Heat-shrinkable PETG black and white composite film with light shielding performance

Abstract

The invention relates to a heat-shrinkable PETG black and white composite film with light shielding performance. The film adopts an A-B-C structure, wherein the A layer is a printing layer and is madeof a mixture of PETG resin and an anti-blocking agent; the layer B is a white structural layer and is made of a mixture of PETG resin and a white additive; and the layer C is a black structure layerand is made of a mixture of PETG resin and a black additive. A preparation method comprises the following steps of: enabling the three materials to pass through three sets of extrusion and filtrationsystems to obtain three melts, converging the three melts to a T-shaped die head to extrude a cast sheet, and carrying out a two-way stretching, shaping, traction and winding process to prepare the heat-shrinkable PETG black and white composite film. According to the invention, the problem of short shelf life of the product caused by the fact that an existing common PETG transparent film cannot block infrared rays, visible light, ultraviolet rays and the like is effectively solved, so that costs of production, transportation, storage and the like of dairy products, lactic acid bacteria products, et. are greatly reduced.

Description

technical field [0001] The invention relates to the field of packaging materials, in particular to a heat-shrinkable PETG black and white composite film with light shielding performance. Background technique [0002] In recent years, with people's increasing requirements for quality of life and increasing awareness of environmental protection, the emergence of PETG heat shrinkable film packaging products has made up for many of the existing packaging products made of PVC, OPS and other materials in terms of processing and use. Defects, become a real green product. The full English name of PETG is Poly (ethyleneterephthalateco-1,4-cylclohexylenedimethylene terephthalate), which is a transparent, non-crystalline copolyester, and the comonomer commonly used in PETG is 1,4-cyclohexanedimethanol (CHDM, Cylclohexylenedimethylene ), the full name is polyethylene terephthalate-1,4-cyclohexanedimethanol ester, which is composed of terephthalic acid (PTA), ethylene glycol (EG) and 1,...

AI Technical Summary

Problems solved by technology

[0004] However, the ordinary PETG transparent film has almost zero functions of blocking infrared rays, visible light and ultraviolet rays. With the needs of market development, the demand for dairy products and lactic acid bacteria products is gradually increasing, and the shelf life of these products is short. Greatly increased production, transportation, storage and other costs

Obviously, ordinary PETG transparent films cannot meet the needs in this regard, and there is an urgent need to develop PETG films with functions such as blocking visible light.

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