Roof Underlay Grid Needling for Adhesive-Free Bonding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing roof underlays with reinforcing grids face challenges in achieving a strong, adhesive-free connection between the grid and the non-woven fabric, which affects the stability and durability of the roofing material.
Innovation Solution
A roof underlay with a fleece layer and a reinforcement grid where the grid strips are needled to the fleece layer using needles with projections and hooks, introducing fibers into the lattice interstices, and then thermally bonding them, utilizing core-sheath fibers that melt at low temperatures to create a mechanical and intimate bond between the grid and the fleece.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If adhesive is used to connect the grid to the non-woven fabric, then the connection strength is improved, but the complexity of the manufacturing process and the use of chemical substances increases
Solution Approach 1:
The patent replaces the chemical bonding method (adhesive) with a mechanical bonding method (needling). The needling process mechanically interlocks the grid structure with the non-woven fabric by penetrating fibers through both layers, creating a physical connection that eliminates the need for chemical substances and simplifies the manufacturing process.
Solution Approach 2:
The patent creates a composite structure by combining the grid and non-woven fabric through needling, where the two different materials are mechanically integrated into a single functional unit. This composite approach allows the grid and fabric to work together as a unified reinforcement system without requiring additional bonding agents.
2Strength
If the grid strips are made wider to improve stability, then the mechanical strength is improved, but the lattice free space decreases reducing functionality
Solution Approach 1:
The patent applies local quality by concentrating the reinforcement function in the grid strip regions while maintaining open lattice spaces in between. The grid strips provide localized mechanical strength where needed, while the spaces between them preserve functionality for drainage, ventilation, or flexibility. This spatial differentiation allows both strength and functionality to coexist.
3Strength
If needling is performed from the fleece side, then the mechanical connection is improved, but fibers are pushed out requiring additional processing
Solution Approach 1:
The patent extracts the problematic pushed-out fibers from the surface and incorporates them into the grid structure through the needling process. By directing needles from the fleece side, fibers are intentionally pulled out and entangled within the grid openings, where they become part of the mechanical connection rather than defects requiring removal.
4Strength
If thermal bonding is applied to melt core-sheath fibers, then the bond strength between grid and fleece is improved, but the temperature control complexity increases
Solution Approach 1:
The patent utilizes the phase change parameter of core-sheath fibers, where the core material melts at a specific temperature to create bonding. By controlling the thermal process to reach the melting point of the core material, strong bonds form between the grid and fleece without requiring complex temperature profiles, as the phase change itself provides the bonding mechanism.
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 a stable, abrasion-resistant roof underlay with a mechanical clawing connection, ensuring the grid is intimately bonded to the non-woven substrate, offering improved durability and resistance to water while maintaining vapor permeability.
Implementation Method 1
at least some of the fibers of the fleece material have a jacket that melts at low temperatures
Implementation Method 2
the sections of the non-woven fibers introduced into the webs of the fabric are partially melted, so that there is an intimate bond between the webs of the grid and the non-woven substrate
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
Fabric, preferably roofing underlayment comprises a fleece layer (1) and a reinforcing mesh (2) associated with the fleece layer. The grid strips (3) of reinforcing mesh are made of strips which are needle punched to form a contact surface with the fabric layer, and have distance free spaces between the strip with the non-woven layer. An independent claim is also included for manufacturing a fabric, preferably roofing underlayment comprising placing intersecting strips on the fleece layer of a woven and introducing the fleece layer by needles portions of fibers (5) or filaments of the fabric layer into the strips and portions of fibers or filaments of the strip.