Spray Bleaching of Cellulosic Fabrics With Low Water Uniformity

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Solution Overview

Problem

Conventional bleaching methods for cellulosic greige fabrics require large amounts of water and chemicals, lack uniformity on both fabric surfaces, and necessitate complex handling and positioning procedures, which increase time and labor.

Innovation Solution

A spray bleaching method using a formulation comprising a wetter, hydrogen peroxide, caustic, stabilizer, and optical brightener, applied uniformly to both sides of the fabric through an in-line spray head with adjustable nozzles, reducing water consumption and eliminating the need for controlled environments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If conventional jet vessel bleaching is used, then fabric can be bleached, but large amounts of water are required (liquor ratio up to 10:1)

Engineering Contradiction:
Improvewater consumptionVSAvoidbleaching efficiency
Core Design Contradiction:
Quantity of substanceVSProductivity

Solution Approach 1:

The patent applies hydraulic spray technology to deliver bleach formulation directly onto the fabric surface through spray heads, replacing the conventional jet vessel immersion method. This hydraulic application system reduces water consumption by applying bleach as a controlled spray rather than submerging fabric in large volumes of liquor, directly addressing the water consumption vs. productivity contradiction

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The patent changes the physical state and application parameters of the bleach delivery system from immersion (jet vessel) to spray application. By modifying the delivery method and controlling spray parameters (pressure, nozzle configuration, application rate), the system achieves effective bleaching with dramatically reduced liquor ratios while maintaining productivity

Inventive Principle:
Principle #35Parameter changes

2Quantity of substance

If spray bleaching is used, then water consumption is reduced, but uniform bleaching on both sides of fabric is difficult to achieve

Engineering Contradiction:
Improvewater consumptionVSAvoidbleaching uniformity
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The patent segments the fabric treatment process by addressing each side of the fabric separately with dedicated spray heads. The in-line spray system positions nozzles to spray one side of the fabric while the fabric passes through, ensuring uniform coverage on the sprayed side without requiring the fabric to be flipped or repositioned, thus achieving uniformity while maintaining low water consumption

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The fabric's own motion through the in-line spray system serves the bleaching function. The fabric passes through the spray zone in its normal production flow, receiving uniform bleach application without requiring external positioning devices, controlled environments, or manual intervention to maintain tautness, thereby achieving uniformity with minimal water

Inventive Principle:
Principle #25Self-service

3Reliability

If conventional bleaching processes are used, then fabric can be bleached, but complex handling and positioning procedures are required

Engineering Contradiction:
Improvebleaching qualityVSAvoidhandling complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the bleaching operation with the fabric's normal production flow in an in-line system. The spray bleaching is integrated into the existing fabric handling line, eliminating separate handling steps for positioning and repositioning fabric. The bleach application occurs during normal fabric transport without requiring additional positioning equipment or controlled environment chambers, thus maintaining reliability while reducing complexity

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The in-line spray system serves multiple functions simultaneously: it applies bleach uniformly, maintains fabric motion control through the existing production line, and integrates with standard fabric handling infrastructure. This multi-functionality eliminates the need for specialized positioning devices and controlled environment chambers, reducing device complexity while ensuring reliable bleaching quality

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 method achieves uniform bleaching with significant water savings, reducing the liquor ratio from 10:1 to 0.03:1 to 0.09:1, and allows for rapid changeovers between bleaching and dyeing processes, while maintaining high fabric whiteness and efficiency.

Implementation Method 1

hydrogen peroxide, caustic, stabilizer, and optical brightener

Methodology Applied
Scientific EffectOxidation: Oxidation

Data Source

PatentUS8404628B1Method for spray bleaching cellulosic fabrics
Publication Date: 2013.03.26 HBI BRANDED APPAREL ENTERPRISES LLC

AI summary

A method is provided for spray bleaching cellulosic fabrics. A bleaching composition comprises a wetter, hydrogen peroxide, a caustic, a stabilizer, an optical brightener, and water. The bleaching composition is sprayed on at least one surface of the cellulosic fabric, subjected to steam to fix the bleaching composition to the fabric, and rinsed to remove any residual bleaching composition.