Manufacturing method for super-barrier hollow container

Abstract

The invention discloses a manufacturing method for a super-barrier multilayer hollow container. The manufacturing method comprises the working procedures that one-time blow forming is conducted, specifically, a pre-forming blank made of a resin material is formed in an extrusion blow die, nitrogen is blown into the pre-forming blank under the first air pressure P1, and thus a hollow blank with thefirst volume is formed; mixing blow forming is conducted, specifically, the air pressure is decreased to the second air pressure P2, fluorine is blown into the hollow blank under the third air pressure P3, and thus a hollow blank with the second volume is formed, wherein P3 is larger than P1; and circulation blow forming is conducted, specifically, the air pressure is decreased to the fourth airpressure P4, nitrogen is blown into the hollow blank under the fifth air pressure P5, wherein P5 is smaller than P3, the working procedure is repeatedly cycled till the blow time is finished and the hollow container with the predetermined shape is formed, and at least part of the outer wall of the hollow container is attached to the die cavity wall of the extrusion blow die. The produced hollow container can be higher in barrier property, the application range of the hollow container is enlarged, and the economic benefits are greatly increased while the production efficiency is improved.

Description

technical field [0001] The invention relates to a method for manufacturing a super-barrier multilayer hollow container. Background technique [0002] Common carbonated beverage bottles, coffee beverage bottles, and mineral water bottles in daily life are all made of plastic hollow containers. With the wide application of plastic parts, people have higher and higher requirements for plastic surface properties. In the prior art, plastic hollow containers are obtained by multi-layer co-extrusion-post-line fluorination process. First, different resin polymers that are insoluble in common solvents are used to make them through a multi-layer co-extrusion production process. Among them, resin polymerization Materials include basic raw materials composed of polyethylene (referred to as "PE") and polyethylene terephthalate (referred to as "PET"), and nylon (referred to as "PA") and polyvinyl alcohol (referred to as "EVON") ), the hollow container usually extruded and blown by an ext...

AI Technical Summary

Problems solved by technology

In the prior art, plastic hollow containers are obtained by multi-layer co-extrusion-post-line fluorination process. First, different resin polymers that are insoluble in common solvents are used to make them through a multi-layer co-extrusion production process. Among them, resin polymerization Materials include basic raw materials composed of polyethylene (referred to as "PE") and polyethylene terephthalate (referred to as "PET"), and nylon (referred to as "PA") and polyvinyl alcohol (referred to as "EVON") ), the hollow container usually extruded and blown by an extruder needs to co-extrude at least 3 or 4 layers, and the barrier material is used on the innermost base layer to make the hollow container have better barrier properties, but Due to the small number of co-extruded layers, the impact resistance of the container itself is low, and its drop function is difficult to pass, and because the resin polymer is soluble in some organic solvents, the barrier properties of the container base layer to some organic solvents are poor; further , It is also possible to co-extrude more than 5 layers and use barrier materials in the middle layer. However, because the barrier layer is in the middle layer, the base layer will cause degradation reactions when exposed to some organic solvents, destroying the container itself and shortening the service life of the container, resulting in The waste of resources limits its scope of use; secondly, treating the plastic surface with fluorine gas can make up for the lack of barrier properties of the produced hollow containers. The container is stored in a closed space filled with a certain proportion of nitrogen and fluorine mixed gas for a period of time. The side wall of the container forms a fluorinated layer mainly composed of polytetrafluoroethylene, which can minimize solvent penetration and effectively block organic solvents. , but this post-line fluorination technology requires the use of high-concentration fluorine gas and nitrogen gas in a closed environment with high safety, which not only prolongs the production cycle, reduces production efficiency, but also increases the cost of raw materials, processing and processing. The cost of equipment maintenance greatly reduces the economic benefits