Tire Mold Vacuum Closure Without Vent Holes or Surface Spew
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Solution Overview
Problem
Conventional tire molding processes result in spews due to venting passages, which are costly, time-consuming, and require frequent maintenance, and existing vacuum technologies are inefficient in removing air from tire molds without vent holes.
Innovation Solution
A tire molding process that involves creating radial and axial clearances in the tire mold before vacuum application, allowing complete evacuation of air from the mold cavity without the need for vent holes, using movable sidewall mold plates and tread segments with retainer tees for sliding engagement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If venting passages are provided in the tire mold to remove air during curing, then air can be vented from the mold cavity, but spews protrude from the tire surface and appearance is degraded
Solution Approach 1:
The patent applies vacuum evacuation before mold closure to remove air from the mold cavity in advance. The vacuum container creates a vacuum atmosphere around the green tire before the mold is fully closed, preventing air from being trapped during the curing process. This preliminary air removal eliminates the need for vent passages that would otherwise create spews on the tire surface.
Solution Approach 2:
The patent creates a vacuum environment (inert atmosphere without air) within the mold cavity during curing. By evacuating air before closure and maintaining vacuum conditions, the curing process occurs in an air-free environment, preventing air entrapment and subsequent spew formation while preserving tire surface appearance.
2Shape
If sophisticated venting devices or channels are provided in each mold segment to avoid spews, then tire appearance is improved, but manufacturing cost and time increase significantly
Solution Approach 1:
The patent extracts the air removal function from the mold structure itself by introducing an external vacuum container system. Instead of incorporating complex venting devices or channels within each mold segment, the air evacuation function is taken out and performed by a separate vacuum system that creates a vacuum atmosphere before and during curing, simplifying mold manufacturing while avoiding spews.
Solution Approach 2:
The vacuum container acts as an intermediary system between the mold and the air removal function. Rather than modifying the mold structure with complex venting devices, the vacuum container mediates the air evacuation process by creating a vacuum environment that passively draws air out of the mold cavity through existing seal interfaces, eliminating the need for sophisticated venting channels.
3Object-generated harmful factors
If venting passages are provided in the tire mold, then air can be vented during curing, but frequent cleaning and maintenance are required due to blocked passages
Solution Approach 1:
The patent removes the venting function from the mold structure by using an external vacuum container system. This extraction eliminates the need for vent passages within the mold segments that would require cleaning and maintenance. The vacuum system handles air removal through seal interfaces that do not require disassembly or cleaning of internal passages.
4Shape
If vacuum is applied before mold closure to remove air, then spews are reduced or eliminated, but the mold must be made airtight requiring sophisticated sealing
Solution Approach 1:
The vacuum seals serve multiple functions: they seal the vacuum container to the mold, enable vacuum evacuation of air, and maintain the airtight environment during curing. By making the seals multi-functional, the system achieves effective air removal and airtight sealing without requiring separate complex sealing mechanisms, reducing overall device complexity.
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 air from the tire mold cavity, reducing or eliminating the need for vent holes, thereby improving tire appearance and reducing maintenance costs.
Implementation Method 1
drawing a vacuum on the mold cavity while the tire mold is in the second intermediate position
Data Source
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AI summary
A molding process for molding a tire within a tire mold (10) is disclosed. The tire mold (10) has movable elements to bring the tire mold into an open and into a closed position. The tire mold includes a first and second sidewall mold plate (20, 22) and a plurality of tread mold segments (12) cooperating with the sidewall mold plate (20, 22) to form a tire mold cavity (24). The process comprises arranging an uncured tire (36) in the tire mold (10) in the open position; bringing the tire mold (10) from the open position into a first intermediate, partially closed position wherein the plurality of tread mold segments (12) occupy a substantially final axial position but remain separated radially from the uncured tire (36) by a radial clearance (38); establishing an axial clearance (40) between the uncured tire (36) and at least one of the first and second sidewall mold plates (20, 22) so as to bring the tire mold (10) into a second intermediate, partially closed position; drawing a vacuum on the mold cavity (24); bringing the tire mold (10) from the second intermediate position back into the first intermediate position or into a third intermediate position by axially moving the at least one of the first and second sidewall mold plates (20, 22); and moving the tread mold segments (12) radially inwardly and bringing the tire mold into the closed position. Also, a method for closing a tire mold for curing rubber-based pneumatic or non-pneumatic tires is disclosed.