Preparation method of pinhole-free PVDC casing film

• Main Authors: NI XIANGBIN, TIAN JIANXIN, BAI HAIYING
• Format: Patent
• Language: Chinese; English
• Published: 11.04.2023
• Subjects: AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; PERFORMING OPERATIONS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

The invention relates to the technical field of packing materials, and particularly discloses a pinhole-free PVDC casing film preparation method, which specifically comprises: placing PVDC resin and EVA resin in a mixing machine, and starting mixing and heating; adding the heat stabilizer, the DBS plasticizer, the lubricant and the pigment when the mixture is heated to 40-45 DEG C, and continuing mixing and heating; when heating to 80-85 DEG C, stopping heating, continuously mixing, discharging, and curing at room temperature; s2, placing the cured mixture in the step S2 in a screw extruder for melt extrusion, blowing to form a blank, and drawing to form a film; and feeding into a drying oven at 105-110 DEG C for 20-30 minutes, and then rolling. The VA content of the EVA resin is strictly controlled to be 28 +/-2%, the EVA resin is well compatible with the PVDC resin, the crystallization speed and crystallinity are properly reduced, and the casing film which is good in low-temperature toughness, high in stren