Polyester Nonwoven Roofing Ply With Latent Shrinkage Stability
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Solution Overview
Problem
Existing cores for bituminised roofing and sealing membranes suffer from dimensional instability, leading to shrinkage and deformation during processing and use, resulting in unevenness, leaks, and premature aging due to the lack of effective reinforcement methods, which complicate and increase the cost of production.
Innovation Solution
A reinforcement-free, bonded non-woven core made of polyester filaments with a controlled latent shrinkage force, produced through the spun-bond process, mechanical needle-punching, and thermal bonding, which counteracts strains during heat treatment by building a specific shrinkage force that cancels out subsequent thermal strains.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If glass scrims or longitudinal filaments are embedded to reinforce the core, then dimensional stability is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The invention extracts and eliminates the reinforcement components (glass scrims, filaments, meshes) from the core structure, achieving dimensional stability through the intrinsic properties of the bonded non-woven fabric itself rather than through added reinforcement layers
Solution Approach 2:
The invention changes the parameters of the bonded non-woven fabric, specifically ensuring it has a latent shrinkage force that counteracts strains during heat treatment, thereby achieving dimensional stability without requiring external reinforcements
2Stability of the object's composition
If glass scrims or longitudinal filaments are embedded to reinforce the core, then dimensional stability is improved, but production cost increases
Solution Approach 1:
The invention removes the need for separate reinforcement materials and their associated manufacturing steps, simplifying production and reducing costs while maintaining dimensional stability through the core non-woven fabric's inherent properties
Solution Approach 2:
The invention uses a simple bonded non-woven fabric that can be produced cost-effectively through standard spinning and bonding processes, replacing expensive reinforcement materials like glass scrims and filaments
3Ease of manufacture
If the core is made without reinforcement, then manufacturing is simplified and cost is reduced, but dimensional stability deteriorates causing shrinkage and deformation
Solution Approach 1:
The invention modifies the parameters of the bonded non-woven fabric by ensuring it possesses a specific latent shrinkage force that actively counteracts strains during heat treatment, thereby achieving dimensional stability without requiring reinforcement
Solution Approach 2:
The bonded non-woven fabric serves its own reinforcement function through its inherent latent shrinkage force, eliminating the need for separate reinforcement components and simplifying manufacturing while maintaining dimensional 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 solution provides high thermal dimensional stability, preventing shrinkage and deformation, ensuring consistent product quality, reducing material waste, and simplifying production while maintaining the core's weight and functionality, thus eliminating the need for costly reinforcements.
Implementation Method 1
which has a latent shrinkage force which counteracts the strains which arise in those subsequent treatment operations in the course of the manufacture of composite materials which take place under heat
Implementation Method 2
a reinforcement-free, bonded non-woven of polyester filaments which is bound by a binder
Implementation Method 3
produced through the spun-bond process, mechanical needle-punching, and thermal bonding
Data Source
AI summary
A polyester filament nonwoven ply is suitable for roofing and roof-sealing webs and has a latent shrinkage force which counteracts drafting forces which may subsequently occur as the result of stresses or during thermal processing operations. The roofing webs thus remain dimensionally stable even when exposed to heat. The shrinkage force is obtained according to the claimed process by drafting the ply accordingly in a drafting mechanism arranged after a dryer.