Slide Fastener Tape Structure for Concealment and Insert Fitting

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Solution Overview

Problem

The existing slide fasteners face issues with the blocking of gates during injection molding due to the formation of thick core portions at the ends of fastener tapes, making it difficult to insert stoppers or separating inserts, which affects the concealing property and appearance.

Innovation Solution

A slide fastener design with first and second fastener tapes having arch-shaped ends that are either in close contact or separated, allowing for the attachment of stoppers and separating inserts, and a manufacturing method that includes spacer formation and cutting steps to ensure seamless integration of these elements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the one width-directional end of the fastener tape is formed long enough to be buckled in an arch shape, then the concealing property of the element row is improved, but the gate is blocked during injection molding and the core portion becomes thick making it difficult to insert stoppers or separating inserts

Engineering Contradiction:

Improveconcealing propertyVSAvoidinjection molding process

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The one width-directional end of the fastener tape is divided into two distinct regions: a first region where the tape is buckled in an arch shape to provide concealing property, and a second region where the tape is separated to allow injection molding and insertion of stoppers/separating inserts. This segmentation resolves the contradiction by allowing each region to serve its specific function without interfering with the other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different portions of the fastener tape are given different structural properties: the first region has an arch-shaped buckled configuration for concealing, while the second region has a separated configuration for manufacturing accessibility. This local differentiation allows the tape to simultaneously achieve both concealing property and ease of manufacture.

Inventive Principle:

Principle #3Local quality

2Reliability

If the one width-directional end of the fastener tape is formed long enough to be buckled in an arch shape, then the concealing property of the element row is improved, but the core portion becomes thick making it difficult to insert into separable pin or retainer pin

Engineering Contradiction:

Improveconcealing propertyVSAvoidinsertion of stopper or separating insert

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The fastener tape end is segmented into a first region for concealing (arch-shaped) and a second region for insertion operations (separated). This segmentation ensures that the thick core portion does not form, maintaining ease of insertion for stoppers and separating inserts while preserving the concealing property in the first region.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The tape structure is locally optimized: the first region maintains arch-shaped buckling for concealing, while the second region is separated to provide appropriate core portion thickness for easy insertion into separable pins or retainer pins.

Inventive Principle:

Principle #3Local quality

3Shape

If the fastener tape ends are brought into close contact to eliminate gaps, then the appearance is improved, but the gate blocking and resin flow issues during injection molding occur

Engineering Contradiction:

ImproveappearanceVSAvoidinjection molding process

Core Design Contradiction:

ShapeVSEase of manufacture

Solution Approach 1:

The fastener tape is divided into a first region where ends are brought into close contact for good appearance, and a second region where ends are separated to prevent gate blocking and allow proper resin flow during injection molding. This segmentation allows both appearance quality and manufacturing ease to be achieved in different portions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the fastener tape are given different configurations: the first region has close contact between ends for aesthetic appearance, while the second region has separated ends to facilitate injection molding by preventing gate blocking and ensuring proper resin flow.

Inventive Principle:

Principle #3Local quality

Data Source

PatentEP4684685A1Slide fastener and method for manufacturing slide fastener

Publication Date: 2026.01.28 YKK CORP

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AI summary

A slide fastener (1) has a first region (A1) in which one width-directional end (10a) of a first fastener tape (10) and one width-directional end (20a) of a second fastener tape (20) are buckled in an arch shape and brought into close contact with each other when first and second element rows (50, 60) mesh with each other, and second regions (A2a, A2b) in which the one width-directional end (10a) of the first fastener tape (10) and the one width-directional end (20a) of the second fastener tape (20) are configured to be separated from each other.