Annular Seal Joint Molding to Prevent Core Protrusion

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Solution Overview

Problem

Existing manufacturing methods for annular seal materials with a core and outer layer face challenges such as cracking of the outer layer and protrusion of the core in joint portions, leading to high production costs and complexity.

Innovation Solution

A method involving the use of rope-like preforms made from crosslinkable rubber compositions, where a preforming step is followed by two hot pressing steps to create an annular seal material with a core and outer layer, ensuring a stable joint portion and preventing core protrusion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the outer layer portion is inflated during molding, then the outer layer can cover the core material, but the outer layer portion material may break

Engineering Contradiction:
Improveouter layer coverageVSAvoidouter layer integrity
Core Design Contradiction:
Manufacturing precisionVSStrength

Solution Approach 1:

The outer layer portion is pre-formed into a string shape with appropriate dimensions before molding. This preliminary shaping ensures that the outer layer has the correct geometry to cover the core material without requiring excessive inflation during molding, thereby preventing material breakage while achieving complete coverage.

Inventive Principle:
Principle #10Preliminary action

2Strength

If a connecting member is disposed at the seam, then the joint can be strengthened, but the layer configuration at the seam does not have a two-layer structure

Engineering Contradiction:
Improvejoint strengthVSAvoidlayer structure uniformity
Core Design Contradiction:
StrengthVSStability of the object's composition

Solution Approach 1:

The connecting member is integrated with the core material to form a unified joint structure. The connecting member and core material are positioned and bonded together before final molding, creating a seamless joint that maintains the two-layer structure throughout while providing enhanced joint strength through the combined geometry of the connecting member and core.

Inventive Principle:
Principle #5Merging (Combining)

3Manufacturing precision

If the core material is inserted into the cavity before molding, then the outer layer can be formed around it, but the core material may protrude from the gap between the upper and lower outer layers

Engineering Contradiction:
Improveouter layer formationVSAvoidcore material position
Core Design Contradiction:
Manufacturing precisionVSShape

Solution Approach 1:

The core material is pre-positioned within the cavity with的定位 structures or support elements that prevent upward movement during molding. These preliminary positioning measures counteract the tendency of the core material to protrude, ensuring it remains properly positioned while the outer layer forms uniformly around it.

Inventive Principle:
Principle #9Preliminary anti-action

4Ease of manufacture

If the outer layer material is formed into a ribbon and wound around the core, then the outer layer can be applied, but wrinkles occur in the curved portion and feeding becomes difficult

Engineering Contradiction:
Improveouter layer applicationVSAvoidmaterial surface quality
Core Design Contradiction:
Ease of manufactureVSShape

Solution Approach 1:

The outer layer material is supplied as a pre-formed string with optimized cross-sectional dimensions and flexibility parameters. This parameter optimization allows the material to be directly positioned and molded around the core without requiring winding operations, thereby eliminating wrinkle formation while maintaining ease of application through the string's inherent flexibility and dimensional stability.

Inventive Principle:
Principle #35Parameter changes

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

The method effectively suppresses cracking of the outer layer and protrusion of the core in the joint portion, enabling mass production of annular seal materials at a lower cost while maintaining material integrity.

Implementation Method 1

a preforming step of providing one or two or more rope-like preforms comprising an uncrosslinked core made of a crosslinkable rubber composition for a core, and an uncrosslinked outer layer, made of a crosslinkable rubber composition for an outer layer, covering a periphery of the uncrosslinked core; a first hot pressing step of placing the rope-like preform in a first mold to hot press mold a portion other than end portions of the rope-like preform; and a second hot pressing step of contacting two end portions of the rope-like preform with each other and placing the same in a second mold to carry out hot press molding

Methodology Applied
Scientific EffectHot press molding:

Implementation Method 2

an uncrosslinked core made of a crosslinkable rubber composition for a core, and an uncrosslinked outer layer, made of a crosslinkable rubber composition for an outer layer

Methodology Applied
Scientific EffectCrosslinking:

Data Source

PatentEP4501603A1Annular seal member and manufacturing method
Publication Date: 2025.02.05 VALQUA LTD
  • EP4501603A1 patent drawingFigure 1(a)~1(b)
  • EP4501603A1 patent drawingFigure 2
  • EP4501603A1 patent drawingFigure 3a~3b

AI summary

The present invention relates to a method for manufacturing an annular seal material comprising a core and an outer layer covering a periphery of the core, comprising: a preforming step of providing one or two or more rope-like preforms comprising an uncrosslinked core made of a crosslinkable rubber composition for a core, and an uncrosslinked outer layer, made of a crosslinkable rubber composition for an outer layer, covering a periphery of the uncrosslinked core; a first hot pressing step of placing the rope-like preform in a first mold to hot press mold a portion other than end portions of the rope-like preform; and a second hot pressing step of contacting two end portions of the rope-like preform with each other and placing the same in a second mold to carry out hot press molding, in presented order. According to the present invention, provided is a manufacturing method that can mass-produce an annular seal material constituted of a core and an outer layer at low cost.