Plastic packaging bag and preparation process thereof

The invention relates to the field of high polymer material processing, and particularly discloses a plastic packaging bag and a preparation process thereof. The plastic packaging bag is prepared from a polyvinyl alcohol film, and the polyvinyl alcohol film is prepared from the following raw materials in parts by weight: 35-50 parts of polyvinyl alcohol resin, 250-480 parts of water, 5-12 parts of a plasticizer, 2-10 parts of a sodium alginate solution, 5-10 parts of PMMA microspheres, 5-12 parts of a low-acyl gellan gum solution, 1-5 parts of a flatting agent and 1-3 parts of a defoaming agent. The preparation process comprises the following steps: uniformly mixing the polyvinyl alcohol resin and the water, adding the sodium alginate solution and the plasticizer, and uniformly mixing to obtain a primary mixture; adding PMMA microspheres and a low-acyl gellan gum solution into the primary mixture, uniformly mixing, finally adding a flatting agent and a defoaming agent, and uniformly mixing, so as to obtain a