Fastener Stringer Magnetic Stop Part Heat Insulation

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Solution Overview

Problem

Existing fastener stringers face challenges in reliably preventing the separation of magnetic bodies from stop parts, which affects the durability and functionality of slide fasteners.

Innovation Solution

The implementation of a heat-insulating layer between the encapsulating member and the magnetic body, along with an injection-molded portion that shapes to hinder separation, ensures the magnetic body remains securely integrated within the stop part. This includes a design where the encapsulating member is formed with a cup-like portion and a lid, and the injection-molded portion covers the encapsulating member to prevent demagnetization and enhance coupling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a magnetic body is pressed into a recess of a slide-contacting plate or placed in a recess of a base, then the magnetic body can be integrated into the stop part, but the magnetic body may separate from the stop part affecting durability

Engineering Contradiction:
Improvemagnetic body retentionVSAvoidfastener stringer service life
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The encapsulating member is divided into a cup-like portion and a lid that are separately formed and then coupled together. The magnetic body is received in the cup-like portion and sealed by the lid, creating a segmented encapsulation structure that prevents separation while maintaining integration.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The magnetic body is nested within the cup-like portion of the encapsulating member, which is in turn nested within the injection-molded portion. This multi-level nesting structure ensures the magnetic body remains securely positioned and prevents separation from the stop part.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Ease of manufacture

If the encapsulating member is directly injection-molded without a heat-insulating layer, then manufacturing is simpler, but the magnetic body may be damaged by heat during injection molding

Engineering Contradiction:
Improveencapsulating member productionVSAvoidmagnetic body integrity
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

A heat-insulating layer is introduced as an intermediary between the magnetic body and the encapsulating member during injection molding. This layer protects the magnetic body from direct contact with hot molten resin while still allowing the encapsulating member to be formed, thus preserving magnetic body integrity without complicating the manufacturing process.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If the encapsulating member is fully enclosed by injection-molded portion, then the magnetic body is protected from demagnetization, but the encapsulating member cannot be separated from the injection-molded portion

Engineering Contradiction:
Improvemagnetic body protectionVSAvoidencapsulating member assembly
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The encapsulating member is segmented into a cup-like portion and a lid that can be separately formed and assembled. This segmentation allows the magnetic body to be securely protected within the cup-like portion while the lid can be separately attached, facilitating easier assembly operations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The magnetic body is pre-positioned in the cup-like portion before the lid is attached and before the injection-molded portion is formed. This preliminary positioning ensures the magnetic body is protected from demagnetization while allowing the encapsulating member components to be assembled in a controlled sequence.

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 solution effectively prevents the separation of magnetic bodies from stop parts, enhancing the durability and reliability of slide fasteners by maintaining magnetic attraction and preventing demagnetization, thus enabling long-term use and improved functionality.

Implementation Method 1

a heat-insulating layer is formed between the encapsulating member and the magnetic body

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 2

maintaining magnetic attraction

Methodology Applied
Scientific EffectMagnetic attraction: Magnetism

Data Source

PatentEP4029399B1Fastener stringer and method for manufacturing same
Publication Date: 2023.10.25 YKK CORP
  • EP4029399B1 patent drawingFigure 1
  • EP4029399B1 patent drawingFigure 2
  • EP4029399B1 patent drawingFigure 3

AI summary

Fastener stringer (2n,2m) includes a fastener tape (4n,4m) provided with a fastener element (3n,3m); and a stop part (5n,5m) arranged at an end of the fastener tape (4n,4m). The stop part (5n,5m) includes: a magnetic body (30n,30m); an encapsulating member (40n,40m) encapsulating the magnetic body (30n,30m); and an injection-molded portion (50n,50m) that at least partially covers or surrounds the encapsulating member (40n,40m) encapsulating the magnetic body (30n,30m). At least the encapsulating member (40n,40m) hinders heat from being transferred to the magnetic body (30n,30m) while the injection-molded portion (50n,50m) is formed.