Wiper Blade Rubber Composition for Abrasion and Ozone Resistance
Solution Overview
Problem
Conventional windshield wiper blades made from natural and synthetic rubbers suffer from abrasion, fatigue, and rapid deterioration due to friction, oxidation, and ozone exposure, leading to a need for improved abrasion resistance and longevity.
Innovation Solution
A windshield wiper blade with a rubber structure comprising an elastomeric matrix of 25-60 phr natural rubber, 40-75 phr polybutadiene, 4-20 phr oil, and a mixture of 4-20 phr protective agents including antioxidants and antiozonants, along with a reinforcing particulate filler and vulcanization agents, which is molded and crosslinked to enhance durability and resistance to UV radiation and ozone.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional natural rubber or synthetic elastomers are used for wiper blades, then the blades can be manufactured with basic flexibility and wiping function, but the blades suffer from rapid abrasion, fatigue, and deterioration due to friction, oxidation, and ozone exposure
Solution Approach 1:
The patent uses a composite elastomeric matrix combining natural rubber (25-60 phr) with polybutadiene (40-75 phr). This composite material leverages the high elasticity and friction resistance of natural rubber while incorporating polybutadiene's superior abrasion resistance and fatigue resistance, creating a material that outperforms conventional single-elastomer compositions in durability and service life.
Solution Approach 2:
The patent optimizes the compositional parameters of the elastomeric matrix by controlling the ratio of natural rubber to polybutadiene within specific ranges (25-60 phr and 40-75 phr respectively). This parameter optimization ensures the balance between flexibility, abrasion resistance, and fatigue resistance, resolving the contradiction between basic functionality and enhanced durability.
2Reliability
If conventional rubber compositions are used, then the blades can perform basic wiping functions, but they deteriorate quickly due to oxidation and ozonolysis mechanisms
Solution Approach 1:
The patent introduces protective agents as intermediary substances that mediate between the elastomeric matrix and harmful environmental factors (oxygen, ozone, UV radiation). These protective agents act as antioxidants and antiozonants, forming a protective barrier that prevents direct attack on the rubber polymer chains, thereby significantly extending the service life and aging resistance of the wiper blade.
3Ease of operation
If the lower apex of the wiper blade is designed to contact the windshield, then effective water evacuation is achieved, but repeated friction causes abrasion and aging of the blade
Solution Approach 1:
The patent changes the material parameters of the elastomeric matrix by incorporating polybutadiene, which has superior friction resistance and abrasion resistance compared to conventional single-elastomer compositions. This material parameter change allows the blade to maintain effective contact with the windshield while significantly reducing friction-induced abrasion and aging.
Solution Approach 2:
The composite elastomeric matrix combining natural rubber and polybutadiene provides both the flexibility needed for effective windshield contact and the abrasion resistance to withstand repeated friction. The synergistic combination of these two elastomers resolves the contradiction between wiping effectiveness and friction resistance.
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 significantly improves abrasion resistance, fatigue resistance, and ozone and UV aging resistance, extending the lifespan of the wiper blades while maintaining good tearability and compression properties.
Implementation Method 1
The wiper blades are made of natural rubber (NR) or synthetic elastomers... These blades rub against the windshield and evacuate water... The windshield wiper blades and, in particular, the lower apex of the triangular shape of these blades in contact with the windshield, are subject to repeated friction. This friction causes abrasion of the blades
Implementation Method 2
windshield wiper blades made from both natural and synthetic rubbers are likely to deteriorate more or less quickly after prolonged exposure to the atmosphere due to known mechanisms of oxidation and ozonolysis
Implementation Method 3
windshield wiper blades made from both natural and synthetic rubbers are likely to deteriorate more or less quickly after prolonged exposure to the atmosphere due to known mechanisms of oxidation and ozonolysis
Implementation Method 4
The composition is crosslinked in the wiper blade mold... at least 0.5 phr of at least one vulcanization activator; and at least 0.6 phr of at least one vulcanization accelerator or ultra-accelerator
Data Source
Figure 1
AI summary
The invention relates to a wiper blade, in particular a wiper blade comprising a rubber structure, to a method for producing such a blade, and to a wiper frame device. According to the invention, the rubber structure is formed from an elastomer matrix comprising: between 25 and 60 phr of natural rubber; and between 40 phr and 75 phr of polybutadiene.