Overmolding Rigid Shell Around Flexible Pouch
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Solution Overview
Problem
There is no simple technology for producing a container comprising an internal flexible pocket placed in a rigid external shell, with existing methods either lacking a chemical or physical bond between the pouch and shell or being limited in shape flexibility.
Innovation Solution
A method involving a core with a flexible pocket and a mold to overmold a rigid shell using chemically incompatible plastic materials, allowing the pocket to detach and providing aesthetic flexibility in the shell's shape, with features like retaining appendages and venting passages for secure attachment and air penetration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If welding is used to join the flexible pouch to the rigid pouch support, then the connection strength is improved, but the manufacturing complexity and difficulty increase
Solution Approach 1:
The patent extracts the joining operation entirely by using chemically incompatible materials that naturally prevent bonding. The flexible pouch and rigid shell are placed in direct contact without any joining process, eliminating welding complexity while maintaining functional separation.
Solution Approach 2:
The patent introduces an intermediary detachment layer between the flexible pouch and rigid shell. This layer acts as a mediator that prevents chemical bonding while allowing mechanical function, simplifying the overall manufacturing process by eliminating direct joining requirements.
2Ease of manufacture
If the flexible pouch is placed inside the rigid shell without chemical or physical bond, then the manufacturing simplicity is improved, but the connection reliability deteriorates
Solution Approach 1:
The patent changes the chemical parameters of the materials by selecting chemically incompatible plastics for the pouch and shell. This parameter change ensures no bonding occurs during injection molding, maintaining manufacturing simplicity while providing reliable functional separation through material property control.
Solution Approach 2:
The patent uses composite material selection - combining chemically incompatible plastic materials for the pouch and shell respectively. This material strategy ensures no unwanted bonding while maintaining the structural integrity and reliability of each component independently.
3Ease of manufacture
If the same plastic material is used for both pouch and shell, then the manufacturing process is simplified, but the ability to detach the pouch from the shell deteriorates
Solution Approach 1:
The patent changes the chemical composition parameter by selecting incompatible plastic materials for the pouch and shell. This ensures that during injection molding, the materials do not bond chemically, allowing the pouch to be detached from the shell after dispensing while maintaining a simplified one-step molding process.
4Manufacturing precision
If the rigid shell is made to match the shape of the flexible pouch, then the manufacturing precision is improved, but the aesthetic design flexibility deteriorates
Solution Approach 1:
The patent segments the design requirements by allowing the flexible pouch and rigid shell to have independent shapes. The pouch maintains its functional shape while the shell provides aesthetic design freedom, with the injection molding process accommodating both independent geometries without requiring shape matching.
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
Enables the rapid and simple production of containers with flexible pockets and rigid shells that can be aesthetically designed independently, ensuring the pocket can detach from the shell during use while maintaining mechanical integrity.
Implementation Method 1
The molten plastic material is of course injected under pressure into the injection space so that the flexible pocket tends to be pressed against the core.
Implementation Method 2
the flexible pocket is elastically deformable, so that once engaged around the core, it conforms to the outer wall of the core without forming folds.
Data Source
Figure 1a~1d
Figure 2a~2c
Figure 3a~3c
AI summary
Method of manufacturing a container comprising a flexible pouch (2) and a rigid shell comprising the following steps: – supplying a core (C1) having an external wall (Cw; Cf), – fitting the flexible pouch (2) around the core (C) so that it covers at least part of the external wall (Cw; Cf), – supplying a mould (M1) having an internal wall (Mw; Mf), defining an internal cavity, – arranging the core (C1), with its flexible pouch (2) engaged around it, inside the internal cavity of the mould (M1) so as to define an injection space (E1) between the internal wall (Mw; Mf) of the mould (M1) and the flexible pouch (2; 2'), – injecting a molten plastic into the injection space (E1) so as to form the rigid shell (3) around the flexible pouch (2) while at the same time allowing the flexible pouch (2) to detach itself from the rigid shell (3).