Silicone Rubber Valve Slit Design for Bonding Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Valves with slit openings made of liquid silicone rubber tend to fail due to molecular bonding across the slit, preventing the valve from opening when pressure differences occur, requiring manual intervention that is unhygienic and complex, leading to high failure rates in applications like baby bottles and spout cups.
Innovation Solution
A valve design with an inner space having a smaller first end and a larger second end, where the first end's dimension is between 0 mm and 0.2 mm, and a closing part thickness of up to 0.1 mm, ensuring the valve can open without manual intervention by easily breaking under pressure, and a manufacturing method using a mold structure to produce such valves without additional cutting steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a slit valve is made of liquid silicone rubber and produced by liquid injection molding followed by a slitting process, then the valve can control beverage flow, but the macromolecules and atoms in the walls on each side of the slit tend to bond again together, causing the slit to close and the valve function to fail
Solution Approach 1:
The patent applies preliminary action by pre-forming the slit opening during the liquid injection molding process itself, rather than creating it afterward through slitting. The mold cavity is designed with a specific geometry that maintains an open slit configuration during curing. This preliminary structuring prevents the molecular bonding issue from occurring in the first place, as the slit walls are formed with appropriate spacing and structural support already in place.
Solution Approach 2:
The patent changes the geometric parameters of the slit structure, specifically setting the first end dimension between 0-0.2mm and the closing part thickness to 0.1mm or less. These parameter changes ensure the slit remains functional - small enough to prevent excessive bonding but large enough to allow opening under pressure. The thickness parameter of the closing part is critically controlled to prevent complete sealing while maintaining structural integrity.
2Ease of operation
If the slit closes due to molecular bonding, then the valve cannot open automatically when pressure difference occurs, but manual intervention is required to crack the slit open, which is unhygienic and complex
Solution Approach 1:
The patent implements self-service by designing the valve to automatically open itself when pressure difference occurs, without requiring manual intervention. The controlled geometry of the slit and closing part allows the valve membrane to rupture or open automatically under suction pressure, enabling the child to use the drinking appliance without adult assistance. This eliminates the need for foreign objects like hands or pins to crack the slit open.
Solution Approach 2:
The patent prepares the slit structure in advance during manufacturing with specific dimensional parameters that enable automatic opening. The first end dimension of 0-0.2mm and closing part thickness of 0.1mm or less are pre-configured to ensure the slit can be easily opened by pressure differential alone, eliminating the need for subsequent manual cracking operations.
3Reliability
If additional slitting or cutting steps are applied after manufacturing to ensure the slit opens, then the manufacturing process becomes more complex and additional equipment is required, but the slit valve can be ensured to open
Solution Approach 1:
The patent merges the slit formation process with the main liquid injection molding process. By integrating the slit creation into the primary manufacturing step through clever mold cavity design, the patent eliminates the need for separate slitting or cutting operations. The mold cavity geometry itself creates the functional slit structure during curing, combining multiple functions into a single manufacturing step and simplifying the overall production process.
Solution Approach 2:
The patent performs the slit formation action preliminarily during the injection molding process itself. The mold cavity is designed to maintain the slit in an open configuration during manufacturing, so the functional geometry is established before the valve is even removed from the mold. This preliminary structuring eliminates the need for subsequent processing steps to ensure the slit will open.
4Ease of operation
If the first end dimension is made very small to prevent molecular bonding, then the valve can open more easily, but the opening may be too small to allow adequate flow when open
Solution Approach 1:
The patent applies asymmetry by creating a tapered slit geometry where the first end is narrow (0-0.2mm) and the second end is wider. This asymmetric configuration allows the narrow end to prevent molecular bonding and enable easy opening, while the wider second end provides adequate flow passage when the valve is open. The asymmetric shape optimizes both opening ease and flow capacity simultaneously.
Solution Approach 2:
The patent resolves the contradiction by transitioning from a one-dimensional concern (slit width) to a two-dimensional geometry (tapered slit with varying width). By allowing the slit dimension to change along its length - narrow at the first end, wider at the second end - the patent simultaneously achieves easy opening at the critical first end while maintaining adequate flow capacity through the wider second end portion.
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 valve design reduces the likelihood of failure by ensuring the valve can function reliably without manual opening, maintaining hygiene and simplifying the manufacturing process, while preventing liquid leakage and sticking issues.
Implementation Method 1
Valves made of rubber, in particular, made of liquid silicone rubber (LSR), with slit openings are used in beverage feeding appliances, in order to control the flow of the beverage
Data Source
AI summary
A valve, such as for feeding appliances, has an inner space and walls partly enclosing the inner space. The inner space has a smaller first end and an opposing larger second end. The first end has a dimension being larger than 0 mm and smaller than or equal to 0.2 mm, and the inner space forms an opening through the valve or is closed at the first end by a closing part of the valve. The closing part of the valve has a thickness which is smaller than or equal to 0.1 mm.