Polymer Lamination Using Solvent-Assisted Ultrasonic Bonding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for laminating polymeric components suffer from deformation, poor bonding strength, long cycle times, and low accuracy, particularly in high-throughput manufacturing, due to issues like intermediate layer use, thermal bonding inefficiencies, and polymer mixing at elevated temperatures.
Innovation Solution
A method involving the application of a solvent to the connecting surfaces of polymeric components, followed by securing before evaporation, and applying ultrasonic energy to form a viscoelastic interface layer, which reduces the glass transition temperature and enables efficient bonding with precise solvent application.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional welding methods based on heat generation through friction are used, then bonding strength is improved, but polymer deformation and flow to undesired locations occur
Solution Approach 1:
The patent changes the temperature parameter by using localized heating through ultrasonic vibration at the bonding interface rather than bulk heating, maintaining temperature below the polymer's melting point to prevent deformation while achieving sufficient bonding strength through controlled interdiffusion at the interface
Solution Approach 2:
The patent applies ultrasonic vibration mechanically to the bonding interface to generate localized heat through friction and viscoelastic heating, enabling polymer chain interdiffusion and bonding without bulk heating, thus preventing deformation while achieving strong bonds
2Strength
If intermediate layers such as glue or tape are used to connect polymers, then bonding is achieved, but accuracy and functional properties are degraded
Solution Approach 1:
The patent extracts and eliminates the intermediate layer (adhesive or tape) from the bonding process, achieving direct polymer-to-polymer bonding through ultrasonic-assisted interdiffusion at the interface, thereby removing the source of accuracy degradation and functional property compromise
Solution Approach 2:
The patent uses the polymer interface itself as the mediator for bonding, where ultrasonic energy facilitates direct chain interdiffusion between the two polymer components without requiring any intermediate material, thus maintaining both accuracy and functional properties
3Temperature
If thermal bonding using plasma treatments is used, then bonding is achieved at temperature below glass-transition temperature, but cycle time becomes extremely long
Solution Approach 1:
The patent uses ultrasonic vibration to generate localized heat at the bonding interface through mechanical energy conversion, enabling rapid bonding within seconds by concentrating energy at the interface rather than heating the entire component, thus dramatically reducing cycle time while maintaining temperature control
Solution Approach 2:
The patent employs periodic ultrasonic pulses or continuous ultrasonic vibration at controlled duty cycles to achieve bonding in rapid succession, enabling high-throughput manufacturing by repeating the bonding cycle quickly without requiring long heating periods
4Productivity
If conventional welding methods are used for large scale manufacturing, then throughput is increased, but elongation times and cycle times prevent high throughput
Solution Approach 1:
The patent uses ultrasonic vibration to enable rapid bonding cycles of a few seconds by localizing energy input at the bonding interface, allowing continuous high-speed processing and eliminating the need for slow diffusion-based bonding, thus achieving high throughput manufacturing
Solution Approach 2:
The patent prepares the polymer surfaces in advance by ensuring proper alignment and contact before applying ultrasonic energy, enabling immediate bonding upon energy application and eliminating setup delays, thus maximizing throughput in large-scale manufacturing
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
This method achieves high-accuracy, high-throughput bonding with reduced cycle times, improved bonding strength, and minimal deformation, while using less energy and safer, environmentally friendly solvents, suitable for manufacturing microfluidic devices.
Implementation Method 1
the solvent migrates into the polymer of the at least one connecting surface, causing a swollen and more viscous interface layer
Implementation Method 2
the interface layer may be a mixture of the polymer of one of the at least two polymeric components and the solvent. It was found that said interface layer (also referred to as intermediate layer) is softer compared to the polymeric component, due to swelling of the interface layer by the solvent
Implementation Method 3
applying ultrasonic energy
Implementation Method 4
the at least one connecting surface is already viscoelastic and thus the viscoelastic heating regime as applies on the contacting surfaces of the at least two polymeric components
Implementation Method 5
the solvent provided to at least parts of the at least one connecting surface causes a reduction of the glass transition temperature of the polymer of the at least one connecting surface
Implementation Method 6
the interface layer (which is swollen) ensures a good contact surface by allowing compression of micro-scale topology differences
Data Source
AI summary
Method of laminating two polymeric components, preferably to form a microfluidic device, comprising the steps of: —providing two polymeric components (60, 62), each having a connecting surface (53); —providing a solvent (66) to at least one connecting surface (61, 53); —securing the connecting surface (61) of a first polymeric component (60) to the connecting surface (53) of a second polymeric component (62); —applying ultrasonic energy (68); and —thereby bonding the connecting surfaces of the first and second polymeric components (60, 62), wherein the step of securing is performed before the solvent (66) is substantially evaporated, and wherein the solvent (66) has a Ra-distance with respect to the polymeric component (60, 62) in the range of 4 MPa1/2 to 10 MPa1/2. Ideally, the solvent is a bio-based non-toxic solvent with a boiling point above 100° C., e.g. Isopropyl myristate or diethyl butanedionate.