Tire Tread Coextrusion With Buried Reinforcing Inserts at Controlled Depth
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing coextrusion installations struggle to produce complex tire treads with freely adjustable shapes, positions, and dimensions for underlays, sculpture blocks, and circumferential reinforcements using distinct elastomeric mixtures, while maintaining operational simplicity and reliability.
Innovation Solution
A coextrusion installation with a multi-port extrusion head and receiving surface that allows for the simultaneous extrusion of multiple elastomeric mixtures, featuring pre-scrapers and scrapers to create and maintain burial trenches for inserting a third elastomeric mixture as circumferential reinforcement, enabling precise positioning and composition freedom for the different tread components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a traditional coextrusion tool is used to produce treads with circumferential reinforcements, then the reinforcement can be formed in one piece with the underlayer, but the shapes, implantation positions and dimensions of the reinforcements cannot be freely adjusted
Solution Approach 1:
The extrusion head is divided into multiple independent portions (first, second, and third head portions) that can be independently controlled and positioned. Each head portion extrudes a different elastomeric mixture, allowing independent adjustment of the underlayer, tread blocks, and circumferential reinforcements. This segmentation enables free adjustment of shapes, positions, and dimensions of each component without redesigning the entire tooling system.
Solution Approach 2:
The invention introduces a vertical dimension of control by positioning the third head portion (extruding circumferential reinforcements) above the first two head portions (extruding underlayer and tread blocks). This vertical stacking allows the reinforcements to be deposited at different heights and positions within the tread structure, enabling free adjustment of implantation positions and dimensions in three-dimensional space.
2Adaptability or versatility
If multiple elastomeric mixtures are extruded simultaneously to form complex tread structures, then the functional requirements can be met, but the operational reliability and simplicity are compromised
Solution Approach 1:
The extrusion head is segmented into independent portions, each responsible for extruding a specific elastomeric mixture. This segmentation allows each portion to be optimized for its specific material and function, improving operational reliability. The first head portion extrudes the underlayer mixture, the second head portion extrudes the tread block mixture, and the third head portion extrudes the reinforcement mixture, ensuring consistent and reliable extrusion of each component.
Solution Approach 2:
The first and second head portions extrude the underlayer and tread blocks before the third head portion extrudes the circumferential reinforcements. This preliminary action ensures that the base structure is already in place and stable before the reinforcements are added, maintaining operational simplicity and reliability. The sequential extrusion process prevents destabilization or deformation of the reinforcement during the extrusion process.
3Ease of manufacture
If the circumferential reinforcement is formed with the underlayer in one piece, then the production process is simplified, but the reinforcement cannot be positioned at optimal depths within the tread blocks
Solution Approach 1:
The first and second head portions extrude the underlayer and tread blocks in advance, creating a stable base structure. Only after this preliminary action is complete does the third head portion extrude the circumferential reinforcements at the optimal depth within the tread blocks. This preliminary action ensures both ease of manufacture and precise positioning of the reinforcements.
Solution Approach 2:
The third head portion is positioned vertically above the first two head portions, allowing the circumferential reinforcements to be deposited at different vertical depths within the tread blocks. This vertical dimension of control enables precise positioning of the reinforcements at optimal depths while maintaining a relatively simple horizontal extrusion process.
Data Source
Figure 1~10
Figure 3
Figure 4~5
AI summary
The invention relates to a coextrusion installation (1) intended to create a profiled element (2) intended to form a tyre tread, by extruding an underlayer (12) made of a first elastomer compound (M1), an overlayer made of a second elastomer compound (M2) for forming tread pattern blocks (22), and inserts (33) made of a third elastomer compound (M3), the installation comprising pre-scrapers (13) followed by scrapers (23) for recessing embedding trenches (14), injectors (31) for injecting an insert (33) at the bottom of each embedding trench (14), and then a covering wall (34) which allows the flows (F1_M1, F2_M2) of second elastomer compound (M2) to merge, refilling the embedding trench (14) in question and covering the corresponding insert (33) so as to embed the insert (33) at a predetermined embedding depth (P31).