This is a general-purpose guide for understanding any filament TDS.
By the end of this guide, you will know:
- What every property actually means in real life
- How to compare different materials
- How to predict part behavior before printing
- How to choose the right filament for the job
- How to avoid common misunderstandings
This turns a TDS from a confusing spec sheet into a practical decision tool.
A TDS is a standardized material reference document. It tells you:
- How the material behaves when heated
- How it flows during extrusion
- How strong the printed parts are
- How stiff, brittle, flexible, or tough parts will feel
- What print conditions were used for testing
Think of a TDS as: A material behavior map.
*Important n Note: TDS values describe material capability, not guaranteed print results. Printer, slicer settings, part design, cooling, infill, orientation, and environment all affect real-world performance.
Check how the samples were printed and tested. Typical information includes:
- Nozzle temperature, print speed, infill percentage
- Nozzle size, bed temperature, cooling, conditioning time
Why this matters:
- 100% infill = higher strength than 20% infill
- Higher nozzle temp = better layer bonding
- Faster print speed = weaker Z strength
- Strong cooling = more brittle parts
What it is: Mass per volume (g/cm³)
- Meaning: weight of a part for its size, plus indirect info about polymer structure.
- Higher density: heavier parts, tightly packed chains, often higher stiffness, better dimensional stability
- Lower density: lighter parts, flexible, better shock absorption, more elastic behavior
Filament Examples:
- Low density: TPU, flexible filaments
- Medium density: PLA, PETG
- High density: carbon fiber, glass fiber, metal-filled filaments
Design Relevance: weight-sensitive parts, drones, robotics, wearables, structural calculations.
What it is: Temperature where material starts to deform under load
Indicates the real heat resistance limit of printed parts
- Low Vicat: PLA (~55–65 °C)
- Medium Vicat: PETG (~80 °C)
- High Vicat: ABS, Nylon, PC (>100 °C)
What it is: How easily molten plastic flows
- High MFI = easy flow, smooth surface, better detail, weaker layer bonding, lower mechanical strength
- Low MFI = harder flow, stronger layer bonding, higher strength, more structural integrity
Filament Examples:
- High MFI: PLA+, TPU, flexible filaments
- Low MFI: Nylon, PC, CF-Nylon, filled engineering polymers
What it is: Solid → liquid phase change temperature
Indicates a material transition point, not print temperature or heat resistance
Vicat vs Melting: Vicat = real-world heat limit; Melting temp = material science value
PLA melts ~150 °C, softens ~60 °C → deforms long before melting
Meaning: Resistance to deformation
- High = stiff/rigid;
- Low = flexible/elastic
Note:
- Young’s modulus = structural stiffness;
- Shore hardness = surface softness
TPU can be soft to the touch, but still structurally stiff if thick.
Filament Examples:
- High modulus: PLA, carbon fiber, nylon
- Low modulus: TPU, flexible filaments
- X-Y: Strength along layers → structural strength, load capacity
- Z: Layer-to-layer bonding → orientation critical, vertical parts weaker
Examples:
PETG > PLA for toughness; Nylon > PETG for load resistance
Low = brittle
High = ductile/elastic
Filament Examples:
PLA (brittle), PETG (semi-ductile), TPU (highly elastic)
- Modulus = initial resistance to bending
- Strength = force before failure
Examples:
PLA rigid, PETG semi-flexible, TPU flexible
Resistance to sudden shocks
Examples: PLA low, ABS high, TPU shock-absorbing
- Thermal: Will the part survive the temperature? → Vicat, HDT, Tg
- Mechanical: Will the part survive the forces? → Modulus, strength, impact, elongation
- Density = weight + structure
- Vicat = heat survival
- MFI = flow vs strength
- Melting temp = phase change, not usability
- Modulus = stiffness
- Strength = failure point
- Elongation = brittleness vs ductility
- Impact = shock survival
- X-Y = in-layer, Z = between layers