Pouch Forming Die Bead Geometry for Corner Wrinkle Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional pouch forming devices experience wrinkles and/or breakage at the corners where the long and short sides of the pouch sheet intersect during the formation of the cup portion due to uneven inflow volume.
Innovation Solution
A pouch forming device with a die structure featuring curved beads on the flat portion, where the shortest distance between the bead and the long side is closest at the middle and farthest at the ends, and symmetrical sub-beads on the second region to control the inflow volume, particularly near the corners, thereby reducing the difference in inflow volume between the corner and middle regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If straight beads are formed on the flat portion to prevent pouch sheet slippage, then the pouch sheet is securely fixed, but wrinkles and breakage occur at the corners due to uneven inflow volume
Solution Approach 1:
The bead shape is modified to have different radii of curvature at different locations: a first radius of curvature at the middle portion and a second radius of curvature (smaller than the first) at the end portions. This local variation in bead geometry creates corresponding variations in the distance between the bead and the nest, allowing different regions to control material flow differently - the middle region prevents slippage while the corner regions with larger distances allow greater material inflow, preventing wrinkles and breakage
Solution Approach 2:
The bead is designed with curved surfaces characterized by specific radii of curvature rather than straight edges. The first radius of curvature at the middle portion provides smooth contact for fixation, while the second, smaller radius of curvature at the end portions creates a gradual transition that increases the distance to the nest at corners, enabling controlled material flow and preventing surface defects
2Quantity of substance
If the bead distance to the nest is reduced to increase inflow volume, then material flow improves, but the pouch sheet cannot be securely fixed
Solution Approach 1:
The bead geometry is designed with spatially varying curvature radii that create corresponding spatial variations in the distance to the nest. The middle portion maintains a smaller distance for secure fixation, while the end portions have larger distances to increase inflow volume at corners, achieving both fixation reliability and sufficient material flow simultaneously
Data Source
Figure 1A
Figure 1B
Figure 1C
AI summary
The present disclosure relates to a pouch forming device that forms a cup portion in a pouch sheet and the pouch forming device includes a die having a concavely recessed nest formed on an upper surface and a flat portion formed along the perimeter of the nest; a stripper pressing and fixing a portion of the pouch sheet placed on the flat portion when the pouch sheet is seated on the die; and a punch pressing the pouch sheet to enter the nest and forming a cup portion in the pouch sheet, wherein a bead is formed by protruding from the surface of the flat portion, and the bead is formed to form a curved shape on the flat portion.