Device and production process for preparing BOPP (Biaxially-oriented Polypropylene) packaging film

Abstract

The invention relates to the technical field of BOPP film manufacturing, and discloses a device and a production process for preparing a BOPP (Biaxially-oriented Polypropylene) packaging film. The device for preparing the BOPP packaging film comprises a positioning base, a motor, a thick sheet, a stripping roller, an extrusion die head and an air knife, wherein the positioning base is movably sleeved with a center roller; the center roller is fixedly sleeved with a movable roller; the top of the center roller is fixedly sleeved with a water inlet pipe; and the top end of the water inlet pipe is fixedly connected with a water distribution pipe. According to the device and the production process for preparing the BOPP packaging film provided by the invention, through designing an elastic rubber layer, a cavity, an extrusion plate and a spring, when cooling water in a cooling cavity flows downwards and absorbs heat of a thick sheet to cause temperature rise, the elastic rubber layer is softened, and gas in the cavity is thermally expanded, so that the extrusion plate is lifted upwards, the elastic rubber layer is expanded, a gap of the cooling cavity in an expanded area is reduced, the flow speed of the cooling water is increased, more heat is taken away in unit time, the top and the bottom of the cooling cavity are self-adjusted, and the cooling effect on each part of the thick sheet is uniform.

Description

technical field [0001] The invention relates to the technical field of BOPP film manufacturing, in particular to the preparation and production process of a BOPP packaging film. Background technique [0002] BOPP film manufacturing casting means that the molten polymer polypropylene is forced to pass through the narrow and long die under the pressure to form a viscous BOPP melt, and is quickly attached to the film under the strong blowing of the air knife. On the chilled roll, through the forced cooling and vitrification of the chilled roll, a slab with uniform thickness is formed. [0003] The cooling of the existing chilled rolls mostly uses the cooling water pipe inside the chilled roll for heat exchange cooling, but due to the length of the chilled roll and the large width of the slab, the cooling water entering from the water inlet passes through the front end of the slab Under the heat exchange, the cooling water temperature in the direction of the water outlet is hig...

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Problems solved by technology

[0004] Aiming at the deficiencies in the existing BOPP film manufacturing casting chill rolls in the use process proposed in the background technology, the invention provides a kind of preparation of BOPP packaging film And its production process, with water spray nozzles evenly distributed in the cooling chamber, cooling water diversion, temperature changes cause the elastic rubber layer to expand, cooling cavity gap changes make the cooling water flow rate change, cooling water impact forms a ladder to make the movable roller rotate, The advantages of changing the input amount of cold water and the flow rate of cooling water solve the technical problems in the above-mentioned background technology that uneven cooling of thick slices leads to warping and necking, and uneven cooling of thick slices leads to large differences in crystals of thick slices

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