Paper Container Moulding with Inverted Curled Edge
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Solution Overview
Problem
Existing methods for moulding paper material containers with a flat perimeter and curled edge are inefficient, as the curled edge interferes with lid application, and prior solutions for metal containers are not applicable due to the malleability differences between paper and metal.
Innovation Solution
An apparatus with stationary and movable die halves, equipped with cutting, pleating, and curling members, forms a curled edge below the flat perimeter portion, allowing for seamless lid application by positioning the curled edge under the flat portion, ensuring accessibility for sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the curled edge is positioned above the flat perimeter portion to provide reinforcement, then the container resistance against bulging is improved, but the accessibility for lid application is worsened
Solution Approach 1:
The patent inverts the conventional arrangement by positioning the curled edge below the flat perimeter portion instead of above it. This inversion allows the flat perimeter to remain accessible for lid application while the curled edge provides reinforcement from underneath, resolving the contradiction between strength and ease of operation.
Solution Approach 2:
The patent utilizes the vertical dimension by placing the curled edge in the lower spatial region beneath the flat perimeter, rather than in the same horizontal plane. This dimensional arrangement allows both the reinforced structure and the accessible flat surface to coexist without interference.
2Strength
If the curled edge is positioned above the flat perimeter portion, then the container structural reinforcement is improved, but the sealing efficiency is worsened
Solution Approach 1:
By inverting the position of the curled edge to below the flat perimeter, the patent ensures that the sealing surface remains unobstructed and accessible, thereby improving sealing efficiency while maintaining structural reinforcement through the underlying curled edge.
Solution Approach 2:
The patent employs vertical spatial separation, positioning the curled edge in the lower dimension beneath the flat perimeter. This dimensional arrangement allows the sealing operation to proceed efficiently on the accessible flat surface while the curled edge provides structural support from below.
3Productivity
If metal container moulding techniques are used for paper material, then the production efficiency is improved, but the material integrity is worsened due to malleability differences
Solution Approach 1:
The patent modifies the moulding parameters and tooling design to accommodate the lower malleability of paper material compared to metal. By adjusting the forming forces, heating conditions, and die design, the patent achieves efficient production while preserving the integrity of the paper container walls and preventing excessive deformation or tearing.
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 solution enables the production of environmentally friendly paper/cardboard containers with a flat perimeter for lid coupling and a reinforcement curled edge, improving sealing efficiency and reducing deformation, thus overcoming the limitations of previous technologies.
Implementation Method 1
The two die halves, i.e. the stationary die half and the mobile die half, cooperate to define an impression corresponding to a container
Implementation Method 2
forms a curled edge below the flat perimeter portion
Implementation Method 3
a curling member and a counter curling member which are operatively associated with the cutting blade, the permanent pleating / wrinkling ring and the curling member of the upper die half, respectively, are concentrically provided around the lower die half
Data Source
Figure 1A~1B
Figure 2A~2C
Figure 3A~3C
AI summary
The invention relates to an apparatus (10) and method for moulding food-grade containers (100) from a strip (C) of paper material. The apparatus comprises a stationary die-holder plate (11), and a die- holder plate (12) which is movable with respect to it between an opened position and a closed position. The stationary die-holder plate comprises a respective stationary die half (14) and the movable die-holder plate comprises a respective mobile die half (15). In the closed position, the two die halves (14, 15) cooperate to define an impression corresponding to a container (100)provided with a bottom (101), a side wall (102), and a substantially flat perimeter portion (103) cantileverly extending from the side wall. A curling member (20), a permanent pleating member (19) and a cutting blade (18) are concentrically provided around the mobile die half and sequentially arranged from the inside to the outside thereof. Similarly, a counter curling member (23), a counter permanent pleating member (22) and a counter cutting blade (21) are concentrically arranged around the stationary die half. The blade and the counter cutting blade interact to cut a blank (C')from the starting strip, the dimensions of the blank being proportional to the dimensions of the container to be moulded. The permanent pleating member and the counter permanent pleating member interact to permanent pleat or wrinkle a peripheral crown (CI) of the blank at least at a portion of the side wall. The curling member and the counter curling member interact to form a curled edge extending externally from the peripheral flat portion of the container being moulded. Advantageously, the mobile die half can be at least partially inserted into the counter curling member so as to form the curled edge (104) of the container between the lying plane of the respective flat perimeter portion and the bottom of the container itself.