Fastener Stringer With Flexible Core Sheet for Airtight Sealing

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Solution Overview

Problem

There is a gap in the market for slide fasteners that offer a balance between cost-effectiveness and sufficient water-tightness or airtightness, as less expensive fasteners have limited water repellency and expensive fasteners provide adequate water-tightness or airtightness.

Innovation Solution

A fastener stringer design featuring a fastener tape with a covering member made of soft material, including a flexible core sheet embedded in the soft material, where one surface of the core sheet is partially exposed, and a sealing portion positioned opposite to the fastener element, supporting the fastener tape and enhancing water-tightness or airtightness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a polyurethane film is laminated onto a fastener tape, then water repellency is improved, but manufacturing cost increases

Engineering Contradiction:

Improvewater repellencyVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent uses a composite structure combining a fastener tape (base fabric) with a polyurethane film layer. This composite material approach allows the fastener to achieve both water repellency and cost-effectiveness by utilizing the low-cost base fabric and adding a thin functional coating layer, rather than using expensive fully-laminated constructions.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent applies a thin polyurethane film onto the fastener tape to provide water repellency. This thin film approach maintains flexibility and allows for cost-effective manufacturing while achieving the required waterproof performance, avoiding the need for thicker or more expensive sealing structures.

Inventive Principle:

Principle #30Flexible shells and thin films

2Reliability

If injection-molded elements are used to create opposing side edges, then water-tightness is improved, but manufacturing cost increases

Engineering Contradiction:

Improvewater-tightnessVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent employs a flexible covering member made of soft material that can be conformally attached to the fastener tape edges. This flexible shell approach creates effective sealing through conformity rather than rigid injection-molded structures, reducing manufacturing complexity and cost while maintaining water-tightness.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The patent changes the material properties by using soft, flexible materials for the covering member rather than rigid injection-molded plastics. This parameter change in material rigidity allows for cost-effective manufacturing while achieving sufficient sealing performance through the soft material's ability to conform to surface irregularities.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If a covering member with sealing portion is added to the fastener tape, then water-tightness is improved, but device complexity increases

Engineering Contradiction:

Improvewater-tightnessVSAvoidstructure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the covering member with the fastener tape into an integrated structure where the soft material covering conformally follows the tape's contours. This merging approach creates a unified sealing system rather than separate components, reducing assembly complexity while maintaining effective water-tightness.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The flexible covering member is designed to conformally follow the fastener tape's shape, creating an integrated sealing system. This flexible shell approach simplifies the overall structure compared to rigid sealing mechanisms, as the soft material naturally adapts to surface irregularities without requiring complex adjustment mechanisms.

Inventive Principle:

Principle #30Flexible shells and thin films

Data Source

PatentUS20250318607A1Fastener stringer and method of producing the same

Publication Date: 2025.10.16 YKK CORP

AI summary

Fastener stringer includes: a fastener tape; a fastener element arranged on a side edge portion of the fastener tape; and a covering member made of soft material and covering the fastener tape, the covering member comprising a sealing portion positioned on an opposite side of the fastener element with respect to the fastener tape in a thickness direction of the fastener tape. The covering member includes a flexible core sheet extending in a longitudinal direction of the fastener stringer. The core sheet is embedded in the soft material such that one surface of the core sheet is at least partially exposed or both surfaces of the core sheet are not exposed.