Foamed Opacifying Coating for Flexible Light-Blocking Fabrics
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Solution Overview
Problem
Existing light blocking materials, such as blackout curtains, require multiple coating operations and can expose dark opacifying agents like carbon black, leading to unsightly shading and increased manufacturing costs, while also lacking flexibility and launderability.
Innovation Solution
A foamed, opacifying element comprising a porous substrate coated with a dry foamed composition containing porous particles, a binder material, additives, and an opacifying colorant, which minimizes exposure of the opacifying colorant and allows for simpler manufacturing, improved flexibility, and easier laundering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple coating operations are used to achieve light blocking, then light blocking effectiveness is improved, but manufacturing complexity and costs increase
Solution Approach 1:
The patent combines multiple functional layers (light scattering layer and light absorbing layer) into a single integrated foam coating. The foam structure inherently provides light scattering through its cellular morphology, while carbon black particles provide light absorption, eliminating the need for separate coating operations and reducing manufacturing complexity.
Solution Approach 2:
The invention uses a composite foam material that integrates both light scattering properties (through the foam cellular structure) and light absorbing properties (through carbon black particles). This composite approach achieves superior light blocking effectiveness in a single layer, avoiding the need for multiple sequential coatings.
2Reliability
If carbon black is used as opacifying agent, then light blocking effectiveness is improved, but exposure of carbon black leads to unsightly shading and aesthetic problems
Solution Approach 1:
The patent embeds carbon black particles within the foam cellular structure, nesting the light-absorbing agent inside the light-scattering foam matrix. This nested configuration prevents carbon black exposure on the surface while maintaining its light blocking function, as the foam cells encapsulate the carbon black and prevent it from migrating to the surface during sewing or laundering.
Solution Approach 2:
The invention creates different functional zones within the foam structure: the foam cellular structure provides light scattering at the macro level, while carbon black particles provide light absorption at the micro level within the cells. This local differentiation allows the carbon black to function effectively without being exposed aesthetically.
3Reliability
If thick foam coatings are used to block light, then light blocking effectiveness is improved, but weight and material consumption increase
Solution Approach 1:
The patent creates a composite foam structure where the cellular morphology provides light scattering and carbon black particles provide light absorption. This composite approach achieves superior light blocking per unit thickness compared to conventional solid foam, allowing thinner coatings that reduce weight while maintaining effectiveness.
Solution Approach 2:
The invention utilizes the porous foam structure itself as an active light scattering element. The cellular walls and struts of the foam create numerous interfaces that scatter light, enhancing the light blocking effectiveness per unit mass and volume, thereby reducing the overall weight required for effective light blocking.
4Ease of manufacture
If conventional foam coatings are used, then manufacturing is simpler, but flexibility and launderability are poor
Solution Approach 1:
The patent modifies the foam structure parameters, specifically creating a controlled cellular morphology with appropriate cell size and wall thickness. This structural parameter optimization provides inherent flexibility to the coating, allowing it to bend and move with the fabric substrate during laundering while maintaining coating integrity and adhesion.
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 effective light blocking with minimal opacifying colorant exposure, enhanced flexibility, and improved coloration, while reducing manufacturing complexity and costs through a simplified coating process.
Implementation Method 1
aerating the foamable aqueous composition
Implementation Method 2
Evaporative Limited Coalescence (ELC) process
Implementation Method 3
drying it
Data Source
AI summary
A foamable aqueous composition can be used to form foamed, opacifying elements with one or more dry foamed layers. These compositions generally contain: (a) 0.5 to 20 weight % of porous particles comprising a continuous polymeric phase and discrete pores dispersed within the continuous polymeric phase. The porous particles have a mode particle size of 2 to 50 μm; (b) at least 20 weight % of a binder material; (c) 0.1 to 30 weight % of a combination of various additives including dispersants, plasticizers, inorganic or organic pigments and dyes, flame retardants, biocides, fungicides, optical brighteners, tinting colorants, metal flakes, and inorganic or organic fillers; (d) water; and (e) at least 0.001 weight % of an opacifying colorant different from (c). The foamable aqueous composition is suitably aerated, disposed on a porous substrate, dried, and crushed on the porous substrate to form a foamed, opacifying element.