Thermal shrinkage biaxially oriented film

Abstract

The invention discloses a thermal shrinkage biaxially oriented film which is composed of a surface layer, a sandwich layer and an inner layer, wherein the thickness of the surface layer is 0.5-1.5 micrometers, the thickness of the sandwich layer is 19-22 micrometers, the thickness of the inner layer is 0.5-1.5 micrometers, and the total thickness of the three layers is 20-23 micrometers. The surface layer comprises the following components in percentage by weight: 97-99% of acrylic resin copolymer, 0.5-2% of lubricant and 0.1-1% of antiblocking agent. The sandwich layer comprises 80-93% of acrylic resin homopolymer, 0.3-3% of anti-static agent, 0.1-0.5% of crystal regulator, 1-2% of surfactant, 5-18% of stiffening agent and 0.5-1% of lubricant. The inner layer comprises 97-99% of acrylic resin copolymer, 0.5-2% of lubricant and 0.1-1% of antiblocking agent. The film has a stable thermal shrinkage factor which slightly changes as the storage time changes.

Description

technical field [0001] The invention belongs to the technical field of heat-shrinkable stretched films. In particular, it relates to a heat-shrinkable biaxially stretched film. Background technique [0002] The Chinese invention with the publication number of 1425549 on June 25, 2003 discloses a method for producing biaxially stretched polypropylene cigarette film by the foam tube method. Compounding, extrude the primary tube film through the co-extrusion die on the extruder, quench the primary tube film, and then preheat it in a preheating oven with a temperature of 260°C-400°C. The transverse inflation and longitudinal stretching are carried out in an oven at ℃, the stretching temperature is 135°C-150°C, the longitudinal stretching ratio is 6.5-8.0, and the transverse stretching ratio is 5.0-8.0; Roll, slitting, rewinding, slitting again. Compared with the existing production technology of flat-drawing biaxially stretched polypropylene cigarette film, this production pr...

AI Technical Summary

Problems solved by technology

If the cigarette film is stored for a long time or the storage temperature is too high, it may cause the heat shrinkage rate of the cigarette film to attenuate too much, which will affect the packaging effect of the cigarette. This situation is more likely to occur in summer

Therefore, adjusting the degree of orientation through processes such as temperature and stretch ratio to obtain high thermal shrinkage has great instability

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