High-Loft Nonwoven Binder for Breathable Shape-Retaining Bra Cups

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Solution Overview

Problem

Existing bra cup padding materials, such as polyurethane foam and fiberfill, face issues like yellowing, stiffness, poor breathability, and fiber migration during washing, which affect comfort and shape retention.

Innovation Solution

A high-loft nonwoven composition using polyester fiberfill combined with an aqueous polyurethaneurea dispersion as a binder, providing flexibility, stretch-recovery, breathability, and color stability, which addresses the deficiencies of conventional binder compositions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If polyurethane foam is used as padding, then shape retention and molding capability are improved, but yellowing occurs due to oxidation and photochemical reaction

Engineering Contradiction:
Improveshape retentionVSAvoidyellowing
Core Design Contradiction:
Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The patent replaces conventional polyurethane foam with a fiberfill padding system that uses shorter-lived, naturally more stable fibers (polyester, polypropylene, acrylic) bound with a polyurethane resin. The fiberfill structure inherently resists yellowing while maintaining shape retention through the binder system, effectively substituting a material prone to degradation with one that is more stable over time.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Temperature

If polyurethane foam is used as padding, then softness and lightness are improved, but breatheability and vapor transmission are worsened

Engineering Contradiction:
ImprovesoftnessVSAvoidpoor breatheability
Core Design Contradiction:
TemperatureVSObject-affected harmful factors

Solution Approach 1:

The patent employs a fiberfill padding structure with inherent porosity and air gaps between fibers, allowing vapor and air transmission. This porous fiber-based structure replaces the denser foam structure, enabling breathability while maintaining softness through the flexible fiber network and appropriate fiber selection.

Inventive Principle:
Principle #31Porous materials

3Stability of the object's composition

If resin binder is applied to fiberfill padding, then shape retention during washing is improved, but stiffness is increased making it uncomfortable

Engineering Contradiction:
Improveshape retentionVSAvoidflexibility
Core Design Contradiction:
Stability of the object's compositionVSEase of operation

Solution Approach 1:

The patent modifies the binder system by using a polyurethane resin with specific molecular weight, flexibility, and curing characteristics. The resin is applied at controlled concentrations and cured under specific conditions to achieve optimal balance between shape retention and flexibility. This parameter optimization allows the binder to hold fibers in place while maintaining the padding's softness and drape.

Inventive Principle:
Principle #35Parameter changes

4Stability of the object's composition

If conventional binder compositions are used, then shape retention is improved, but stretch-recovery properties are lost

Engineering Contradiction:
Improveshape retentionVSAvoidstretch-recovery
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The patent creates a composite structure combining fiberfill materials with a polyurethane resin binder system that provides both binding and elastic recovery properties. The composite of fibers and resin works synergistically to maintain shape while allowing stretch and recovery movements, enhancing comfort and adaptability to body contours.

Inventive Principle:
Principle #40Composite materials

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 results in bra cups that are more breathable, lightweight, moldable, and color-stable, with improved comfort and shape retention after washing, overcoming the limitations of polyurethane foam and fiberfill.

Implementation Method 1

The stabilizer is provided by a polyurethane dispersion. By using the polyurethaneurea aqueous dispersion as a binder for the fiberfill in a high-loft nonwoven structure

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP2215295B1High-loft nonwoven including stabilizer or binder
Publication Date: 2015.07.01 INVISTA TECHNOLOGIES SARL(CH)

AI summary

The present invention is directed to a high-loft nonwoven including a binder or stabilizer including a polyurethaneurea composition that provides flexibility and compression recovery to the nonwoven structure. Included is a polyurethaneurea dispersion as a stabilizer or binder for the short-length fibers which create the high-loft nonwoven structure. The invention is useful as an improved alternative for such things as polyurethane foam in applications such as bra cups.