Injection-Molded Preform Neck Constriction Design
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Solution Overview
Problem
Existing preforms for plastic containers in stretch blow molding processes have optimal material weight, but efforts to reduce material usage are hindered by the need for multiple modifications to stretch blow molding devices and bottling plants, and the neck section's wall thickness contributes significantly to the overall weight.
Innovation Solution
An injection-molded preform with a neck section featuring constrictions that are highly oriented and partially crystalline, achieved through the injection-molding process, allowing for reduced material usage while maintaining mechanical strength, gas-tightness, and thermal stability, with wall thicknesses between 0.4 mm to 0.8 mm, which increases density and stiffness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If the wall thickness of the neck section is reduced to decrease material usage, then material weight is reduced, but mechanical strength and gas-tightness are compromised
Solution Approach 1:
The patent applies local quality by creating constrictions with varying wall thicknesses in the neck section. Specifically, the neck piece has a first constriction with wall thickness of 0.9-2.0 mm and a second constriction with wall thickness of 0.4-0.8 mm. This localized variation in wall thickness allows material reduction in specific areas while maintaining sufficient strength where needed, resolving the contradiction between material usage reduction and mechanical strength preservation.
Solution Approach 2:
The patent changes the physical parameters of the neck section by introducing constrictions with specific wall thickness ranges (0.4-0.8 mm and 0.9-2.0 mm) and creating a highly oriented, partially crystalline structure through injection molding. These parameter changes enable the neck section to achieve both reduced material usage and maintained mechanical properties through optimized structural characteristics rather than uniform thickness.
2Loss of substance
If the wall thickness of the neck section is reduced to decrease material usage, then material weight is reduced, but gas-tightness is compromised
Solution Approach 1:
The patent applies local quality by creating constrictions with varying wall thicknesses in the neck section. Specifically, the neck piece has a first constriction with wall thickness of 0.9-2.0 mm and a second constriction with wall thickness of 0.4-0.8 mm. This localized variation in wall thickness allows material reduction in specific areas while maintaining sufficient strength where needed, resolving the contradiction between material usage reduction and mechanical strength preservation.
Solution Approach 2:
The patent changes the physical parameters of the neck section by introducing constrictions with specific wall thickness ranges (0.4-0.8 mm and 0.9-2.0 mm) and creating a highly oriented, partially crystalline structure through injection molding. These parameter changes enable the neck section to achieve both reduced material usage and maintained mechanical properties through optimized structural characteristics rather than uniform thickness.
3Loss of substance
If material weight is reduced to improve competitiveness and environmental balance, then material savings are achieved, but multiple modifications to stretch blow molding devices and bottling plants are required
Solution Approach 1:
The patent applies preliminary action by creating the highly oriented, partially crystalline structure and optimized constriction geometry during the injection molding process itself. This preliminary structuring of the preform ensures that subsequent stretch blow molding can proceed on existing equipment without modifications, as the preform is pre-conditioned to achieve the desired final product properties through the injection molding parameters rather than requiring equipment changes.
Solution Approach 2:
The patent changes the physical parameters of the neck section by introducing constrictions with specific wall thickness ranges (0.4-0.8 mm and 0.9-2.0 mm) and creating a highly oriented, partially crystalline structure through injection molding. These parameter changes enable the neck section to achieve both reduced material usage and maintained mechanical properties through optimized structural characteristics rather than uniform thickness.
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 preform achieves reduced material usage without compromising mechanical or thermal properties, allowing for mass production on existing devices and ensuring the preforms can be processed without modifications, leading to significant material savings and improved manufacturing efficiency.
Implementation Method 1
the injection-molded plastic material exists on the at least one constriction in a state that is highly oriented and at least partially crystalline, due to an injection-molding process
Data Source
AI summary
An injection-molded preform for manufacturing plastic containers, for example plastic bottles, in a stretch blow molding process is disclosed. The preform can have an essentially elongated preform body, whose one longitudinal end is formed closed. On an opposite longitudinal end, the preform body is connected to a neck section that is provided with a pour opening and whose outer wall has a connector to make an interlocking connection with a closure that is equipped with corresponding engagement. The neck section has at least one constriction that extends all the way around and has a wall thickness of between 0.4 mm and 0.8 mm. The injection-molded plastic material exists at least on the at least one constriction in a state that is highly oriented and at least partially crystalline, due to an injection-molding process.