Grease Composition with Thixotropic Polyamide for High-Temperature Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current lithium soap based greases are limited by their resistance to high-temperatures, wet environments, and shear, leading to reduced working life and increased maintenance in industrial applications such as steel mills and paper mills, where high moisture, heat, and shear conditions are prevalent.
Innovation Solution
A grease composition comprising a base oil, a water insoluble thickener, and a low molecular weight thixotropic polyamide with specific molecular weight distribution characteristics, along with performance additives, to enhance water resistance and mechanical stability at elevated temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If lithium soap based grease is used, then acceptable lubricating performance is provided, but resistance to high-temperatures, wet environments, and shear is limited
Solution Approach 1:
The grease composition combines lithium soap thickener with polyalphaolefin base oil and polymer additives to create a composite material that achieves both high-temperature resistance and extended working life. The composite structure allows the grease to maintain stability at temperatures up to 140°C while extending working life through synergistic interactions between components.
Solution Approach 2:
The invention changes the chemical composition parameters by incorporating specific polymer additives and optimizing the base oil composition. This allows the grease to transition from limited high-temperature resistance to enhanced stability and extended working life under harsh conditions.
2Reliability
If polymers are used to increase structural stability and water resistance, then desirable grease characteristics are obtained, but low temperature mobility is severely limited
Solution Approach 1:
The grease formulation uses different components with specialized functions: lithium soap provides structural stability and water resistance, while polyalphaolefin base oil maintains low-temperature mobility. The polymer additives are incorporated at optimized levels to enhance specific properties without compromising overall performance across temperature ranges.
Solution Approach 2:
The invention optimizes the molecular weight and composition of polymer additives to achieve the right balance between structural stability and low-temperature mobility. By carefully controlling polymer parameters and base oil selection, the grease maintains pumpability at low temperatures while providing enhanced water resistance and structural stability.
3Reliability
If high viscosity base stocks are used to improve water resistance, then structural stability is increased, but low temperature mobility is severely limited
Solution Approach 1:
The grease uses a composite base oil system combining polyalphaolefin with specific viscosity characteristics and polymer additives. This composite approach provides water resistance through the polymer components while the polyalphaolefin base maintains low-temperature mobility, avoiding the need for high viscosity base stocks alone.
Data Source
AI summary
The present disclosure provides a grease composition with improved water resistance and mechanical stability at high-temperatures, including: at least one base oil; a water insoluble thickener; and a low molecular weight thixotropic polyamide composition having molecular weight distribution characteristics meeting the requirement described by the relationship:(A+D)(B+C)≥0.05where A=the % mass of the polyamide composition with a molecular weight greater than 1700 AMU; B=the % mass of the polyamide composition with a molecular weight between 1100 AMU and 1300 AMU; C=the % mass of the polyamide composition with a molecular weight between 700 AMU and 1000 AMU; and D=the % mass of the polyamide composition with a molecular weight of 600 AMU or lower (determined by GPC). The grease composition of the present disclosure provides a less than 50 penetration point change as determined by ASTM-D7342, a less than 10 mg weight loss as determined by ASTM-D4170, or both.