Flame retardant vapor retarding membranes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current building materials struggle to balance flame retardancy with variable water vapor permeability, especially at different relative humidity levels, and are often costly to produce, with existing solutions failing to meet both criteria simultaneously.
Innovation Solution
A flame retardant vapor retarding membrane comprising a building material substrate sheet and a polymeric coating layer, both with melt viscosities of about 1 Pa·s to 100,000 Pa·s, which provides low water vapor permeance at low humidity and high permeance at high humidity, achieved through a cost-efficient coating process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If interior moisture barriers provide low permeability across all conditions, then flame retardancy is improved, but water vapor permeability during high relative humidity deteriorates
Solution Approach 1:
The vapor retarding membrane transitions from a static low-permeability structure to a dynamic system that adjusts its water vapor permeability based on relative humidity conditions. The membrane maintains flame retardancy while adapting its permeability characteristics to match varying environmental conditions, allowing high permeability during high humidity and low permeability during low humidity.
Solution Approach 2:
The membrane's water vapor permeability parameter is changed dynamically in response to relative humidity conditions. The material exhibits different permeability states depending on the humidity environment, transforming from a fixed-permeability barrier to a variable-permeability system that optimizes both flame safety and moisture management.
2Adaptability or versatility
If smart vapor retardant products provide variable vapor permeability, then water vapor permeability during high relative humidity is improved, but flame retardancy deteriorates
Solution Approach 1:
The invention combines multiple material characteristics into a composite vapor retarding membrane that simultaneously achieves variable water vapor permeability and flame retardancy. The composite structure integrates the adaptive permeability features with flame-resistant properties, resolving the contradiction between smart vapor regulation and fire safety.
3Adaptability or versatility
If extruded thermoplastic films are used for smart vapor retardant, then variable vapor permeability is improved, but manufacturing cost deteriorates
Solution Approach 1:
The invention employs cost-effective materials and manufacturing approaches to create flame retardant vapor retarding membranes. By using affordable substrates and coating materials that can be processed through economical methods, the solution reduces manufacturing costs while maintaining the required performance characteristics of variable permeability and flame safety.
4Ease of manufacture
If coating is used as fabrication methodology, then manufacturing cost is improved, but flame retardancy deteriorates
Solution Approach 1:
The coating process parameters and material composition are optimized to achieve flame retardancy in coated membrane materials. By adjusting the coating formulation and application parameters, the invention successfully imparts flame-resistant properties to cost-effective coated substrates, overcoming the historical difficulty of passing flame tests with coated materials.
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 membrane effectively self-extinguishes within 5 seconds after flame removal and maintains desired permeability across a range of humidities, meeting stringent fire resistance and moisture management standards while being cost-effective.
Implementation Method 1
both having a melt viscosity of about 1 Pascal-second (Pa·s) to about 100,000 Pa·s, as measured at 300° C. and 1 rad/s
Implementation Method 2
provide both the desired flame retardant properties and desired water vapor permeability, particularly at variable relative humidity
Data Source
AI summary
The present disclosure relates generally to flame retarding building materials and methods for making them. More particularly, the present disclosure relates to flame retarding building materials that have both flame retardant character and desirable water vapor permeability values. In one embodiment, the disclosure provides a flame retardant vapor retarding membranes comprising: a building material substrate sheet having a melt viscosity of about 1 Pa·s to about 100,000 Pa·s at about 300° C. at 1 rad/s; and a polymeric coating layer disposed on the building material substrate layer, wherein the coating layer has a melt viscosity of about 1 Pa·s to about 100,000 Pa·s at about 300° C. at 1 rad/s.