The packaging industry has now become a major source of "white pollution", especially the waste accumulated throughout the year in the express delivery industry has caused a great burden on the planet. Therefore, in recent years, the packaging industry has vigorously promoted the 3R1D principles of packaging reduction (Reduce), reuse (Reuse), recycle (Recycle), and degradable (Degradable), and encourages the development of degradable packaging materials.
Compared with the traditional packaging material PE and PP, PLA has high transparency, good processability, and good printability. It has advantages when used as packaging materials. It can be made into films, foam materials and containers, such as flexible packaging bags and plastics bottles, cushioning materials, disposable tableware, etc.
PLA film
PLA film mainly includes high transparent film, heat shrinkable film, pellet blend blown film bag and PLA-based composite film.
PLA film can replace traditional film materials as a new packaging material. For example, Wal-Mart supermarket requires the use of fully degradable PLA film bags to replace traditional non-degradable PE bags. Japanese electronic products have also begun to use PLA nano-composite film packaging.
PLA container
Due to the degradability of PLA, PLA containers are mostly used in short-term shelf food packaging.
The transparency and oxygen barrier of PLA bottles are better than PE bottles. Nature Works uses PLA bottles to package organic juice drinks, which can guarantee a 60-day shelf life. The Danish Faerch Plastics Company uses PLA to package low-temperature pasta, meat, salads and other fresh foods, which can achieve a long shelf life. The European market has launched PLA-made yogurt cups and beverage packaging bottles, which can meet EU standards for food containers.
The highly transparent and heat-resistant PLA water bottles and PLA baby bottles developed by PLALEAVES can meet the application conditions that are both transparent and heat-resistant (water bottles and baby bottles require heat-resistant temperature ≥100 ℃). At the same time, PLALEAVES also coats PLA on paper to make coated paper cups, which are used in various waterproof and oil-proof food packaging.
PLA foam material
PLA foaming material is also biodegradable and can be used to produce disposable catering utensils (such as fast food boxes, instant noodle bowls, etc.) and cushion packaging without white pollution.
Compared with traditional PE and PP materials, PLA has a higher melting point (about 180 ℃) and better processability. The hardness and mechanical properties of PLA are similar to those of traditional resins, with good transparency and excellent gloss, etc., so it is especially suitable for packaging materials.
However, compared with high-barrier nylon, polyvinylidene chloride, etc., PLA has poor oxygen and water vapor barrier properties, insufficient protection for oily foods, and PLA has poor toughness, low heat distortion temperature, and poor impact resistance. It is often unable to meet the requirements of circulation in harsh environments. In addition, the degradation cycle of PLA is not well controlled. Compared with traditional resins, the price is slightly higher (about 30,000 yuan/ton). At this stage, it is not advantageous for packaging.
Although PLA has shortcomings such as brittle texture, heat-insensitiveness, and poor barrier properties, these shortcomings can be corrected by modification such as copolymerization, blending, and plasticization.
