The invention provides a leaf vegetable day-and-night filtering
diffraction induced resistance, bacteriostasis and
metabolism-regulating fresh-keeping film; a
preservative film inner layer is preparedby the following steps: putting a mixture into a three-layer co-
extrusion film blowing machine for co-
extrusion plasticizing to form a film, uniformly mixing 65% of
polypropylene plastic, 2% of ZnSO4, 8% of walnut peel carbon, 20% of nano CaCO3 and 4% of nano TiO2, granulating, blowing, and controlling the
processing temperature at 148-154 DEG C to obtain the
preservative film inner layer; a middle layer is composed of 70% of high-density
polyethylene, 6% of degradable plastic and 24% of nano CaCO3, and the
extrusion temperature is 240 DEG C; an outer layer is composed of 75% of linear low-density
polypropylene, 20% of degradable plastic and 5% of
red mud, and the extrusion temperature is 220 DEG C. Aiming at the problems of
chlorophyll degradation and yellowing,
pathogenic bacteria infection and rotting and massive accumulation of
ethylene in a fresh-keeping bag in the leaf vegetable storage process, a LED cold
light source is adopted for day and night
radiation, and a red filler isadded into the outer layer film of the fresh-keeping film to filter out light rays of other wave bands except
red light.