Inner Bag Detachment in Rigid Outer Containers
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Solution Overview
Problem
The existing containers with a rigid outer container and an easily deformable inner bag face issues with uncontrolled detachment and potential leakage due to high adhesive forces between different thermoplastic materials, leading to incomplete dispensing and permanent deformation of the inner bag.
Innovation Solution
Incorporating microbodies, such as glass spheres, into the layers of the inner bag or outer container to reduce adhesive forces, allowing for even detachment and reattachment without significant negative pressure, thereby preventing leakage and deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If different thermoplastic materials are used for the outer container and inner bag, then the container structure is formed, but high adhesive forces cause uncontrolled detachment and potential leakage
Solution Approach 1:
The patent applies a release agent locally at the interface between the inner bag and outer container to modify adhesion properties only where needed. This allows the inner bag to detach cleanly from the outer container wall during filling while maintaining structural integrity elsewhere. The release agent creates a localized low-adhesion zone that enables controlled separation without affecting the overall container structure.
Solution Approach 2:
The release agent acts as an intermediary substance between the inner bag and outer container materials. It mediates the interaction by reducing adhesive forces at the interface, allowing the inner bag to detach controllably during the filling process. This intermediary layer prevents direct contact between the thermoplastic materials, eliminating uncontrolled detachment and leakage risks.
2Ease of operation
If a large vacuum is applied to detach the inner bag, then separation is achieved, but permanent deformation and folds occur in the inner bag
Solution Approach 1:
The release agent creates a localized low-adhesion interface between the inner bag and outer container. This localized modification allows the inner bag to detach with minimal vacuum pressure, preventing the high vacuum levels that would cause permanent deformation and folds. The detachment occurs smoothly at the interface without creating stress concentrations that could deform the bag structure.
3Productivity
If the inner bag is not evenly detached from the outer container, then incomplete dispensing occurs, but high negative pressure causes leakage through the inner bag wall
Solution Approach 1:
The release agent as an intermediary substance ensures uniform detachment of the inner bag from the outer container wall. By reducing adhesion forces evenly across the interface, it prevents localized sticking that would cause uneven detachment. This uniform separation allows complete dispensing of contents while maintaining even pressure distribution, preventing leakage through the inner bag wall.
Solution Approach 2:
The release agent modifies the adhesion parameter at the interface between inner bag and outer container. By changing this parameter from high adhesion to low adhesion, the system enables controlled, uniform detachment. This parameter change ensures that the inner bag separates evenly during filling, preventing both incomplete dispensing and leakage caused by uneven detachment and high negative pressure.
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 use of microbodies significantly reduces the vacuum required for detachment, ensuring complete and even separation of the inner bag from the outer container, preventing leakage and maintaining the inner bag's shape during filling and dispensing.
Implementation Method 1
the adhesive forces between this layer and the adjacent inner wall of the outer container or outer wall of the inner bag are significantly reduced
Implementation Method 2
The preform is then inflated by a pressure medium to rest against the wall of the blow mold
Implementation Method 3
a negative pressure is applied through the container opening or an overpressure through pressure equalization openings on the inner bag
Data Source
AI summary
The container, consisting of a substantially rigid outer container and a slightly deformable inner bag, wherein the outer container and the inner bag are made of different thermoplastic materials and do not form a welded connection with each other, with a container opening and at least one pressure equalization opening in the wall of the outer container for pressure equalization in the space between the outer container and the inner bag when the inner bag contracts, is characterized in that microbodies made of a material that does not melt during the manufacture of the container are integrated in the layer of the inner bag facing the outer container and/or in the layer of the outer container facing the inner bag, creating irregularities on the surface of the layer.