Meaning
Aliphatic polyester produced from fermented plant starch provides a prominent biodegradable option in the packaging and consumer goods markets. Poly lactic acid is derived from renewable resources such as corn or sugar cane rather than petroleum. This material is widely used for 3D printing filaments and transparent containers.
Thermal Sensitivity
Low glass transition temperature and a narrow processing window limit the applications where this resin can be used. Poly lactic acid begins to soften at approximately 60 degrees Celsius, making it unsuitable for hot-fill containers or automotive interiors. Overheating the melt during processing causes rapid degradation and a loss of mechanical strength.
Processing Requirement
Rigorous drying and precise temperature control are necessary to prevent hydrolytic degradation. Poly lactic acid must be dried to a moisture level below 250 parts per million to ensure a stable injection or extrusion process. A moulder must also manage the cooling rate carefully because the material crystallizes slowly, which can lead to parts sticking in the tool.
Mechanical Property
Tensile strength and stiffness of this polymer are comparable to polystyrene, but it lacks the impact resistance of tougher resins. Poly lactic acid is inherently brittle and often requires the addition of impact modifiers for technical applications. Despite these limitations, its high clarity and ease of printing make it a common choice for prototyping and short-run production.
The material is also compostable under industrial conditions, which helps to address end-of-life concerns for single-use items.
