Liquid-Reservoir Casting Mold for Consistent Pulp Walls
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Solution Overview
Problem
Existing methods for producing fiber-based containers from pulp face challenges in controlling and regulating the deposition of pulp, leading to inconsistent wall thicknesses and properties due to variations in the type and amount of pulp, resulting in varying strengths and surfaces.
Innovation Solution
A method involving a casting mold with a liquid reservoir and controlled drainage system, using a process fluid to create a standing column for pulp application, allowing precise control of pulp distribution through overpressure, vacuum, and timed drainage at multiple points to achieve targeted fiber settling and wall construction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If pulp is injected into an upside-down mold using a flexible balloon, then the container can be produced, but the deposition of pulp cannot be controlled and regulated
Solution Approach 1:
The mold is pre-filled with a liquid reservoir (water or other liquid) before pulp injection. This preliminary preparation creates a liquid medium that the pulp must displace, providing a reference level and enabling controlled deposition. The liquid reservoir is prepared in advance to establish the initial conditions for precise pulp placement.
Solution Approach 2:
The invention replaces the flexible balloon mechanical injection system with a gravity-driven pulp suspension flow system. Instead of using mechanical pressure from a balloon to inject pulp, the system uses a pulp suspension that flows under gravity into the mold, displacing the liquid reservoir. This substitution provides better control over deposition rates and patterns.
2Adaptability or versatility
If pulp components vary, then different properties are achieved in the finished container, but wall thickness and strength become inconsistent
Solution Approach 1:
The liquid reservoir acts as a feedback mechanism by providing a visible reference level that indicates how much pulp has been deposited. As pulp enters the mold, it displaces the liquid, and the changing liquid level provides real-time feedback on the deposition process. This allows operators to monitor and control wall thickness consistency despite variations in pulp properties.
Solution Approach 2:
The invention changes the physical state and parameters of the pulp delivery system by using a liquid suspension medium instead of direct pulp injection. The pulp is delivered as a suspension that flows smoothly and can be controlled by adjusting suspension concentration, flow rate, and viscosity parameters, enabling consistent deposition even when pulp component variations occur.
3Productivity
If pulp is compressed and heated to 180°C, then the container is dried, but surface quality and fiber orientation become variable
Solution Approach 1:
The mold cavity is pre-filled with liquid reservoir before pulp injection, creating a controlled environment for fiber settling. The liquid provides a uniform medium that facilitates even fiber distribution during the initial settling phase before compression and heating, leading to more consistent surface quality and fiber orientation in the final product.
Solution Approach 2:
The liquid reservoir serves as an intermediary medium between the incoming pulp suspension and the mold cavity. It mediates the interaction by providing a uniform liquid environment that promotes even fiber distribution and settling patterns, resulting in more consistent surface quality and fiber orientation after the drying process.
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
Enables precise control of pulp distribution, resulting in consistent wall thickness and optimized fiber-based containers with tailored properties such as weight, stackability, and fiber orientation, overcoming the inconsistencies of conventional methods.
Implementation Method 1
The liquid reservoir provides a standing column that is substantially free of turbulence and/or eddies
Implementation Method 2
The draining process can be controlled by an overpressure that is applied to the pulp
Implementation Method 3
it can be provided to remove the liquid reservoir in the casting mold using a vacuum such that the pulp is sucked into the mold
Implementation Method 4
A casting mold for producing a fiber-based blank is typically permeable to liquid
Data Source
AI summary
A method and a casting mold for producing a fiber-based blank made of pulp (40). The method has the steps of providing a casting mold, filling the casting mold with a process liquid such that a liquid reservoir (31) is formed in the casting mold, and applying pulp (40) onto the liquid reservoir (31) in the casting mold.