Preform and method of fabrication of a carafe by injection stretch blow-molding
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Solution Overview
Problem
The challenge lies in manufacturing attractive, affordable, recyclable, and safe plastic beverage containers with an oval or bell-shaped neck, which are compatible with the Injection Blow Molding (IBM) method, while ensuring correct orientation and industrial production line efficiency, as existing methods face issues with preform orientation, heating, blowing, filling, sealing, and labeling due to the unique shape.
Innovation Solution
A new carafe design featuring an oval or elliptic neck and body cross-section, with a preform that includes an annular groove for precise handling, and a manufacturing method involving injection molding followed by stretch-blow molding, using thermoplastic polymers like PET, which allows for precise orientation and efficient production, including a blowing process at controlled pressures to maintain shape integrity and facilitate sealing and filling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If an oval or bell-shaped neck design is used to create attractive premium beverage containers, then aesthetic appeal and consumer attraction are improved, but manufacturing complexity and production line efficiency deteriorate due to orientation and handling difficulties
Solution Approach 1:
The patent applies asymmetry by designing the preform with a non-circular cross-section (oval or bell-shaped neck) that is inherently asymmetric. This asymmetric shape is intentionally created during injection molding to achieve the desired aesthetic appeal while establishing unique orientation characteristics that facilitate subsequent handling and processing steps in the production line.
Solution Approach 2:
The patent implements preliminary action by pre-establishing the correct orientation of the asymmetric preform during the injection molding process itself. Features such as non-circular cross-sections and specific geometric configurations are built into the preform before blow molding, so that the preform naturally assumes the correct orientation during transfer and processing, eliminating the need for complex orientation mechanisms later in the production line.
2Shape
If an oval cross-section preform is used to achieve the desired neck shape, then aesthetic quality is improved, but orientation precision and handling reliability deteriorate due to the unique shape
Solution Approach 1:
The asymmetric oval or bell-shaped cross-section serves a dual purpose: it creates the desired aesthetic appearance and simultaneously provides inherent orientation cues. The non-circular geometry ensures that the preform can only be positioned in one correct orientation, making it easy to identify and handle correctly throughout the production process without requiring additional orientation mechanisms.
Solution Approach 2:
While not directly applying color changes, the patent uses geometric variations (analogous to visual differentiation) in the preform shape - specifically the non-circular cross-section and bell-shaped neck features - to provide visual and tactile cues for correct orientation, similar to how color changes provide visual information in other contexts.
3Productivity
If the preform is heated and blown into the mold to form the final container, then production efficiency is improved, but shape integrity and sealing quality deteriorate due to orientation errors
Solution Approach 1:
The correct orientation is predetermined and built into the preform geometry during injection molding. This preliminary action ensures that when the preform is transferred to the blow molding station, it is already in the correct orientation, allowing for rapid processing without compromising shape integrity or sealing quality, thus maintaining high production efficiency.
Solution Approach 2:
The asymmetric geometry of the preform with non-circular cross-section creates a unique orientation signature that ensures proper alignment during the heating and blow molding process. This asymmetric design prevents orientation errors that would otherwise lead to defective products, maintaining both shape integrity and production speed.
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 solution enables the industrial-scale production of high-quality, aesthetically pleasing, and functional plastic beverage containers with oval necks, ensuring proper orientation, sealing, and filling, while maintaining the shape integrity and productivity, thus overcoming previous manufacturing obstacles.
Implementation Method 1
the preforms are heated above their glass transition temperature
Implementation Method 2
the preforms are heated above their glass transition temperature, then blown using high pressure air into bottles
Data Source
Figure 1~4
Figure 1A~2A
Figure 5~6A
AI summary
The invention's purpose is to propose an attractive liquid container, especially beverage container, made by Injection Stretch Blow-Molding (ISBM), of a thermoplastic polymer, preferably PolyEthyleneTerephtalate (PET). Therefore, the invention concerns a carafe (1) made by an Injection Stretch Blow Molding method wherein a preform (lp) in PET, is injected molded in a first mold and is then stretched-blown-molded in a second mold, said carafe (1) comprising from its top, a neck finish (21), a neck (22), a body and a bottom; the neck finish (21), the neck, and possibly the body, of said carafe (1) having an oval, preferably elliptic, cross-section and the largest dimension of the cross section of the neck decreases from the top to the base of the neck (22).