Bi-component drip emitter with elastomer labyrinth flow restriction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Bi-component drip emitters face challenges in achieving reliable flow rate compensation due to sensitivity to geometry variations and positioning issues when attached to irrigation hose walls, particularly with thermoset elastomers like silicone failing to bond firmly with rigid polymer materials during bi-component molding.
Innovation Solution
A bi-component drip emitter design featuring an elastomer component with a labyrinth flow restriction, including a sequence of baffles and a base, where the elastomer component is integrally formed with under-tooth or over-tooth bypass spaces that close under fluid pressure, and a rigid polymer component extending around the elastomer to provide mechanical retention and improved bonding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a separate elastomer diaphragm is used for pressure compensation, then flow rate regulation is improved, but device complexity increases due to multiple parts and assembly steps
Solution Approach 1:
The patent integrates the elastomer pressure compensation element directly into the rigid polymer body of the drip emitter, eliminating the separate diaphragm component. The elastomer is molded as an integral part of the rigid structure, combining two previously separate components into one unified device, thus reducing assembly steps while maintaining pressure compensation functionality
2Productivity
If extrusion process is used to form elastomer component, then production efficiency is improved, but manufacturing precision deteriorates and shape flexibility is limited
Solution Approach 1:
The patent replaces the extrusion process with injection molding for producing the elastomer component. Injection molding provides superior manufacturing precision and greater shape flexibility compared to extrusion, while maintaining high production efficiency. This process substitution enables complex geometries with tight tolerances to be achieved at scale
3Stability of the object's composition
If thermoset elastomer like silicone is used, then resistance to creep is improved, but bonding capability with rigid polymer deteriorates
Solution Approach 1:
The patent utilizes the thermosetting properties of silicone elastomer, changing its physical state from liquid to solid through curing. This parameter change enables the elastomer to achieve high creep resistance in its cured state while the molding process ensures strong bonding to the rigid polymer component during the liquid phase, before final curing
4Manufacturing precision
If bi-component injection molding is used, then manufacturing precision is improved, but difficulty of manufacture increases due to process complexity
Solution Approach 1:
The patent combines the elastomer and rigid polymer components into a single integrated part through bi-component injection molding. This merging eliminates the need for separate molding and assembly operations, reducing process complexity despite the advanced molding technique used. The two materials are injected sequentially in the same mold cavity, ensuring precise positioning without additional alignment steps
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 design enhances flow rate regulation and reduces sensitivity to positioning variations, ensuring effective retention of the silicone elastomer component and improved manufacturing precision, leading to more reliable and efficient drip irrigation systems.
Implementation Method 1
the base is exposed to the fluid pressure within the irrigation hose such that increased fluid pressure within the irrigation hose causes progressive closing of the under-tooth bypass spaces, thereby regulating the flow rate through the drip emitter
Data Source
Figure 1A~4B
Figure 2
Figure 3A~3D
AI summary
A drip emitter formed from an elastomer component and a rigid polymer component for welding to the inner surface of an irrigation hose. The drip emitter has a fluid flow pathway including a flow restriction, typically in the form of a labyrinth, formed at least partially within the elastomer to provide a variable geometry flow restriction. The flow restriction may include under- tooth bypass spaces located between the base and the sequence of baffles, over- tooth bypass clearances or may employ baffles with a thickened root portion which forms a sloped transition region between an upright upper wall portion and the base. In each case, flow through the drip emitter when deployed is regulated by pressure-responsive deformation of the elastomer component. Some implementations employ a thermoset elastomer component such as silicone with mechanical interlocking between the components.