Zip Fastener End Stop Moulding for Seamless Finish

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Solution Overview

Problem

Existing methods for forming end stops on zip fasteners, particularly waterproof ones, often result in unsatisfactory shapes and uneven finishes, especially when using continuous coil coupling elements, which can be uncomfortable and aesthetically unpleasing.

Innovation Solution

The formation of a closed or open end stop by cutting away the fastener tape edges to create an enlarged gap, followed by moulding a compatible material, such as polyurethane, to extend over the tape surfaces and encapsulate the coupling elements, providing a seamless and comfortable finish.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If melting coupling elements is used to form an end stop, then the end stop can be formed without additional components, but the shape of the end stop becomes unsatisfactory and the finish is uneven

Engineering Contradiction:
Improveend stop formation processVSAvoidend stop shape and finish
Core Design Contradiction:
Ease of manufactureVSShape

Solution Approach 1:

The invention separates the coupling element formation from the end stop formation. The continuous coil coupling elements are stopped at a specific point, and a separate molded end stop component is attached to complete the fastener end. This segmentation allows each component to be optimized independently for its specific function.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention combines multiple components (coupling elements, end stop molded piece, and optional reinforcement) into a unified fastener assembly. The end stop molded piece is integrated with the coupling elements through mechanical attachment, creating a combined structure that provides both coupling functionality and a finished end stop.

Inventive Principle:
Principle #5Merging (Combining)

2Ease of manufacture

If a gap is formed by cutting away coupling elements to facilitate end stop attachment, then the end stop can be properly attached, but the manufacturing process becomes more complex

Engineering Contradiction:
Improveend stop attachmentVSAvoidmanufacturing process complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The continuous coil coupling elements are pre-formed and stopped at a predetermined point before the end stop is attached. This preliminary action creates the necessary space for end stop attachment without requiring post-assembly cutting or modification, simplifying the overall manufacturing process.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The end stop molded piece acts as an intermediary component that bridges the gap between the coupling elements and the fastener end. It provides a transition structure that facilitates proper attachment while maintaining the integrity of both the coupling elements and the fastener tape.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If traditional end stop methods are used, then the fastener can be manufactured, but the surface is uneven and visually imperfect

Engineering Contradiction:
Improvefastener manufacturingVSAvoidsurface smoothness and appearance
Core Design Contradiction:
ProductivityVSShape

Solution Approach 1:

The invention changes the physical and chemical parameters of the end stop material through molding processes. The molded piece is formed with specific material properties (flexibility, adhesion characteristics) that allow it to conform to the fastener tape and coupling elements, creating a smooth, even surface finish.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The end stop assembly uses composite construction combining the continuous coil coupling elements (typically polyester or nylon) with a molded end stop piece (typically polyurethane or similar flexible polymer). This composite structure provides both functional and aesthetic benefits, including a smooth finished surface.

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

This method ensures a watertight seal, enhances the grip of the slider, and provides a smooth, even surface, eliminating the discomfort and visual imperfections caused by traditional end stop methods.

Implementation Method 1

moulding a compatible material, such as polyurethane, to extend over the tape surfaces and encapsulate the coupling elements

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP1964486B1Zip fastener end stop
Publication Date: 2016.08.03 YKK CORP
  • EP1964486B1 patent drawingFigure 1µ
  • EP1964486B1 patent drawingFigure 2
  • EP1964486B1 patent drawingFigure 3

AI summary

A zip fastener comprises a pair of tapes and coupling elements along adjacent edges of the tapes. The tapes are partly cut away to form a gap into which an end stop is moulded. The end stop is provided so as to extend along the tape edges away from the fastener coupling elements.