Manufacturing method of ultra-barrier hollow container

Abstract

The invention discloses a method for manufacturing a super-barrier multi-layer hollow container, comprising: a blow molding process, in which a preform made of resin material is injected into the preform with a first air pressure P1 Blowing nitrogen to form a hollow body with a first volume; mixing blow molding process, reducing the air pressure to the second air pressure P2, and blowing fluorine gas into the hollow body with a third air pressure P3 to form a hollow body with a second volume. Embryo body, wherein, P3 is greater than P1; cycle blow molding process, reduce the air pressure to the fourth air pressure P4, blow nitrogen into the hollow body with the fifth air pressure P5, wherein, P5 is less than P3, repeat this step until After the blowing time is over, the hollow container of a predetermined shape is formed, and the outer wall of the hollow container is at least partially attached to the cavity wall of the extrusion blow mold. The invention can make the barrier property of the produced hollow container stronger, expand its application range, and greatly improve the economic benefit while improving the production efficiency.

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