What should we pay attention to when processing PVC film?

Each kind of plastic film has its own characteristics, and these factors must be fully taken into account when processing. Next, the precautions of PVC polyvinyl chloride plastic film in printing, printing materials, bag making, bonding and use will be described in detail.

(1) printing of 1)PVC polyvinyl chloride plastic film. Because the printing ink of offset printing (also called offset printing or pad printing) can't be compatible with PVC film (that is, the adhesive force of offset printing ink on PVC film is poor), and the printing plate of relief printing will be swollen and corroded by PVC ink, so it can only be printed by gravure printing and screen printing. Because the PVC film will soften and deform at 60-70℃, the printing can't match the printing plate, let alone the accuracy of overprinter, so the drying temperature of the drying box can't be higher than 60℃ during printing, and the drying temperature for general printing is 20-30℃. If it is printed by gravure printing machine of direct heating drying box, then the heating of drying box can't be turned on, just turn on the air blower.

(2) Printing ink for 2)PVC polyvinyl chloride plastic film. The principle of printing ink for plastic film is what kind of performance plastic ink is used for plastic film, that is, the adhesive (resin) of the ink has the same performance as the printed PVC film, so that there will be affinity and good combination. PVC film will swell and dissolve in aliphatic, ketone, aromatic and halohydrocarbon solvents, so you can't use chlorinated polypropylene composite ink containing a lot of aliphatic and ketone. When using polyamide surface printing ink, beware of softening agent precipitation in PVC film, which will make the ink stick back and cause film adhesion. In addition, when using PVC special ink, it should also be noted that the amount of ink applied should not be too large, otherwise the PVC film will be swollen and dissolved by cyclohexanone solvent in the ink, resulting in coarsening or wrinkling of the film surface.

(3) The bag-making of 3)PVC polyvinyl chloride plastic film can't be heat-sealed by direct heating and pulse sealing machine. If the bag is made by direct heating, the film surface of the bag will shrink and wrinkle, and the tightness of the seal is poor. High-frequency or ultrasonic heat sealing and hot cutting machine can be used for heat sealing.

(4) The bonding of 4)PVC polyvinyl chloride plastic shrink film, that is, the bonding of shrink bottle label interface used in many plastic bottles such as beverages, fruit juices and mineral water. Usually, perchloroethylene resin glue is used for bonding. The glue is made by dissolving 40% ~ 45% perchloroethylene resin with 55% ~ 60% cyclohexanone solvent. Only the amount of glue should not be too large, otherwise the solvent of glue will dissolve the film and cause adhesion.

(5) PVC film added with plasticizer dioctyl formate, dibutyl formate or dioctyl diacrylate and dibutyl acid has many advantages, such as softness, large elongation, high strength, impact resistance, aging resistance, etc., but it has a big smell, so it can't be used as packaging for direct contact with food.