Dosing Bottle Neck Finish Distortion Prevention
Solution Overview
Problem
Existing dosing bottles face challenges in maintaining precise control over the neck finish dimensioning, leading to potential distortion during the blow molding process, which affects the accuracy of metered liquid dispensing, and often employ complex structures that complicate fitment seating.
Innovation Solution
The method involves injection molding a synthetic resin preform with a threaded neck finish and internal collar, using a blow mold with separate elements to prevent distortion, and a cup-shaped fitment with bosses for secure frictional engagement, ensuring the neck finish remains undistorted and the fitment is securely positioned.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If air is introduced under pressure to blow the side walls outwardly during the blow molding process, then the bottle body is formed, but the neck finish becomes distorted
Solution Approach 1:
The blow mold is divided into two separate elements: a first element that forms the bottle body and a second element that forms the neck finish. This segmentation allows the neck finish to be formed separately from the body, preventing distortion caused by blowing pressure while still completing the bottle formation process.
Solution Approach 2:
The neck finish is pre-formed in the injection molded preform with high precision before the blow molding process. The separate second element of the blow mold then simply replicates this pre-formed neck finish without subjecting it to high blowing pressures, thereby preserving the dimensional accuracy established during injection molding.
2Reliability
If complicated structures are used to seat the fitment, then the fitment can be securely positioned, but the assembly process becomes complex
Solution Approach 1:
The fitment seating function is extracted from the blow mold and integrated directly into the bottle structure through the internal collar and shoulder features formed in the neck finish. This eliminates the need for separate complex seating mechanisms in the mold while ensuring reliable fitment positioning through the built-in geometric features.
Solution Approach 2:
The neck finish structure itself provides the seating features for the fitment through the internally threaded collar and shoulder. The structure is self-sufficient and does not require additional external components or complex mechanisms to secure the fitment, thereby simplifying the overall assembly while maintaining reliability.
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
This approach allows for reliable and repeatable dispensing of precise liquid volumes by maintaining the neck finish integrity and simplifying the assembly process, ensuring consistent metered doses without distortion, and accommodating various dosing volumes through interchangeable fitments.
Implementation Method 1
Air is introduced under pressure to cause the side walls to blow outwardly
Implementation Method 2
The mold around the preform neck finish extracts heat from the neck finish of the preform
Implementation Method 3
the fitment is pushed downwardly so that its periphery frictionally engages in the neck finish
Data Source
AI summary
A dosing bottle is made by injection molding a synthetic resin preform with a threaded neck finish portion and a body portion. The neck finish has an internal collar adjacent said lower end thereof. The preform is removed from the injection mold and inserted into the mold of a blow molding machine. The mold has a cavity with a body portion conforming to the desired configuration and dimensions for the body of the bottle and a neck portion closely conforming to the configuration and dimensioning of the neck portion of the preform. The preform is heated and inserted into the blow mold cavity with the neck finish portion of the preform being sealed from the body portion of the cavity. Air is introduced into the body portion of the preform to blow the body portion of the preform into conformity with the body cavity while precluding any distortion of the collar and of the neck finish.