Dry Cellulose Moulding With Movable Undercuts and Force Control
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Solution Overview
Problem
Existing dry-forming techniques for manufacturing rigid cellulose products with non-flat shapes and undercut features face challenges in controlling press forces, leading to inconsistent product quality, material degradation, and inefficient production processes.
Innovation Solution
A product forming unit with a female mould part featuring displaceable undercut members and an ejector member, controlled by an activation body, ensures precise application of axial and radial pressures in a single pressing operation, allowing for accurate formation and reliable removal of cellulose products without damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If wet-forming techniques are used to manufacture rigid cellulose products with undercut features, then the ability to form undercut features is improved, but the production speed and energy efficiency deteriorate due to drying requirements
Solution Approach 1:
The invention changes the moisture parameter of the cellulose material from wet to dry state, eliminating the drying step while maintaining the ability to form undercut features through the displaceable undercut members in the mould tool
Solution Approach 2:
The invention extracts and removes the drying step from the manufacturing process by using dry cellulose material, thereby eliminating the time-consuming and energy-intensive drying operation while still achieving the desired undercut features
2Productivity
If dry-forming techniques are used to manufacture rigid cellulose products, then the production speed and energy efficiency are improved, but the ability to form undercut features and control press forces deteriorates
Solution Approach 1:
The invention introduces displaceable undercut members that can move between retracted and extended positions, allowing dynamic control of the mould cavity shape during pressing to form undercut features in dry cellulose material
Solution Approach 2:
The invention divides the mould tool into separate displaceable undercut members that can independently control different sections of the product, enabling precise formation of undercut features while maintaining dry-forming efficiency
3Shape
If displaceable undercut members are used to form undercut features, then the shape control is improved, but the device complexity increases
Solution Approach 1:
The mould tool incorporates displaceable undercut members that can move between retracted and extended positions, allowing dynamic control of the mould cavity shape during pressing to form undercut features
Solution Approach 2:
The mould tool is divided into separate displaceable undercut members that can independently control different sections of the product, enabling precise formation of undercut features
4Productivity
If press forces are not precisely controlled during dry-forming, then the production speed is maintained, but the manufacturing precision and product quality deteriorate
Solution Approach 1:
The pressing mechanism incorporates force control that applies predetermined pressure to the cellulose material, ensuring consistent press forces are maintained during the forming process to achieve uniform product quality
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 provides time and energy-efficient production of cellulose products with uniform quality, ensuring consistent press forces and minimizing material damage during removal, thereby improving production efficiency and product integrity.
Implementation Method 1
press the cellulose blank therebetween into final shape by applying a predetermined pressure P in the axial direction
Implementation Method 2
the cellulose fibres are bonded to each other using heat and pressure
Implementation Method 3
ejector member configured for removing the pressed cellulose product from the male mould part
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
The present invention relates to a method and a product forming unit for dry manufacturing rigid cellulose products having essentially non-flat general shape from a cellulose blank (10). The product forming unit comprising a moulding tool having a male mould part (16) and a female mould part (15) having co-operating designs, wherein at least one of the male mould part (16) and the female mould part (15) is displaceable in an axial direction in relation to the other in order to press the cellulose blank (10) therebetween into final shape by applying a predetermined pressure P in the axial direction of the moulding tool. The female mould part (15) comprises a plurality of undercut members (30) displaceable between a retracted position and an inwardly extended position in relation to the inclined wall surface (25) of the female mould part (15), wherein each undercut member (30) is displaceable in a direction that is essentially perpendicular to the inclined wall surface (25) of the female mould part (15), and the moulding tool comprises an undercut member activation body (32) that is displaceable in relation to the female mould part (15) in the axial direction when the male mould part (16) and the female mould part (15) are in the press-position, and thereby configured to displace each undercut member (30) from its retracted position to the inwardly extended position when the male mould part (16) and the female mould part (15) are in the press-position.