Tyre Curing Mould With Seam-Cutting Strips for Rubber Burr Removal

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Solution Overview

Problem

Existing tire manufacturing molds suffer from rubber burrs forming due to gaps between molding elements, which affect tire quality and appearance, and existing solutions face premature wear or failure due to thermal expansion and contact pressure.

Innovation Solution

Incorporating cutting means on the edges of molding elements that cut the flash or burr when the mold opens, maintaining a narrow gap to prevent deterioration and ensuring efficient burr removal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the gap between molding elements is reduced to prevent rubber insinuation, then burr formation is prevented, but contact surfaces wear faster due to increased contact pressure

Engineering Contradiction:
Improveburr formationVSAvoidmolding element durability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The mold is divided into multiple sectors with contact surfaces and non-contact surfaces. The contact surfaces allow controlled movement and air evacuation, while non-contact surfaces prevent rubber insinuation. This segmentation enables the mold to accommodate wear without forming burrs.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different surfaces of the molding elements have different properties: contact surfaces are smooth for movement, while non-contact surfaces have controlled roughness (50-200 μm) to prevent rubber adhesion. This local differentiation allows the mold to function effectively despite wear.

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If contact surfaces are allowed to move closer due to wear, then manufacturing tolerance is maintained, but non-contact surfaces deteriorate prematurely due to increased contact pressure

Engineering Contradiction:
Improvegap consistencyVSAvoidnon-contact surface life
Core Design Contradiction:
Manufacturing precisionVSDuration of action of stationary object

Solution Approach 1:

The roughness parameter of non-contact surfaces is specifically controlled (50-200 μm) to create a balance: rough enough to prevent rubber adhesion, but manageable under increased contact pressure. This parameter optimization extends the life of non-contact surfaces.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The wear of contact surfaces, which would normally be harmful, is converted into a benefit by allowing controlled movement that maintains the narrow gap. This controlled wear prevents the formation of larger gaps that would cause burrs, while the non-contact surfaces protect against premature deterioration.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Productivity

If non-contact surfaces are made rougher to prevent rubber adhesion, then air evacuation is improved, but contact pressure increases causing premature matting

Engineering Contradiction:
Improveair evacuation efficiencyVSAvoidsurface roughness integrity
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The roughness of non-contact surfaces is optimized to a specific range (50-200 μm). This parameter range provides sufficient air evacuation channels while limiting the contact pressure increase that would cause premature matting. The controlled roughness balances air evacuation needs with surface durability.

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

Effectively removes rubber burrs during mold opening, maintaining tire quality and extending the life of molding elements by preventing premature wear.

Implementation Method 1

During curing, the non-contact surfaces of two adjacent sectors move closer together under the effect of their thermal expansion so as to bear against each other

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP4200127B1Curing mould for a tyre, comprising means for cutting a rubber mould seam
Publication Date: 2025.08.13 MICHELIN & CO (CIE GEN DES ESTAB MICHELIN)
  • EP4200127B1 patent drawingFigure 1~3

AI summary

Curing mould (10) for a tyre, comprising: a plurality of circumferentially distributed sectors (18) which are intended to mould the tread band of the tyre, at least one thin strip (40) for moulding a notch in the tread band, the thin strip extending over two adjacent sectors (18) in such a manner that the thin strip comprises a portion (40a, 40b) on each of the two sectors, the two portions of the thin strip being separated, when the mould is in the closed position, by a space (26) generating a mould seam when a tyre is cured, the portions of the thin strip comprising cutting means (38) which can cut away the mould seam when the mould is opened.