High Modulus Nylon 6,6 Yarns Fatigue Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing high modulus nylon 6.6 yarns used in pneumatic tires and mechanical rubber goods suffer from excessive stiffness and low bending fatigue resistance due to high temperature stretching, leading to a loss of properties after relaxation.
Innovation Solution
High modulus nylon 6.6 yarns are stretched between 5% and 12% at 230-250°C and wound with tension between 150g and 500g, maintaining rigidity and resistance through controlled relaxation prevention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If high stretch is applied at high temperature to increase modulus, then tensile modulus is improved, but bending fatigue resistance deteriorates
Solution Approach 1:
The patent applies parameter changes by precisely controlling the stretching temperature range (230-250°C) and stretch percentage (5-12%) to achieve the desired modulus improvement while minimizing the negative impact on bending fatigue resistance. This optimized parameter combination resolves the contradiction between tensile modulus and fatigue resistance.
2Stability of the object's composition
If high temperature stretching is applied to obtain stable properties, then thermal stability is improved, but yarn rigidity increases excessively
Solution Approach 1:
The patent resolves this contradiction by changing the temperature parameter to a specific range (230-250°C) that provides sufficient thermal stability while avoiding excessive rigidity. The controlled stretch percentage (5-12%) further modulates the rigidity level to maintain workability.
Solution Approach 2:
The patent introduces dynamic control through winding tension (150-500g) applied during the wounding process. This dynamic parameter adjustment allows the yarn to achieve stable properties while maintaining appropriate rigidity for subsequent processing and application.
3Ease of manufacture
If regular modulus yarns are used for single twisted yarn production, then ease of manufacture is improved, but the resulting yarn stiffness increases and fatigue resistance decreases
Solution Approach 1:
The patent resolves this contradiction by changing the fundamental parameters of the raw yarn (using high modulus nylon 6,6 with specific tensile stress >1.30cN/dtex at 4% elongation) and processing parameters (stretch 5-12% at 230-250°C). This ensures both ease of manufacture and improved fatigue resistance in the final product.
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 resulting high modulus yarns exhibit improved tensile stress, fatigue resistance, and thermal stability, maintaining properties in bobbins and rolls without significant modulus drop, suitable for tire reinforcement.
Implementation Method 1
the existing regular nylon 6.6 yarns having regular modulus (tensile stress level less than 1.25cN/dtex at 4% elongation, or tensile modulus level at 4% elongation less than 31.25cN/dtex or 35.4g/d) have been used. In order to obtain the high modulus single twisted yarns, high stretches at high temperatures have been applied
Implementation Method 2
wound up on bobbins or spools with a winding tension between 150g and 500g per yarn(strand). The high stretched yarns having high modulus maintain their properties in bobbins, because they are not permitted to relax
Data Source
AI summary
The high modulus single twisted nylon 6.6 yarns having tensile stress values at 4% elongation between 2.0 and 2.8cN/dtex are used as reinforcement in shaped rubber composites. The minimum heat shrinkage of the said cords is 4% and maximum heat shrinkage is 7%.