Bottle blank structure beneficial to stretch blow molding

Abstract

A bottle blank structure beneficial to stretch blow molding comprises a bottle blank which is integrally formed through injection molding, and the bottle blank comprises a bottle opening, a bottle neck, a blank body and a blank bottom, all of which are sequentially connected. The blank bottom is arranged to be an upper bottom and a lower bottom which are connected, the bottommost end of the lower bottom is lower than a convergent point formed by extension lines of a generatrix curve section I of the upper bottom, so that the lower bottom protruding downwards is formed by the blank bottom on the basis that the upper bottom is formed, the lower bottom serves as a pre-stretching structure of the blank bottom, so that the blank bottom is fully unfolded in the stretch blow molding process, serious material accumulation of the bottle bottom is avoided, more materials are distributed to the remaining parts of the bottom of the bottle blank, and therefore when the bottle blank is designed, the wall thickness of the blank bottom can be designed to be smaller, and the purpose of light weight is achieved.

Description

technical field [0001] The invention relates to the technical field of bottle preform structure, in particular to a bottle preform structure beneficial to stretch blow molding. Background technique [0002] With the improvement of living standards, containers made of glass, ceramics, metals, etc. that were commonly used in the past are gradually being replaced by plastic containers. Compared with containers made of glass, ceramics, and metals, plastic containers are light in weight, not easy to break The advantage of low transportation costs. [0003] Among beverage packaging containers, PET bottles are the most common, and PET bottles have been widely used in various fields of life, such as food, chemical industry, pharmaceuticals, etc., so the demand for PET bottles is very large. According to statistics, the consumption of PET bottles in China in 2018 has exceeded 10 million tons, and the demand is gradually increasing. Therefore, the lightweight of PET bottles is an imp...

AI Technical Summary

Problems solved by technology

Before pre-blowing, the stretching rod will stretch the preform. There is a part of the bottom of the preform that wraps the stretching rod. This part is not easy to be stretched during the blow molding process. When the bottom of the preform reaches the bottom of the mold and touches the mold At the same time, the bottom material of the preform is easy to cool prematurely, which makes it more difficult to stretch the bottom of the preform that has not been fully stretched

All of the above reasons will lead to insufficient stretching of the material at the bottom of the preform, and the bottle formed by stretch blow molding is prone to problems such as excessive material accumulation at the bottom, too thick center point, and easy cracking at the bottom due to stress.

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