Urea Grease Shear Mixing for Lump-Free Structure
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Solution Overview
Problem
Urea greases with excellent heat resistance and acoustic characteristics often form lumps during manufacturing, which are visible under an optical electron microscope, making them unsuitable for applications requiring both properties.
Innovation Solution
A method involving a shear rate of 10^3 s^-1 or more is applied to a mixture of alicyclic monoamine, chain aliphatic monoamine, and diisocyanate compounds during the reaction to produce a urea grease with Peak High32-64s of 1.5 or less and Level High32-64s of 10 or less, preventing lump formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If urea grease is prepared using conventional batch processes with amine components, then heat resistance is improved, but lumps form that are visible under optical electron microscope
Solution Approach 1:
The invention changes the shear rate parameter from conventional low shear rates to a specific high shear rate range of 10^3 s^-1 or more during the reaction process. This parameter change transforms the manufacturing outcome from lump formation to fine, uniform grease structure while preserving heat resistance properties
Solution Approach 2:
The invention applies periodic high shear action during the reaction process to continuously disrupt and redistribute the forming grease structure. This periodic mechanical intervention prevents lump formation by maintaining uniform distribution of thickener throughout the base oil
2Temperature
If conventional urea grease manufacturing is used, then heat resistance is achieved, but acoustic characteristics deteriorate due to lump formation
Solution Approach 1:
By changing the shear rate parameter to 10^3 s^-1 or more, the invention eliminates lumps that cause poor acoustic characteristics. The high shear rate creates a fine, uniform grease structure that improves acoustic performance while maintaining the heat resistance provided by the urea thickener
3Ease of manufacture
If batch process is used to manufacture urea grease, then production simplicity is maintained, but fine uniformity cannot be achieved
Solution Approach 1:
The invention maintains the simplicity of batch process manufacturing while achieving fine uniformity by changing only the shear rate parameter to 10^3 s^-1 or more. This single parameter modification transforms the batch process outcome from lumpy to fine and uniform without requiring complex continuous manufacturing equipment
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 method results in a finer urea grease that maintains excellent heat resistance and acoustic characteristics without visible lumps, enhancing its suitability for applications like ball bearings in small motors.
Implementation Method 1
shearing a mixture solution at a shear rate of 10^3 s^-1 or more
Data Source
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AI summary
A urea grease of the invention is prepared by applying shear at a shear rate of 102s-1 or more to a mixture solution of an amine mixture containing an alicyclic monoamine and a chain aliphatic monoamine, and a diisocyanate compound to cause a reaction in the mixture, in which the urea grease has Peak High32-64s of 1.5 or less and Level High32-64s of 10 or less according to an FAG method.