Coated Fibrous Mat Surface Smoothing With Low Coating Weight
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing nonwoven fiberglass mats for gypsum board lack sufficient strength, flexibility, and fire resistance, while also presenting a rough surface and excessive 'stand-up fibers' that cause handling issues and irritation, and are costly.
Innovation Solution
Coated fibrous mats with a smooth surface, achieved by applying a coating comprising clay, inorganic particulates, and a polymer binder, which minimizes coating usage and cost, and features a ratio of clay to limestone, applied using a method that ensures the coating stays mainly on the surface, using a hot, smooth surface for drying to achieve a smooth finish.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a coating is applied to the fibrous mat to smooth the surface and reduce stand-up fibers, then surface smoothness and handling characteristics are improved, but coating weight and cost increase
Solution Approach 1:
The patent applies a coating composition with specific parameter ranges: 5-20% binder, 80-95% filler, and 0.1-5% water-soluble polymer. By optimizing these compositional parameters, the coating achieves smooth surface finish (Ra ≤ 15 microns) while controlling coating weight at 5-20 pounds per thousand square feet, resolving the contradiction between surface quality and material consumption
Solution Approach 2:
The coating is formulated as a composite material combining inorganic fillers (limestone, clay, diatomaceous earth) with organic binders (acrylic, vinyl acetate) and water-soluble polymers. This composite structure provides both the smoothing function and adhesion to the fibrous mat while maintaining controlled coating weight through the inorganic filler matrix
2Strength
If polyester fibers are added to improve mat strength, then strength is improved, but fire resistance deteriorates and cost increases
Solution Approach 1:
The patent uses conventional fiberglass mats with standard resin binders (urea formaldehyde, phenolic, or acrylic) that provide adequate strength without the fire resistance problems of polyester. The coating system provides the additional strength enhancement needed, allowing the base mat to remain fire-resistant while achieving required strength levels through the coating-binder system rather than substituting fire-resistant fiberglass with fire-vulnerable polyester
Solution Approach 2:
The patent modifies the binder composition in the coating to include fire-retardant formulations. The binder system (acrylic, vinyl acetate, or other polymers) is selected and formulated to provide both strength enhancement and maintained fire resistance, changing the chemical parameters of the binding system to simultaneously achieve strength improvement and fire safety
3Ease of manufacture
If conventional coating methods are used, then coating application is simple, but coating penetrates entirely through the mat creating excessive thickness
Solution Approach 1:
The patent introduces a sizing agent or primer layer as an intermediary between the fibrous mat and the final coating. This intermediary layer controls coating penetration by providing a barrier that prevents the coating composition from passing entirely through the mat, while still allowing simple coating application methods to be used. The sizing agent modifies the mat surface properties to control coating absorption and penetration depth
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 coated mats provide improved strength, flexibility, reduced 'stand-up fibers', enhanced fire resistance, and a smoother surface, making them more suitable for handling and decorative applications while lowering costs.
Implementation Method 1
applying a layer of the slurry onto the surface of the fibrous nonwoven mat, bringing the wet coating into contact with a smooth surface, which can be, but not necessarily is, hot, while the coating is still wet, holding the coating in contact with the hot, smooth surface while removing enough water from the coating to make the coating self sustaining
Data Source
AI summary
Coated fibrous mats having properties particularly suited for a facer on gypsum wallboard, foam and other substrates and in laminates of various types, and the method of making the coated mat is disclosed. The mat contains a major portion of non-cellulosic fibers and a minor portion of cured resinous binder. The exposed surface coating has a smoothness of no more than about 15 microns and is comprised of one or more of a clay, a filler and a polymeric binder. The method comprises at least partially drying the coated mat while the exposed surface of the coating is in contact with a smooth surface.