Fastener Stringer Color Consistency After Wear

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The external appearance of fastener elements changes significantly due to the wear off of plated or metal-oxide layers as the number of slider trips exceeds 2000 or 3000 times, leading to exposure of the metal base member.

Innovation Solution

A fastener stringer design featuring a metal base member with intermediate metal layers and a surface resin layer of the same color tone, where the surface resin layer is designed to wear off, exposing a matching color tone metal layer, thereby maintaining the initial appearance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If a plated layer or metal-oxide layer is formed on the metal base member to achieve desired color, then the external appearance is improved, but the layer wears off after 2000-3000 slider trips causing appearance degradation

Engineering Contradiction:
Improveexternal appearanceVSAvoidappearance consistency
Core Design Contradiction:
ShapeVSReliability

Solution Approach 1:

The patent applies preliminary action by pre-forming an intermediate metal layer with the same color tone as the surface resin layer before applying the resin coating. This ensures that when the resin layer wears off after repeated slider trips, the exposed intermediate layer maintains color consistency, preventing appearance degradation and eliminating the need for corrective measures.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent applies local quality by creating a layered structure where the intermediate metal layer possesses specific color properties that match the surface resin layer. This localized color matching at the interface between layers ensures that wear exposure does not create visible contrasts, thereby maintaining overall appearance consistency throughout the product lifecycle.

Inventive Principle:
Principle #3Local quality

2Reliability

If a thick surface resin layer is used to prevent metal base member exposure, then appearance consistency is improved, but manufacturing complexity increases

Engineering Contradiction:
Improveappearance consistencyVSAvoidmanufacturing process
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-forming the intermediate metal layer with appropriate thickness and color properties before applying the surface resin layer. This preliminary preparation allows for a thinner, more manageable resin coating while ensuring that any exposure due to wear will reveal a color-matched intermediate layer, thereby maintaining appearance consistency without requiring excessive resin thickness or complex manufacturing controls.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3375317B1Fastener stringer, method for manufacturing same, and slide fastener
Publication Date: 2021.06.30 YKK CORP
  • EP3375317B1 patent drawingFigure 1
  • EP3375317B1 patent drawingFigure 2~3
  • EP3375317B1 patent drawingFigure 4~5

AI summary

A fastener stringer (30) includes: a fastener tape (10); and a plurality of fastener elements (20) attached to a side-edge portion of the fastener tape (10). The fastener element (20) includes: a metal base member (21); a single layered or multi layered surface resin layer (22) formed on the metal base member (21); and one or more intermediate metal layers (23) interposed between the metal base member (21) and the surface resin layer (22). The one or more intermediate metal layers (23) include an exposure metal layer (26) that will be exposed by at least a partial removal of the surface resin layer (22). The surface resin layer (22) and the exposure metal layer (26) are made of material having the same color tone.