Pouch Molding Blank Holder for Uniform Film Elongation
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Solution Overview
Problem
The existing pouch molding methods for secondary batteries result in non-uniform elongation of pouch films, leading to wrinkles and uneven thickness in the cup part, which affects the cosmetic appearance and longevity of the battery pouches.
Innovation Solution
A pouch molding method and apparatus where a Blank holder and punch move together to uniformly disperse elongation force on the pouch film, ensuring uniform thickness and preventing wrinkles, with adjustable Blank holder movement for easy depth adjustment of the cup part.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If drawing molding is performed by inserting the pouch film into a press and elongating the pouch film using a punch, then the cup part is formed, but the elongation force is not uniform causing wrinkles on the cup part and deteriorating cosmetic appearance
Solution Approach 1:
A blank holder is introduced as an intermediary component between the punch and the pouch film. The blank holder applies uniform pressure to the pouch film during the elongation process, ensuring even distribution of elongation force and preventing wrinkles from forming on the cup part.
Solution Approach 2:
The process parameters are changed by controlling the movement of the blank holder to ascend simultaneously with the punch during elongation. This coordinated movement ensures uniform pressure distribution and consistent elongation across the pouch film, eliminating the non-uniform force application that causes wrinkles.
2Manufacturing precision
If the cup part is formed by inserting the pouch film into an open part formed in a center of a die, then the cup part is formed, but the thickness of the pouch is not uniform due to occurrence of wrinkles and a thin and weak portion may occur to shorten lifetime
Solution Approach 1:
The blank holder serves as a mediator that distributes pressure uniformly across the pouch film during forming. This prevents localized thinning and weak portion formation, ensuring consistent thickness throughout the cup part and maintaining the pouch's structural integrity and lifetime.
Solution Approach 2:
By controlling the blank holder to ascend simultaneously with the punch, the pressure distribution parameter is optimized. This ensures uniform elongation and consistent thickness throughout the pouch, preventing the formation of thin and weak portions that would compromise reliability.
3Adaptability or versatility
If the pouch molding apparatus is disassembled to allow a user to directly changes a position of a Blank holder formed inside the open part, then the depth of the cup part can be adjusted, but the device complexity increases
Solution Approach 1:
The blank holder is designed with dynamic positioning capability, allowing it to ascend and descend simultaneously with the punch during the molding process. This dynamic adjustment enables cup part depth variation without requiring apparatus disassembly, maintaining simplicity while providing adaptability.
Solution Approach 2:
The blank holder's position is pre-configured to move in coordination with the punch before the molding process begins. This preliminary setup allows for easy depth adjustment through simple position changes rather than complex disassembly and reassembly operations.
Data Source
AI summary
To solve the above problems, a pouch molding method according to an embodiment of the present invention includes: a seating step of seating a pouch film on a top surface of a die; a stripper descending step of allowing a stripper disposed above the die to descend; a fixing step of fixing the pouch film using the stripper; a molding preparation step of allowing a Blank holder disposed at a central portion of the die to ascend to contact one surface of the pouch film and allowing a punch disposed at a central portion of the stripper to descend to contact the other surface of the pouch film; and a molding step of allowing the punch and the Blank holder to descend along with each other to form a cup part in the pouch film.