Rotating Mold Centrifugal Shaping for Lightweight Recycled Paper Articles
Solution Overview
Problem
Existing methods for molding three-dimensional objects from recycled paper and wood face challenges in producing lightweight articles and controlling material shrinkage during the drying phase, as they often result in heavy full products and unmanageable shrinkage.
Innovation Solution
A molding process and apparatus that utilize a rotating mold with water and a mixture of paper and/or wood, applying centrifugal force to shape the mixture on the mold walls, allowing for hollow, lightweight three-dimensional articles and controlled drying through regulated water content and heating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If normal molding by inserting pulp in molds is used to produce three-dimensional bodies, then the mold can be completely filled with pulp, but the obtained article becomes a full product with excessive weight
Solution Approach 1:
The invention extracts the harmful element (excess material/weight) by creating a hollow interior within the molded article. The mold is designed with a cavity that prevents material from filling the entire volume, thereby producing a lightweight structure while maintaining the desired external shape and functional integrity.
2Adaptability or versatility
If recycled paper is used to make three-dimensional bodies through complex assembly of printed articles, then various types of items can be produced, but the manufacturing process becomes complex and results are not optimal
Solution Approach 1:
The invention merges multiple operations (molding, shaping, and hollow cavity formation) into a single integrated molding process. By combining these steps, the process eliminates the need for complex assembly operations while maintaining the ability to produce diverse three-dimensional products from recycled paper materials.
3Shape
If the mold is completely filled with pulp to create three-dimensional bodies, then the article achieves full form, but the weight increases significantly
Solution Approach 1:
The invention applies local quality by creating a non-uniform material distribution within the mold cavity. The walls and structural components are filled with pulp to achieve the desired shape and strength, while the interior space is left hollow to reduce material quantity and overall weight, thereby optimizing the local material presence according to functional requirements.
4Ease of manufacture
If material shrinkage during drying is allowed to occur naturally, then the drying process is simple, but the shrinkage is difficult to control
Solution Approach 1:
The invention applies preliminary action by pre-establishing the hollow cavity structure within the mold before the drying process begins. This pre-formed structural framework guides and constrains the drying-induced shrinkage, ensuring that the material contracts in a controlled manner that maintains the desired dimensional accuracy and shape integrity throughout the drying phase.
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 process and apparatus enable the production of lightweight, hollow three-dimensional articles by shaping the mixture on the mold walls and managing shrinkage through controlled drying, resulting in a lighter and more efficient molding outcome.
Implementation Method 1
Due to the centrifugal force, the mixture of paper and/or wood is arranged on the walls of the mold on taking the same shape of the mold
Implementation Method 2
water is added to the mixture of paper and/or wood in the mold
Implementation Method 3
during the rotation of the mold and/or right after, the mixture of water and paper and/or wood is dehydrated
Data Source
Figure 1
Figure 2
AI summary
The present invention refers to a molding process and a molding apparatus for the molding of recycled paper and/or recycled wood that allow to obtain articles of three-dimensional development of low weight.