Self-Sealing Roofing Laminate with Discontinuous Bitumen Coating
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Solution Overview
Problem
Conventional laminate construction materials for roofing, such as bituminous asphalt-based felts and synthetic laminates, face challenges including high weight, difficulty in application on sloped roofs, and inadequate resistance to liquid transport around fastening points like nails or staples, which can lead to water ingress and other issues.
Innovation Solution
A laminate construction material comprising a nonwoven layer with a superabsorbent material sandwiched between two coatings, where the superabsorbent material is randomly or non-randomly distributed to prevent or reduce liquid transport through the laminate, especially around punctures caused by fastening means, providing a self-sealing and lightweight solution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If thick bitumen layers are used in conventional felt laminates to provide nail sealable functionality, then water resistance around fastening points is improved, but weight per unit surface area increases significantly
Solution Approach 1:
The patent changes the physical state and distribution of the bitumen layer from thick and continuous to thin and discontinuous. The bitumen is applied as a thin coating (0.1-2.0 mils) with discontinuous coverage (20-80% surface area), fundamentally altering the parameters of layer thickness and coverage uniformity to reduce weight while maintaining sealing functionality.
Solution Approach 2:
The patent employs self-sealing mechanisms where the bitumen coating softens and flows under heat and pressure from installed fasteners, automatically sealing around nails or staples without requiring additional materials or manual intervention. This self-service approach eliminates the need for thick bitumen layers while maintaining water resistance.
2Reliability
If thick bitumen layers are used to provide nail sealable functionality, then sealing around fasteners is improved, but ease of application on sloped roofs deteriorates
Solution Approach 1:
The bitumen coating is formulated with specific rheological properties and thickness parameters (0.1-2.0 mils) that enable it to remain pliable and self-sealing at typical roofing temperatures, while the thin, discontinuous application makes the overall laminate more flexible and easier to handle and install on sloped surfaces.
3Weight of moving object
If discontinuous bitumen coating is used to reduce weight, then weight per unit surface area is reduced, but resistance to liquid transport around punctures may be compromised
Solution Approach 1:
The discontinuous bitumen coating performs self-sealing by softening and flowing around fastener shafts when heat and pressure are applied during installation, automatically creating a seal without requiring the coating to be continuous across the entire surface.
Solution Approach 2:
The bitumen coating provides localized sealing quality at fastening points rather than uniform coverage across the entire surface. The coating is strategically positioned to provide sealing functionality where needed (around punctures) while leaving other areas with reduced material, achieving local optimization of the water barrier property.
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 laminate construction material effectively prevents liquid transport and provides improved resistance to water, UV light, algae, fungi, mold, and rot, while being lightweight and easy to install, offering enhanced environmental protection and insulation.
Implementation Method 1
a super absorbent material present between the structure-facing major surface and the opposing major surface; wherein the amount of super absorbent material is present in an amount that prevents or reduces liquid transport in proximity to fastening means
Data Source
AI summary
A construction material that is a laminate including a nonwoven comprising a super absorbent material and a method of self-sealing liquid transport through the construction material in proximity to punctures in the laminate.