Polylactic Acid (PLA), scientifically known as polylactide, is a novel bio-based and biodegradable plastic. It is primarily derived from renewable plant resources such as corn and cassava through the extraction of starch. Owing to its environmentally friendly characteristics and favorable properties, PLA has found extensive applications across various fields.
Core Characteristics of PLA (Basis for Application)
- Eco-Degradability: Under industrial composting conditions (specific temperature, humidity, and microbial activity), PLA can decompose into carbon dioxide and water within several months, positioning it as a potential solution to “white pollution.”
- Bio-based Origin: Sourced from renewable plants, it reduces dependence on petroleum resources.
- Good Mechanical Properties: Exhibits high strength and modulus, making it suitable for many disposable products and packaging applications.
- Biocompatibility and Safety: Approved as a safe material by the U.S. FDA, it can be used in food contact and medical fields.
- Ease of Processing: With a relatively low melting point, it is easily processed through methods like injection molding, extrusion, and 3D printing.
- Limitations: Relatively poor heat resistance (typically below 60°C), inherent brittleness, and slow degradation in natural environments (requiring industrial composting conditions).
Primary Application Fields
PLA applications can be broadly categorized into the following main areas:
- Packaging Sector (Largest Application Market)
This is the earliest and primary application area for PLA, aimed at replacing traditional petroleum-based plastics like PS, PP, and PET.- Food Containers: Transparent cold drink cups, salad boxes, fruit containers; takeaway containers, fast-food packaging (note: heat resistance limitations apply).
- Packaging Films: Shrink wrap for vegetables and fruits; outer packaging bags for goods.
- Foamed Materials: Substitute for expanded polystyrene (EPS) as cushioning packaging material, e.g., electronic product trays, fresh produce insulation boxes.
- Bottles: Used for packaging water, juices, dairy products, and other short-shelf-life items.
- 3D Printing (Fastest-Growing Sector)
PLA is one of the most popular materials (filaments) for 3D printing, especially suitable for beginners and makers.- Advantages:
- Easy Printing: Odorless during printing, low shrinkage, minimal warping, high success rate.
- Rich Color Variety: Easily colored, available in various colors and special effects (e.g., glow-in-the-dark, color-changing).
- Good Surface Quality: Produces models with smooth surfaces and clear details.
- Application Scenarios:
- Prototyping, product design verification.
- Educational models, artistic creations, personalized accessories.
- Toys, Cosplay props.
- Simple functional parts.
- Advantages:
- Textile Fibers
PLA can be spun into fibers similar to polyester (PET), used to create eco-friendly textiles.- Non-woven Fabrics: Used for shopping bags, facial masks, wipes, tea bags, etc.
- Apparel Fibers: Fabrics made from PLA offer moisture-wicking, breathability, and soft texture.
- Stuffing: Alternative to down or synthetic fiberfill, used in toys, pillows, and quilts.
- Medical and Hygiene Fields
Leveraging its biocompatibility and biodegradability, PLA holds significant value in the medical sector.- Absorbable Medical Devices: Surgical sutures, bone screws, bone plates, drug delivery systems. These implants degrade within the body after serving their purpose, eliminating the need for secondary removal surgery.
- Disposable Medical Supplies: Intravenous bags, test tubes, Petri dishes.
- Hygiene Products: Backsheets and top sheets for diapers and sanitary napkins, favored for their breathability and environmental benefits.
- Consumer Goods
- Disposable Tableware: Knives, forks, spoons, straws, etc., serving as primary substitutes under “plastic bans” in many regions.
- Stationery: Rulers, folders, ballpoint pen casings.
- Household Items: Flowerpots, toothbrush handles, combs.
The components pictured are injection-molded products manufactured by ATC-Mould for a client. These parts were produced by reusing and recycling material from the client’s used 3D-printed prototypes.