Extruder Splice Bar Grooves for Tire Tread Smear Control

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Solution Overview

Problem

Co-extrusion in tire manufacturing often results in smear, a thin layer of rubber compound appearing at unexpected locations due to flow issues between equipment parts, which is undesirable and affects the quality of multi-layered rubber composites.

Innovation Solution

An extruder assembly with a splice bar and die system that includes grooves on the rear face to capture excess rubber flow, preventing it from leaking into adjacent channels, and forming a 'o ring' seal to reduce or eliminate smear during the co-extrusion process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If co-extrusion is performed to manufacture multi-layered rubber composite, then productivity is improved, but smear appears due to rubber flow at junctions and gaps between equipment parts

Engineering Contradiction:
Improvemulti-layered rubber composite manufacturingVSAvoidsmear
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

A groove is introduced as an intermediary element between adjacent flow channels in the splice bar. This groove acts as a mediator that captures excess rubber flow and prevents it from leaking into adjacent channels, thereby eliminating smear while maintaining the co-extrusion process

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The harmful rubber flow (smear) is extracted and captured in the groove structure. By taking out the excess material that would otherwise cause contamination, the system prevents it from affecting the quality of the multi-layered rubber composite

Inventive Principle:
Principle #2Taking out (Extraction)

2Object-generated harmful factors

If grooves are added to capture excess rubber flow, then smear is reduced, but device complexity increases

Engineering Contradiction:
ImprovesmearVSAvoidsplice bar structure
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The groove is segmented into discrete sections corresponding to different flow channels. Each groove section is independently formed and can be separately inspected or replaced, reducing the overall complexity compared to a complete redesign of the splice bar structure

Inventive Principle:
Principle #1Segmentation

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 solution effectively minimizes smear by creating a fluid-tight seal between channels, ensuring the quality of the multi-layered rubber composite and indicating potential extrusion issues through the status of the grooves, which can be filled with elastomer during inspection.

Implementation Method 1

grooves on the rear face to capture excess rubber flow, preventing it from leaking into adjacent channels

Methodology Applied
Scientific EffectPhysical containment: Physical Containment

Implementation Method 2

forming a 'o ring' seal to reduce or eliminate smear during the co-extrusion process

Methodology Applied
Scientific EffectFluid-tight seal: Physical Containment

Data Source

PatentEP3037241B1Extruder die assembly and method of manufacturing a tire tread
Publication Date: 2020.07.08 THE GOODYEAR TIRE & RUBBER CO
  • EP3037241B1 patent drawingFigure 1A~1
  • EP3037241B1 patent drawingFigure 2
  • EP3037241B1 patent drawingFigure 3

AI summary

An extruder assembly for forming a multi-layered composite is disclosed. The extruder assembly comprises an extruder head assembly (200) having a first and second flow passage (210, 220, 230, 240), a first and second extruder (110, 120, 130, 140) in fluid communication with the respective first and second flow passage (210, 220, 230, 240) and a splice bar assembly (300) comprising a splice bar (302). The splice bar assembly (300) or the splice bar (302) has a first and second passageway (310, 320, 330, 340) extending from a rear side (350) to an outlet side of the splice bar assembly (300) when viewed into to flow direction of the extruder assembly and communicates flow from the first and second passageway (310, 320, 330, 340) to an outlet die (400). The splice bar (302) further comprises at least one groove (370) located on the rear side (350) of the splice bar (302). The at least one groove (370) is positioned between the first and second passageway (310, 320, 330, 340) when viewed onto the rear side (350) of the splice bar (302).