Polyamide Moulding Composition for Flexible Automotive Air Tubes
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Solution Overview
Problem
Existing polyamide moulding compositions for blow moulding lack flexibility, calcium chloride resistance, and thermal ageing resistance, and often suffer from delamination under dynamic-mechanical stress, making them unsuitable for producing flexible tubes and hoses with high mechanical and thermal performance.
Innovation Solution
A thermoplastic moulding composition comprising 51-69.9 wt % polyamide elastomer, 15-38 wt % ethylene-α-olefin copolymer grafted with maleic anhydride, 3-25 wt % polyamide, and 0.1-2 wt % heat stabilizers, specifically optimized to achieve a melt strength of 30-70 seconds, tensile elasticity modulus of 200-600 MPa, and resistance to delamination after 1.3 million cycles at 150°C.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If polyamide moulding compositions with high melt strength are used for blow moulding, then the structural integrity during extrusion is improved, but the surface quality deteriorates and flexibility is reduced
Solution Approach 1:
The patent applies parameter changes by precisely controlling the melt strength within a specific range (30-70 seconds) through formulation adjustments. This resolves the contradiction by finding the optimal parameter window that satisfies both structural integrity requirements during extrusion and surface quality requirements for the final product.
Solution Approach 2:
The patent uses composite materials by formulating a blend containing 51-69.9 wt% polyamide elastomer, 15-38 wt% ethylene-α-olefin copolymer grafted with maleic anhydride, and 3-25 wt% polyamide. This composite approach allows balancing melt strength and surface quality by combining materials with complementary properties.
2Strength
If polyamide moulding compositions with high stiffness are used, then structural strength is improved, but flexibility deteriorates
Solution Approach 1:
The patent employs composite materials with a specific formulation ratio where polyamide elastomer (51-69.9 wt%) provides flexibility while polyamide (3-25 wt%) contributes structural strength. The ethylene-α-olefin copolymer grafted with maleic anhydride acts as a compatibilizer to ensure proper interfacial adhesion between these components, achieving both structural strength and flexibility simultaneously.
Solution Approach 2:
The patent changes the material parameters by controlling the elasticity modulus within the range of 200-600 MPa through formulation optimization. This parameter control allows the material to achieve both sufficient structural strength and required flexibility for automotive air suspension applications.
3Ease of operation
If polyamide elastomer content is increased to improve flexibility, then flexibility is improved, but resistance to delamination under dynamic-mechanical stress deteriorates
Solution Approach 1:
The patent introduces an intermediary substance - ethylene-α-olefin copolymer grafted with maleic anhydride (15-38 wt%) - that acts as a compatibilizer between the polyamide elastomer and polyamide phases. This intermediary ensures strong interfacial adhesion and prevents delamination under dynamic-mechanical stress while allowing high polyamide elastomer content for flexibility.
Solution Approach 2:
The patent uses a three-component composite material system where each component has a specific function: polyamide elastomer provides flexibility, polyamide provides structural integrity, and the grafted copolymer ensures interfacial adhesion. This balanced composite formulation resolves the contradiction between flexibility and delamination resistance.
4Ease of manufacture
If existing polyamide compositions are used for blow moulding, then production is simplified, but calcium chloride resistance and thermal ageing resistance deteriorate
Solution Approach 1:
The patent uses a specific composite material formulation with polyamide elastomer, polyamide, and ethylene-α-olefin copolymer grafted with maleic anhydride in controlled ratios. This composite approach provides both calcium chloride resistance and thermal ageing resistance while maintaining extrusion blow mouldability, achieving enhanced performance without excessive production complexity.
Data Source
AI summary
Thermoplastic moulding composition consisting of(A) 51 to 69.9 wt % of polyamide elastomer;(B) 15 to 38 wt % of ethylene-α-olefin copolymer;(C) 3 to 25 wt % of polyamide selected from the group consisting of: PA6, PA66, PA6/66, PA610, PA612, PA614, PA616, PA6/610, PA66/610 or mixtures thereof;(D) 0.1 to 2.0 wt % of heat stabilizers based on copper and/or iodide, organic stabilizers or a mixture thereof;(E) 0 to 5.0 wt % of additives, different from (A) to (D);where the sum of (A) to (E) makes 100 wt % of the total moulding composition, and with the proviso that the sum of (B) and (C) is in the range from 30 to 48 wt % based on the total moulding composition.