Flexible heat-shrinkable composite film formed by tape casting and preparation method of flexible heat-shrinkable composite film

Abstract

The invention relates to a flexible heat-shrinkable composite film formed by a tape casting. The flexible heat-shrinkable composite film formed through tape casting is of an A / B / A three-layer composite structure, and the A layer is a surface layer and is mainly made of a mixture of PETG resin and an anti-blocking agent; and the layer B is a core layer and is mainly prepared from styrene-butadienesegmented copolymer (SBS) resin and maleic anhydride (MAH). The invention also provides a preparation method of the flexible heat-shrinkable composite film formed by tape casting. The heat-shrinkablecomposite film prepared by the method has the characteristics of wide shrinkage range, good flexibility, excellent printing performance and the like, and the phenomena of local pattern deformation, poor circular arc shrinkage and the like in the label sleeving process caused by high rigidity of a PETG film are avoided; and besides, the phenomena of film surface wrinkling and film layer separationcaused by inconsistent shrinkage of surface layer and core layer materials of a common composite film are avoided. The heat-shrinkable composite film prepared by the method has a wide market application space.

Description

technical field [0001] The invention relates to the technical field of processing heat-shrinkable composite films, in particular to a flexible heat-shrinkable composite film formed by tape casting and a preparation method thereof. Background technique [0002] Heat-shrinkable sleeve label belongs to the sleeve label, which is a film label printed on heat-shrinkable plastic film or plastic tube with special ink. When the label is heated, the shrinkable label will quickly shrink along the outer contour of the container. Clings tightly to the surface of the container, creating the effect of "from head to toe" all-round packaging of the bottle. [0003] The heat shrinkable films currently used in the packaging field mainly include polyvinyl chloride (PVC) heat shrinkable films, polyethylene (PE) heat shrinkable films, polystyrene (PS), modified polyethylene terephthalate ( PETG) heat shrinkable film, multi-layer co-extruded polyolefin heat shrinkable film (POF), etc. Existing ...

AI Technical Summary

Problems solved by technology

[0004] PVC heat shrinkable film has good printing performance, high transparency and good gloss, but the shrinkage rate generally does not exceed 60%. It is limited in some special-shaped bottles or applications requiring high shrinkage rate (shrinkage rate above 60%), and PVC film Contains plasticizers and cannot be recycled;

[0005] PE and POF heat shrinkable films have good flexibility, impact resistance, strong tear resistance, are not easy to break, are not afraid of moisture, and have a wide shrinkage range (the shrinkage rate can be adjusted up to 80%), but the printing performance is not good;

[0006] PS shrink film has good light transmittance and gloss, relatively low stiffness, and wide shrinkage range, but it is sensitive to temperature, requires relatively high storage conditions, and is prone to cracking problems during use. In addition, PS heat shrinkable films must use special Printing with ink and solvent, the cost is higher

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