (heat resistance), and environmental exposure (chemical/UV resistance).

Step 1: Define the Load

Load TypeBest MaterialWhy
Static (constant weight)PETGGood creep resistance
Dynamic (repeated stress)PETG-CFCarbon fiber reinforcement
Impact (sudden force)PETGHigh impact resistance
Torque (twisting)PETG-CFBest layer adhesion

Step 2: Define the Temperature Range

Operating TempMaterial Choice
Below 50°CPLA, PETG
50-80°CPETG
80-100°CASA
Above 100°CConsider industrial materials

Step 3: Define the Environment

EnvironmentRiskSolution
Outdoor (UV)Photo-degradationASA
Humid/wetMoisture absorptionPETG (sealed)
Chemical exposureDissolutionCheck MSDS compatibility
Abrasive contactSurface wearPETG-CF

Step 4: Validate

Before committing to production, print a test piece in the actual orientation it will be used. Layer direction affects strength — parts loaded parallel to layers are weakest at layer interfaces.

Individual results depend on your printer, environment and application.