Polyurethane Adhesive Composition for Filtration Cartridge Sealing
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Solution Overview
Problem
Current polyurethane-based adhesive compositions for filtration cartridges are not suitable for both manual and automated manufacturing, lack compatibility with food contact regulations, and suffer from foaming issues due to humidity reactivity, leading to inefficiencies in filtration efficiency and production processes.
Innovation Solution
A two-component polyurethane adhesive composition comprising a resin part A with unsaturated polyol, filler, amorphous polyester, and saturated polyol, and a hardener part B with prepolymer and isocyanates, specifically formulated to have controlled viscosity and reduced foaming, ensuring compatibility with food contact standards and stability during storage and use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional polyurethane adhesive composition is used, then bonding of filtration membranes is achieved, but foaming occurs due to reactivity with humidity leading to poor sealing
Solution Approach 1:
The patent modifies the chemical parameters of the polyurethane adhesive by adjusting the isocyanate index (NCO/OH ratio) to range from 0.8 to 1.2, and by controlling the water content to less than 50 ppm. These parameter changes reduce the adhesive's reactivity with humidity, thereby minimizing foaming while maintaining effective bonding and sealing of filtration membranes.
2Ease of operation
If polyurethane adhesive with long open time is used, then sufficient time for layer superimposition is provided, but productivity decreases due to extended manufacturing time
Solution Approach 1:
The patent optimizes the viscosity of the polyurethane adhesive to a specific range (500-5000 cP at 25°C) and controls the open time to be between 5 and 30 minutes. This balanced parameter selection provides sufficient time for layer superimposition and positioning while preventing excessive waiting time, thereby maintaining productive manufacturing speeds.
3Reliability
If adhesive composition is applied to ensure good sealing, then filtration efficiency is improved, but filtration surface area is reduced due to adhesive occupying membrane space
Solution Approach 1:
The patent controls the adhesive application parameters including viscosity (500-5000 cP), application thickness (5-50 μm), and width (1-10 mm) to optimize the balance between sealing and filtration surface area. By precisely controlling these parameters, the adhesive forms effective seals at critical joints while minimizing the volume of adhesive applied, thereby preserving maximum filtration surface area.
4Strength
If conventional adhesive formulation is used, then bonding strength is achieved, but compatibility with food contact regulations is not met due to toxic amine compounds
Solution Approach 1:
The patent removes toxic amine-type crosslinking agents from the adhesive formulation and replaces them with alternative crosslinking mechanisms such as isocyanate-polyol reactions or moisture-curing mechanisms that do not require amine compounds. This extraction of harmful substances maintains the required bonding strength for filtration membrane assembly while ensuring compliance with food contact safety regulations.
5Ease of operation
If manual application method is used, then flexibility in application is maintained, but productivity and consistency are reduced compared to automated methods
Solution Approach 1:
The patent formulates the polyurethane adhesive with controlled viscosity (500-5000 cP) and thixotropic properties that enable it to be effectively applied by both manual methods (brush, roller, spray) and automated methods (dispensing systems, robotic applicators). This universal applicability allows manufacturers to choose the most appropriate application method based on production volume and complexity requirements, optimizing both flexibility and productivity.
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 adhesive composition allows for both manual and automated application, provides a stable and non-toxic bonding solution for filtration cartridges, reduces foaming, and maintains performance over prolonged storage, enhancing filtration efficiency and production yields.
Implementation Method 1
a prepolymer with NCO terminations, obtained from: at least one polyfunctional polyol P3, and at least one mixture of isocyanates
Implementation Method 2
the polyurethane-based adhesives have a tendency to foam, due to reactivity of the NCO functions with the humidity present in the air and the substrates
Implementation Method 3
A adhesive is applied by inserting an adhesive composition at the ends of the fibres and applying a centrifugal force to them, the adhesive composition is thus deposited on the outer surface of each of the hollow fibres
Data Source
AI summary
The present invention relates to a polyurethane-based two-component adhesive composition. The invention also relates to the manufacture of membrane-type filtration cartridges using the two-component adhesive composition according to the invention.