Comparison and application of PLA filament and PETG filament
PLA (Polylactic Acid)
Polylactic Acid is to 3D printing what training wheels are to bicycles. It’s incredibly easy to print on even the cheapest 3D printers. With print temperatures beginning as low as 180°C, you don’t need an all-metal hot end to print this filament safely. PLA doesn’t even require a heated bed, as long as the ambient room temperature is maintained above 20°C.
PLA Filament Properties
Printability: Excellent
Color Selection: Excellent
Heat Resistance: Poor
Tensile Strength: Excellent
Toughness: Poor
UV Resistance: Excellent
Moisture Resistance: Excellent
Creep Resistance: Poor
When Should You Use PLA 3D Printing Filament?
PLA is great for cosmetic 3D prints but not so much for anything else. Despite its high tensile strength, it lacks toughness because the material is too hard to flex. This makes it brittle and susceptible to cracking in applications requiring impact resistance and bending. Its low-temperature printability also translates into poor heat resistance. PLA prints warp when subjected to direct sunlight or in-car conditions due to the material’s low glass transition temperature of 57°C.
PLA’s tendency to creep, or to permanently deform under load at room temperature, makes it unviable for any functional print that either uses fasteners or serves any load-bearing purpose. Consequently, most 3D printing enthusiasts move to other materials once they have mastered slicer settings and 3D printer tuning with PLA.
PETG (Polyethylene Terephthalate Glycol)
PETG should ideally be your second filament challenge once you have mastered PLA. It is quite similar to the plastic found in water bottles and food containers, except for the addition of glycol to improve printability. PETG is better than PLA in most important parameters. It’s slightly tougher, significantly more heat resistant, exhibits excellent creep resistance, and is therefore suitable for functional 3D printing.
PETG Filament Properties
Printability: Good
Color Selection: Good
Heat Resistance: Average
Tensile Strength: Good
Toughness: Good
UV Resistance: Excellent
Moisture Resistance: Poor
Creep Resistance: Good
When Should You Use PETG 3D Printing Filament?
PETG is the perfect compromise between PLA and the much superior ABS filaments. While it lacks the higher temperature resistance of ABS, it is still good enough for prints to be used outdoors or car interiors. It is also considerably tougher than PLA and ideal for applications where impact resistance is desired. PETG’s resistance to creep also makes it ideal for functional prints and 3D printer components alike.
