Bead Core Resin Adhesion via Composite Coating and Injection Molding
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Solution Overview
Problem
The existing manufacturing methods for bead cores, particularly those with a stacked annular structure, face durability issues due to separation of coating resins under lateral forces, compromising the integrity of the tire's bead core.
Innovation Solution
A manufacturing method that involves winding and stacking bead wires coated with a specific thermoplastic resin, followed by hot plate welding or bonding, and subsequent injection molding with a secondary resin to create a solidified outer layer that enhances adhesion and resistance to external forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If coating resins of adjacent stacks are joined by welding or bonding, then the bead core can be manufactured with reduced number of turns, but the coating resins may separate at the interface when large lateral forces act on the tire
Solution Approach 1:
The patent uses a composite material structure where a thermoplastic resin coating is applied on the bead wire, and a rubber material is embedded within this coating. This composite structure allows the thermoplastic resin to provide strong bonding between stacked annular members while the rubber material enhances adhesion and prevents separation under lateral forces, thus resolving the contradiction between productivity and reliability.
Solution Approach 2:
The patent applies different materials with different properties at different locations within the coating layer. The thermoplastic resin provides the primary bonding function for joining stacks, while the embedded rubber material specifically addresses the adhesion problem at potential separation interfaces. This local differentiation of material properties allows each material to perform its specialized function, preventing separation while maintaining manufacturing efficiency.
2Productivity
If a strip member coated with thermoplastic resin is wound and stacked to form annular member, then productivity is improved, but adhesion between coating resins of adjacent stacks is insufficient under lateral forces
Solution Approach 1:
The patent creates a composite coating structure by embedding rubber material within the thermoplastic resin coating. This composite structure combines the high bonding strength of thermoplastic resin for efficient stacking with the superior adhesion properties of rubber that prevents separation under lateral forces, thereby simultaneously achieving high productivity and strong adhesion.
Solution Approach 2:
The embedded rubber material acts as an intermediary within the thermoplastic resin coating, providing enhanced adhesion properties. The rubber material mediates between the thermoplastic resin layers of adjacent stacks, preventing direct separation and improving overall adhesion while allowing the thermoplastic resin to maintain its bonding function for productive manufacturing.
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 results in a bead core with improved durability by increasing the adhesiveness and tensile strength of the resin layers, effectively protecting against lateral forces and maintaining structural integrity.
Implementation Method 1
heating and pressing to bond the bead wires to one another
Implementation Method 2
heating and pressing
Implementation Method 3
injection molding with a secondary resin to create a solidified outer layer
Data Source
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AI summary
A manufacturing method of a bead core of the present disclosure comprises an annular body forming step of winding a strip member formed by coating one or more bead wires with a coating resin to form an annular body, and a resin coating step of coating the annular body formed in the annular body forming step with a resin.