Bottle Preform Moisture Conditioning for Reproducible Crystallization
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Solution Overview
Problem
Existing methods for manufacturing aerosol bottles from thermoplastic materials fail to consistently achieve the desired mechanical characteristics, particularly for bottles containing liquefied propellant gases, due to inconsistent crystallization processes.
Innovation Solution
A method involving moisture uptake of injection-molded articles, specifically preforms, to a weight percentage of at least 0.4% before crystallization, followed by controlled heating and cooling to achieve a crystallinity gradient, enhancing thermal conductivity and mechanical strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If heat treatment is applied to crystallize the neck part of the preform, then mechanical strength is improved, but the crystallization process is not reproducible and desired mechanical characteristics are not consistently achieved
Solution Approach 1:
The preform is pre-conditioned by controlling moisture content before the crystallization heat treatment. This preliminary action ensures that the material is in the optimal state to receive the heat treatment, making the subsequent crystallization process reproducible and reliable.
Solution Approach 2:
The invention changes the physical-chemical parameters of the polymer material by controlling moisture content (0.5-5% by weight) before heat treatment. This parameter adjustment enables reproducible crystallization and consistent mechanical properties.
2Weight of moving object
If the preform is made lighter through crystallization, then weight is reduced, but the crystallization process must be precisely controlled to achieve consistent results
Solution Approach 1:
Moisture content is controlled in advance before crystallization, preparing the material to achieve consistent crystallization results with reduced weight and improved mechanical properties.
Solution Approach 2:
By adjusting the moisture content parameter to specific ranges (0.5-5% by weight), the crystallization process becomes more controllable and reproducible, enabling consistent lightweight bottle production.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method ensures reproducible and improved mechanical properties, allowing aerosol bottles to withstand high pressures and temperatures, ensuring safety and performance.
Implementation Method 1
the injection-molded article, in particular the injection-molded preform, is held for a sufficient duration under storage conditions such that it undergoes moisture uptake of at least 0.4%, better still at least 0.8%, and even better still at least 1%, by weight
Implementation Method 2
The invention is based on the finding that such moisture uptake makes it possible to improve the thermal conductivity of the material of the article
Implementation Method 3
crystallizing said part of the injection-molded article, in particular of the injection-molded preform, by heating and then cooling the latter
Implementation Method 4
the plastic material is subjected to a crystallizing heat treatment in the region of said neck
Implementation Method 5
the heat treatment, which is effected for example with the aid of lamps emitting infrared radiation
Implementation Method 6
lamps emitting infrared radiation
Data Source
AI summary
A method for manufacturing an injection-molded article, preferably a preform (11) of a bottle (1), in particular an aerosol bottle, made of a crystallizable polymer material, this article having at least one crystallized part (3), in particular a neck, and preferably a tubular body (14) closed at one end (16), the method comprising the following steps: a) producing an injection-molded article, preferably an injection-molded preform (11), by injecting the crystallizable polymer into a mold, b) crystallizing said part (3) of the injection-molded article, in particular of the injection-molded preform, by heating and then cooling the latter, wherein, in said method, between step a) and step b), the injection-molded article, in particular the injection-molded preform (11), is held for a sufficient duration under storage conditions such that it undergoes moisture uptake of at least 0.4% by weight.