Polythene packaging film for soymilk

Abstract

A packing film of polyvinyl soymilk is prepared by taking HDPE, LLDPE and color mother material as raw materials and extruding. It's cheap, light, convenient and non-toxic. It has uniform thickness, excellent heat-sealing performance and heat resistance and no environmental pollution. It can be used for automatic soft packed canned soymilk.

Description

1. Technical field [0001] The invention belongs to the technical field of plastic processing, in particular to a high-temperature-resistant cooking and sterilization soybean milk packaging film, which is suitable for filling soybean milk in a fully automatic soft packaging machine. 2. Background technology [0002] Polyethylene resin (PE) is currently the most used resin in the flexible plastic packaging industry. It is non-toxic, tasteless, transparent, easy to process and form, and has good moisture resistance. Therefore, it is widely used in flexible plastic packaging. According to its density, polyethylene can be divided into low-density polyethylene (LDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), and linear low-density polyethylene (LLDPE). Different types of PE packaging films have different properties. Its main performance is shown in the table below: [0003] At present, LDPE film is widely used in the market, which is widely used fo...

AI Technical Summary

Problems solved by technology

Since soy milk packaging has higher requirements on the shelf life than other general liquid food packaging, this high-protein liquid food needs to be sterilized at a high temperature of 120°C to achieve a shelf life of at least two months. The operating temperature of LDPE film does not exceed 100°C. If you use this ordinary LDPE film to package soybean milk for sterilization, you can only use pasteurization (80°C). Therefore, this LDPE film cannot meet the needs of high-temperature cooking and sterilization.

[0004] It can be seen from the above table that the maximum use temperature of high-density polyethylene (HDPE) and linear low-density polyethylene (LLDPE) can reach 120°C, which can meet the temperature required for high-temperature cooking and sterilization, but when these two raw materials are used alone to make packaging films, There are also certain limitations. Due to the high mechanical strength of the HDPE film, the high barrier performance to oxygen and water vapor, the softness of the film is slightly poor, mainly due to its low sealing strength, resulting in a high proportion of film bags. Large, so it is not suitable for the production of soy milk packaging film alone

LLDPE film has high toughness, and its transparency, softness, needle resistance, and heat sealability are all good, but its mechanical strength is low, and it is easy to cause package breakage

At the same time, due to the poor processing performance of LLDPE, the melt viscosity is high during film blowing, the internal friction heat is large, the main current of the extruder is large, the head pressure is high, and the extrusion is unstable, resulting in unstable film bubbles, which increases the film thickness tolerance. , Poor plasticization of LLDPE will also make the slipperiness of the film worse. The soy milk filling machine has higher requirements on the slipperiness of the film.

Therefore, LLDPE is not suitable for the production of soy milk packaging film alone

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