Polyolefin bidirectional stretching film and preparation method thereof

Abstract

The invention discloses a polyolefin bidirectional stretching film and a preparation method thereof, wherein the polyolefin bidirectional stretching film comprises five layers of layered structures including an upper surface layer, three core layers and a lower surface layer in sequential distribution, wherein the upper surface layer and the lower surface layer are prepared from the following ingredients including 50 to 80 parts of propylene copolymers, 20 to 40 parts of alkylene elastomers, 1 to 6 parts of anti-adhesion agents and 1 to 4 parts of slipping agents; each of the three core layers is prepared from the following ingredients including 69 to 100 parts of ultra-low density polyethylene, 0.1 to 30 parts of vinyl copolymers and 0.01 to 1 part of slipping agents. The technical scheme provided by the invention has the advantages of low hot sealing temperature, wide hot sealing temperature range, soft product hand feeling and high flexibility; the shrinkage effect and the hot sealing performance of the film can be obviously improved; the product performance is improved.

Description

technical field [0001] The invention relates to the technical field of polymer materials, in particular to a polyolefin biaxially stretched film and a preparation method thereof. Background technique [0002] Polyolefin heat-shrinkable film (POF) is generally made of PP and PE co-extruded compound, which contains the advantages of polyethylene and polypropylene, and its performance is better than polyethylene film and polypropylene film, such as high transparency, low temperature resistance , high strength, comprehensive performance of rubbing resistance. POF films are widely used in industrial and retail industries for bundling and packaging applications of various products such as food, cosmetics, pharmaceuticals, and electronics. POF film generally has a 3-5 layer co-extrusion structure, and the biaxial stretching process mainly consists of the following processes: batching and mixing, extruding from an extruder, extruding through a co-extrusion die to form a tube blan...

AI Technical Summary

Problems solved by technology

At present, the thermal shrinkage of polyolefin heat-shrinkable films is mostly between 9% and 45%. For example, the patent of CN200610087005.8 discloses a method for making a low-temperature high-shrinkage polyolefin heat-shrinkable film, which is made of copolymerized polypropylene and The anti-adhesion masterbatch is used as the surface material, and the POF film is obtained by using modified polyethylene, linear low-density polyethylene, etc. as the core material, which can obtain a heat shrinkage rate of 9-36% at a temperature of 80-100 ° C; and For example, the patent of CN201210570489.7 obtains a lower-temperature high-shrinkage film by adding polycis-1,4-isoprene to the upper and lower surface materials, which can A heat shrinkage rate of 35-45% is obtained. The film made by the above method is easy to increase the energy loss of the material used during transportation or on products with higher temperature requirements, and increase the defect rate in the product packaging process.

Images