What Is 3D Printer Filament?

Filament is a thermoplastic raw material used as the core consumable in 3D printing technology to create three-dimensional objects. Typically supplied in spools, filament is heated and melted in the printhead extruder, then deposited layer-by-layer according to the digital model design.

Filament is commonly manufactured in 1.75 mm and 2.85 mm diameters, using different thermoplastic formulations and composite additives. Since material composition varies, filaments exhibit different properties in strength, flexibility, impact resistance, thermal behavior, color, surface finish, environmental durability, storage conditions, and service life.
They are used in a wide spectrum of applications—from hobbyist prints to industrial prototypes and end-use mechanical components.

Common Filament Types and Their Properties
PETG (Polyethylene Terephthalate Glycol-modified)

Flexible, durable, and easy to process

Typical printing temperature: 220–250°C

Suitable for transparent parts and food-contact-grade options exist

Moisture-sensitive; requires controlled storage

TPU (Thermoplastic Polyurethane)

High elasticity and impact resistance

Ideal for shock-absorbing parts such as automotive components and phone cases

High abrasion resistance

Slow printing process recommended due to flexible structure

PLA (Polylactic Acid)

Derived from renewable sources such as corn starch or sugarcane

Biodegradable and odor-free during printing

Typical printing temperature: 190–220°C

Rigid but brittle—recommended for non-structural or decorative parts

ABS (Acrylonitrile Butadiene Styrene)

High mechanical strength and fracture resistance

Printing temperature: 230–260°C

Used for robust parts such as automotive housings, toys, and electronic enclosures

Can emit odor during printing; requires ventilation

UV-sensitive in some formulations

Specialty Composite Filaments

Carbon-fiber-reinforced: Lightweight, high stiffness, matte finish

Wood-fill PLA: PLA + natural fibers for decorative appearance

Nylon-based: High strength and flexibility, but highly moisture-sensitive, must be stored dry

Preferred for mechanical parts requiring toughness and fatigue resistance

Filament Behavior and Key Design Considerations

Print temperature directly impacts mechanical performance and print quality.
Excessive temperature may degrade the polymer matrix and reduce reliability.

Thermal resistance varies by type:
ABS and nylon composites offer high heat tolerance, while PLA provides ease of processing.

Environmental sensitivity:
Nylon and ABS may require sealed or dry storage; PETG performs well against water and chemicals when properly processed.

Food-contact safety:
Only certified PLA or PETG food-grade filament should be used.
Due to the layered nature of FDM/FFF printing, 3D printed food containers may carry microbial retention risk unless post-processed or sealed.

How to Select the Right Filament

When selecting filament for a 3D printing project, the following must be evaluated:

Use case and functional requirement

Printer compatibility (heated bed, nozzle size, extrusion system)

Operating environment (indoor vs outdoor, humidity, UV, temperature)

Ventilation and safety constraints

Material cost and project budget

Examples:

Decorative parts → PLA

High impact mechanical parts → ABS

Flexible prints → TPU

Torque-driven or load-bearing compact designs → Carbon-fiber or nylon composites

Correct selection improves time-to-market, prototyping accuracy, thermal design efficiency, and product reliability.

Sensor or Actuator?

LDR = Sensor

Filament = Manufacturing material (not a sensing or actuation component)