Thermoplastic Polyurethane Membrane for Irrigation Emitters
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Thermoplastic polyurethane (TPU) formulations used in irrigation devices face limitations in achieving desired physical properties such as hardness, chemical resistance, and shelf life, which restrict their application in irrigation systems, particularly in membrane-based emitters where existing materials are costly and have limited durability.
Innovation Solution
A TPU formulation composed of a polyol with an OH value ranging from 50 mg KOH/g to 500 mg KOH/g, a chain extender, a triol, and an isocyanate with functionality between 1.5 and 3.0, which is processed to achieve a Shore A hardness of 30 to 100, enhancing structural resilience and chemical resistance while allowing for a simpler manufacturing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional TPU formulations are used in irrigation devices, then basic flexibility and processability are maintained, but desired physical properties such as hardness, chemical resistance, and shelf life are not achieved
Solution Approach 1:
The patent applies parameter changes by precisely controlling the OH value of polyols (50-500 mg KOH/g) and isocyanate functionality (1.5-3.0) to optimize TPU formulation. This systematic parameter adjustment enables achievement of desired chemical resistance, hardness, and shelf life while maintaining processability, thereby resolving the contradiction between reliability and adaptability
Solution Approach 2:
The patent employs composite material principles by formulating TPU with specific combinations of polyols, chain extenders, triols, and isocyanates. This composite approach creates a material system that simultaneously achieves enhanced chemical resistance, structural resilience, and versatility for various irrigation applications including membrane-based emitters
2Reliability
If silicone rubber film is used for membrane/diaphragm in PC drip emitters, then desired elasticity and pressure compensating function are achieved, but cost increases and shelf life is limited
Solution Approach 1:
The patent applies the principle of replacing expensive, short-lived materials with more durable, cost-effective alternatives. By developing TPU formulations with extended shelf life and maintained elasticity, the invention replaces silicone rubber films in membrane-based emitters, achieving both economic and performance benefits while resolving the contradiction between reliability and duration
3Strength
If TPU formulations are refined with crosslinks using isocyanates, then physical properties such as toughness and flexibility are improved, but other properties such as hardness and chemical resistance deteriorate
Solution Approach 1:
The patent resolves this contradiction through precise parameter control, specifically optimizing the OH value range of polyols (50-500 mg KOH/g) and isocyanate functionality (1.5-3.0). This controlled parameter adjustment enables the formulation to achieve desired toughness through crosslinking while maintaining adequate hardness and chemical resistance, preventing the deterioration of critical properties
4Reliability
If a membrane-based emitter is used in irrigation devices, then pressure compensating function is achieved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent applies composite material principles by formulating TPU with specific combinations of polyols, chain extenders, triols, and isocyanates to create a material that can be processed into membrane-based emitters using conventional techniques. This composite approach maintains pressure compensating function while enabling simpler manufacturing, thereby resolving the contradiction between reliability and device complexity
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 TPU formulation provides improved structural resilience, long shelf life, and strong chemical resistance, enabling its use in irrigation devices with membrane-based emitters, specifically pressure compensating drip emitters, while simplifying the manufacturing process and reducing costs.
Implementation Method 1
A TPU formulation composed of a polyol with an OH value ranging from 50 mg KOH/g to 500 mg KOH/g, a chain extender, a triol, and an isocyanate with functionality between 1.5 and 3.0
Data Source
AI summary
A thermoplastic polyurethane (TPU) formed as a reaction product of a polyol composition, at least one chain extender, at least one triol and an isocyanate composition. An irrigation device comprising an emitter defined by a body, a cover and at least a membrane and an irrigation hose, wherein the membrane is made of the TPU. Use of TPU for production of injection molded products, extrusion products, films, perforated films, membranes, and shaped bodies.