Tampon Overwrap Sealing with Heated Concave Jaws
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Solution Overview
Problem
Existing methods for overwrapping catamenial tampons with apertured films face challenges in heat sealing without melting the film, especially due to the geometry of the insertion end, which can result in the film adhering to the overwrap.
Innovation Solution
A process involving a cylindrical overwrapper with heated concave clamping jaws that seal the overwrap at the withdrawal end and mold it to form radial sections, allowing the overwrap to conform to the domed insertion end without excessive heat transfer, using fewer and more uniform layers to reduce material waste and thermal damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If heat is supplied to seal the overwrap at the insertion end, then the overwrap is sealed, but the apertured film covering the insertion portion melts and adheres to the overwrap
Solution Approach 1:
The patent applies different thermal properties to different regions of the tampon structure. The apertured film covering the insertion portion is made of material with a melting point at least 10°C lower than the overwrap material, creating a localized thermal gradient that protects the film from melting during overwrap sealing. This local differentiation in material properties allows the overwrap to be sealed at temperatures that do not affect the apertured film.
Solution Approach 2:
The patent introduces an intermediary thermal barrier concept by using the apertured film itself as a protective layer. The film's lower melting point material acts as a thermal buffer, absorbing excess heat and preventing direct heat transfer to the overwrap-sealed region. This intermediary layer protects the apertured film from adhering to the overwrap during the sealing process.
2Reliability
If conventional heat sealing is used at the insertion end, then sealing is achieved, but material waste increases due to excessive layers and melting
Solution Approach 1:
The patent changes the thermal parameters of the system by using materials with different melting points. The apertured film uses material with a melting point at least 10°C lower than the overwrap, allowing sealing to be performed at temperatures below the film's melting point. This parameter change enables effective sealing while preventing material degradation and waste.
Solution Approach 2:
The patent segments the tampon structure into distinct thermal zones: the apertured film covering the insertion portion with lower melting point material, and the overwrap with higher melting point material. This segmentation allows independent thermal management of each layer, enabling the overwrap to be sealed without affecting the apertured film, thereby reducing material waste.
3Manufacturing precision
If the overwrap is tightly sealed to conform to the domed insertion end, then sealing effectiveness improves, but the apertured film may adhere to the overwrap
Solution Approach 1:
The patent applies local quality differentiation by using apertured film material with a melting point at least 10°C lower than the overwrap material at the insertion end. This localized material property difference allows the overwrap to conform tightly to the domed insertion end and seal effectively without the film adhering to the overwrap, as the temperature required for tight sealing would melt the lower-melting-point film material first, creating a protective effect.
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 method effectively seals the overwrap without adhering it to the tampon, reducing material usage by 40% and lowering the required temperature and contact time, ensuring a secure and clean seal while preserving the tampon's integrity.
Implementation Method 1
contacting the extending overwrapper at the domed insertion end with at least three concave clamping jaws, each clamping jaw heated to a temperature
Implementation Method 2
The heat sealing of the overwrap generally occurs at the insertion end and withdrawal end. When heat is supplied to the overwrap material
Data Source
AI summary
A process for overwrapping a catamenial device such as a tampon includes the steps of providing a substantially cylindrical overwrapper material, inserting a catamenial device into the overwrap material, and closing the open end of the overwrapper material. The overwrapper material has an open end, a closed end, and a first length. The catamenial device has a tapered insertion end, a longitudinal axis, and a length less than the first length, such that the open end of the overwrapper material extends beyond the insertion end of the inserted catamenial device. Concave clamping jaws are applied to the open end of the overwrapper material to urge it toward the longitudinal axis of the catamenial device; to conform portions of the overwrapper material to the insertion end of the catamenial device; and to fold overwrapper material between adjacent clamping jaws to form fins extending outwardly from the conformed portions.