Bone Cement Transfer Piston for Fast Mixing and Dispensing
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Solution Overview
Problem
Existing mixing equipment is not well-suited for highly viscous bone cements that transition quickly to a solid state, as it lacks sufficient shear force to effectively mix components during the short liquid phase, leading to incomplete mixing and operational challenges.
Innovation Solution
An apparatus with a mixing well and drive mechanism that adjusts shear force by varying surface roughness, distance, and relative velocities of mixing elements, along with a transfer mechanism to facilitate the flow of viscous materials, ensuring complete mixing and efficient transfer of bone cement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional mixing equipment is used for highly viscous bone cement, then the equipment structure is simple and easy to operate, but insufficient shear force is generated leading to incomplete mixing
Solution Approach 1:
The mixing system is segmented into multiple planetary mixing elements (at least two) that orbit around a central mixing element, each performing mixing functions independently. This segmentation allows generation of sufficient shear force through multiple mixing actions while maintaining a relatively simple overall structure
Solution Approach 2:
The mixing elements employ dynamic motion with different rotational speeds and directions - planetary elements orbit the central element while also rotating on their own axes. This dynamic multi-directional mixing generates the required shear force for highly viscous materials without requiring overly complex mechanical structures
2Manufacturing precision
If mixing time is extended to achieve complete mixing of viscous material, then mixing completeness improves, but the working window closes as the material solidifies
Solution Approach 1:
The planetary mixing elements continuously orbit the central mixing element while simultaneously rotating, creating continuous shear force application throughout the mixing process. This continuous effective mixing action achieves complete mixing faster, preserving the working window before solidification
Solution Approach 2:
The mixing elements are designed with specific surface roughness characteristics before mixing begins, creating preliminary shear conditions optimized for highly viscous materials. This preliminary optimization of mixing conditions enables faster achievement of complete mixing within the limited working window
3Manufacturing precision
If shear force is increased to mix highly viscous material effectively, then mixing effectiveness improves, but the risk of premature solidification increases
Solution Approach 1:
Different mixing elements have different surface roughness characteristics - the central mixing element and planetary mixing elements are configured with specific roughness values optimized for their respective roles. This local optimization of surface properties enables effective shear force generation while controlling the mixing process to avoid premature solidification
4Manufacturing precision
If viscous material is transferred after mixing, then complete mixing is achieved, but material remains in the mixing well leading to waste
Solution Approach 1:
A transfer mechanism acts as an intermediary between the mixing well and the dispensing system, efficiently moving the highly viscous mixed material. This intermediary mechanism ensures complete transfer of the viscous material, minimizing residual material in the mixing well and reducing waste
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 apparatus effectively mixes and transfers highly viscous bone cement with viscosities up to 500 Pascal/second, ensuring complete mixing in a short time and providing a longer working window before solidification, addressing the limitations of existing equipment.
Implementation Method 1
Mixing apparatus for high -viscosity mixtures must be adapted to provide sufficient shear force to continue moving against great resistance
Implementation Method 2
When a polymer and monomer are combined, a polymerization reaction begins. The polymerization reaction increases the average polymer chain length in the mixture and/or causes cross-linking between polymer chains. Increased polymer chain length and/or cross linking between polymer chains contribute to increased viscosity
Data Source
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AI summary
An apparatus for transferring a viscous material, the apparatus comprising: a) a first container capable of containing a viscous material; b) a transfer piston insertable in the first container so that the piston forms a circumferential seal with respect to the container, the transfer piston including a hole; and c) a mechanism for attaching an aperture of a second container to the hole in the transfer piston; wherein insertion of the transfer piston into the first container causes the viscous material to pass through the aperture into the second container.