The more important performance index of packaging materials is air permeability, and the application field of this material in packaging can be determined according to the different air permeability of the material. Some packaging materials require oxygen permeability to supply enough oxygen to the product; some packaging materials require oxygen barrier properties in terms of materials, such as beverages and other packaging, require materials that can prevent oxygen from entering the packaging to inhibit mold The role of growth. PLA has gas barrier, water barrier, transparency and good printability.
Transparency
PLA has good transparency and gloss, and its excellent performance is comparable to cellophane and PET, which is a performance that other degradable plastics do not have. The transparency and gloss of PLA is 2 to 3 times that of ordinary PP film and 10 times that of LDPE. Its high transparency makes PLA as a packaging material beautiful in appearance.
Barrier
PLA can be made into film products with high transparency, good barrier properties, excellent processability and mechanical properties, and can be used for flexible packaging of fruits and vegetables. It can create a suitable storage environment for fruits and vegetables, maintain the life activities of fruits and vegetables, delay aging, and maintain the color, fragrance, taste and appearance of fruits and vegetables. However, when applied to actual food packaging materials, some modifications are needed to adapt to the characteristics of the food itself, so as to achieve a better packaging effect.
Antibacterial
PLA can form a weakly acidic environment on the surface of the product. It has a basis for antibacterial and antifungal. If other antibacterial agents are used in addition, it can achieve an antibacterial rate of more than 90%, and can be used for antibacterial packaging of products. Yin Min took Agaricus bisporus and Golden Ears as examples to study the fresh-keeping effect of the new PLA nano antibacterial composite film on edible fungi, thereby prolonging the shelf life of edible fungi and maintaining good quality status.
