PLA biodegradable materials are one of the hotspots that have received the most attention from domestic and foreign research. After the release of the plastic restriction order, PLA has received widespread attention as an alternative to traditional plastics. Among them, degradable plastic bags and degradable straws are research hotspots. Today, I do not pay attention to these two directions, and talk about film applications, mainly for food packaging.
First of all, the most important performance index of packaging materials, especially food packaging materials, is air permeability. Different application fields can be confirmed according to the air permeability of the materials. PLA material itself has gas barrier, water barrier, transparency and good printability. On some packages such as fruit and melon drinks, oxygen can be prevented from entering the package to achieve the effect of inhibiting the growth of mold.
The transparency and gloss of PLA are equivalent to cellophane and PET materials, with excellent performance. Moreover, the transparency and gloss of PLA far exceed that of ordinary PP film, and it is 10 times that of LDPE.
PLA can prepare film products with excellent performance, not only in transparency, but also in good barrier properties. Provide a suitable storage environment for fruits and vegetables to maintain their freshness.
PLA can form a weakly acidic environment on the surface of the product, which can inhibit bacteria and mold. Other antibacterial agents can also be used as an aid, and the antibacterial rate can reach more than 90%. Some scholars have studied and compared LDPE film, PLA film and PLA/REO/AgO hybrid film for comparison, and the hybrid system does perform better in terms of antibacterial properties. From the perspective of preservation effect, PE cling film and PLA film were compared, and they both covered broccoli uniformly. Finally, it was found that PLA film can extend broccoli by 1 to 2 days.
