Razor Skin Engaging Member Gradient Polymer Leaching

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Solution Overview

Problem

Existing skin engaging members in razor cartridges exhibit non-uniform deposition rates of water soluble shaving aids and wastefulness due to incomplete leaching from water insoluble matrices.

Innovation Solution

A method involving a precursor with a first water soluble polymer in a matrix of a water insoluble polymer, where a powdered second water soluble polymer is mechanically pressed into the surface region to create a gradient, ensuring higher polymer content closer to the surface for enhanced leaching.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If water soluble shaving aid is dispersed in water insoluble matrix, then the skin engaging member maintains structural integrity during use, but the deposition rate of shaving aid onto skin becomes non-uniform and leaching is incomplete

Engineering Contradiction:
Improvestructural integrity of skin engaging memberVSAvoiduniformity of deposition rate
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The patent applies local quality by creating a gradient distribution of water soluble polymer content within the skin engaging member. The concentration varies from the outer surface toward the interior, with higher content near the surface to ensure uniform and complete leaching during use, while maintaining structural integrity through the water insoluble matrix throughout the component.

Inventive Principle:
Principle #3Local quality

2Productivity

If water soluble shaving aid is leached from water insoluble matrix, then the shaving aid is delivered to skin, but some matrices do not permit complete leaching resulting in waste

Engineering Contradiction:
Improvedelivery efficiency of shaving aidVSAvoidwaste of water soluble shaving aid
Core Design Contradiction:
ProductivityVSLoss of substance

Solution Approach 1:

The patent employs parameter changes by modifying the concentration gradient of water soluble polymer throughout the skin engaging member. By controlling the distribution parameters (higher concentration at outer surfaces, lower toward interior), the formulation ensures complete leaching of all water soluble shaving aid to the skin during normal use, eliminating waste while maintaining efficient delivery.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If water soluble polymer undergoes heat cycle during molding or extrusion, then the precursor is formed, but molecular degradation and scission occur

Engineering Contradiction:
Improveformation of precursorVSAvoidmolecular integrity of water soluble polymer
Core Design Contradiction:
Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The patent applies preliminary action by incorporating the water soluble polymer into the water insoluble matrix before the matrix undergoes heat processing during molding or extrusion. This sequence protects the water soluble polymer from direct exposure to high temperatures that would cause molecular degradation, while still allowing complete formation of the precursor structure.

Inventive Principle:
Principle #10Preliminary action

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

This approach results in a beneficial deposition rate of water soluble shaving aids during use, preventing molecular degradation and ensuring efficient leaching without wastage.

Implementation Method 1

The second water-soluble polymer is mechanically pressed (e.g. by a roller) to embed the second water soluble polymer into the upper surface region

Methodology Applied
Scientific EffectMechanical pressing: Mechanical Force

Implementation Method 2

the press tool, e.g. the roller can be heated to a surface temperature between about 100C and about 250C, preferably about 175C

Methodology Applied
Scientific EffectThermal heating: Heating

Implementation Method 3

Upon exposure to water, the water soluble shaving aid leaches from the matrix of the skin engaging member onto the skin

Methodology Applied
Scientific EffectLeaching: Diffusion

Data Source

PatentEP2988909B1Skin engaging member for a razor cartridge
Publication Date: 2019.01.09 EDGEWELL PERSONAL CARE BRANDS LLC
  • EP2988909B1 patent drawingFigure 1~2
  • EP2988909B1 patent drawingFigure 3~4
  • EP2988909B1 patent drawingFigure 5~5A

AI summary

A skin engaging member of a razor cartridge is formed from a precursor of a matrix of a first water soluble polymer and a water insoluble polymer. The precursor includes an upper surface region. A powdered second water soluble polymer is applied to an outer surface of the upper surface region. The second water-soluble polymer is mechanically pressed (e.g. by a roller) to embed the second water soluble polymer in the upper surface region. The upper surface region of the skin engaging member has a locally increased combined first and second water soluble polymer content.