Dispensing Pump with Polymer Spring for All-Plastic Recyclability
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Solution Overview
Problem
Existing dispensing pumps for liquids and viscous materials face challenges in recycling due to the presence of metal springs, which require separation from plastic components, hindering the recycling process.
Innovation Solution
A dispensing pump with a polymer compression spring assembly, featuring a slotted tubular spring element and loading cones made from tensile polymer materials, allowing for radial expansion and contraction, enabling easy recyclability as all components can be molded from the same plastic material.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a metal spring is used in the dispensing pump, then the spring provides reliable compression and extension force, but the metal spring impedes recycling due to the need to separate it from plastic components
Solution Approach 1:
The patent applies homogeneity by replacing the metal spring with a polymer compression spring made from the same plastic material as other pump components. This creates a homogeneous material composition throughout the pump assembly, eliminating the need for material separation during recycling and directly resolving the contradiction between maintaining reliable spring function and improving recyclability.
Solution Approach 2:
The patent changes the material parameter of the spring from metal to polymer, while maintaining the compression spring's functional parameters (elasticity, compression ratio, force output). This parameter change allows the spring to be made from recyclable plastic material while preserving its mechanical function, thus resolving the contradiction between reliability and ease of recycling.
2Ease of manufacture
If a polymer compression spring is used instead of metal spring, then recycling becomes easier as all components can be molded from the same plastic material, but the spring must withstand repeated compression and extension cycles
Solution Approach 1:
The patent changes the material parameter from metal to polymer while selecting polymer materials with appropriate mechanical properties (elasticity, fatigue resistance, tensile strength) to ensure the spring can withstand repeated compression and extension cycles. This parameter change enables both improved recyclability and maintained durability through careful material selection.
Solution Approach 2:
The patent employs composite material strategies by using reinforced polymer formulations or blended plastics that combine recyclability with enhanced mechanical properties. The compression spring is made from composite polymer materials that provide both the desired elastic behavior for repeated cycling and compatibility with recycling processes, resolving the contradiction between ease of recycling and duration of action.
3Ease of manufacture
If the spring is made from tensile polymer material, then the spring can be molded from the same plastic material as other components, but the polymer material must maintain elasticity over time
Solution Approach 1:
The patent changes the material parameter to tensile polymer materials that can be molded while maintaining elastic properties. By selecting specific polymer types and formulations with appropriate viscoelastic characteristics, the spring achieves both ease of molding from plastic material and long-term elasticity stability, resolving the contradiction between manufacturing ease and compositional stability.
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 all-plastic dispensing pump assembly facilitates efficient recycling and maintains the functionality of traditional metal spring-based systems, ensuring effective dispensing and extended spring life through strain distribution and optimized design.
Implementation Method 1
The tubular spring element is disposed coaxially about the piston stem between the first and second loading cones. When the dispensing head is compressed, the loading cones are axially compressible toward each other within the slotted tubular spring element whereby the slotted tubular spring element radially expands in tension to create an opposing radial contraction force, and in turn, an axial extension spring force.
Implementation Method 2
When released, the spring element elastically returns to its normal at rest shape, returning the loading cones and dispensing head to their normal at rest positions.
Data Source
AI summary
A dispensing pump includes a polymer compression spring assembly, base vents and a flow baffle. The dispensing pump includes a pump base, and a dispensing head having a piston stem. The polymer compression spring assembly includes a slotted tubular spring element and first and second loading cones received at opposing ends of the slotted tubular spring element. The venting ports allow air to escape when capping the container after filling and the flow baffle reduces or prevents the product from being pulled into the pump accumulator before residual air (headspace) has been evacuated from the container during the initial priming strokes.