Tire vulcanization/retreading system using autoclave with electromagnetic induction heating

Abstract

Tire vulcanizing / retreading and de-vulcanization system including an autoclave and heating based on an induction system, which will lead to vulcanization or de-vulcanization of a tire.

Description

CROSS REFERENCE TO RELATED APPLICATION[0001]This application is a divisional of U.S. patent application Ser. No. 13 / 257,444, filed Dec. 6, 2011 the entire content and disclosure of which is incorporated herein by reference.FIELD OF THE INVENTION[0002]The present invention in the field of tire and tire retreading industry using vulcanizing process of elastomeric material.BACKGROUND OF THE INVENTION[0003]The tire construction concept, radial tires have a complex structure, as seen in FIG. 1, which includes the following key components:[0004]Tread (P1): area where the tire touches the ground; Shoulder (P2): Transition area from the tread to the tire sidewalls; Sidewalls (P3): area that supports the tire structure; Bead (P4): area of contact and fixation of the tire with the wheel for assembly; Casing ply (P5): the steel or textile structure that conforms the tire. In radial tires it is 100% metal or mixed, textile with metal, with differentiated construction of the diagonal tire, which...

AI Technical Summary

Benefits of technology

The patent describes a new way of vulcanizing tires that improves productivity without compromising quality. By using an induction technology, the process does not require large heating equipment or long pre-heating stages. Instead, the tire is heated for a shorter time, reducing energy consumption and allowing for re-use of the tire casing. The technology also prevents surface oxidation and deformation of the tire at the end of the process. Overall, the technology is more efficient, eco-friendly, and results in a high-quality final product.

Problems solved by technology

In cargo loading, machines and agricultural fields, the casing structure corresponds to a range of up to 82% of the casing structure, meaning that lack of reutilization is a major waste.

Vulcanization starting too quickly is not recommended in most cases because it interferes with the process safety.

The level of complexity required by the installation before getting to the actual operation involved in tire vulcanization and in retreading by vulcanization is relatively high, and variable in errors and decisions involved are often higher than the technical capacity of the final user involved, particularly in the retreading sector with unskilled labor.

Even in relatively large companies, the levels of success, efficiency and sustainability are quite low.

a) Boiler Efficiency, as Determined by the Following Parameters:a1. Temperature of gases (chimney temperature);a2. Fuel specifications;a3. Ambient air temperature;a5. Losses by radiation and convection;

b) Losses in Steam Piping;b1) Improper layout;b2.) Wrong sizing of pipes;b3.) Qualification of materials;b.4) Insufficient insulation;b.5) Lack of maintenance in piping;b.6) Improper operation;

c) Losses Associated to Tire Vulcanization Equipment:c.1) Poorly sized installation;c.2) Deficient or unsuitable insulation;c.3) Poor quality accessories such as valves, controllers, etc.;c.4) Wrong sizing of equipment;c.5) Lack of maintenance;c.6) Improper operation.Consolidation of the critical analysis of the conventional vulcanization process: an analysis of the aspects that compromise vulcanization effectiveness allows us to state that, among the countless aspects listed, waste of energy is of great relevance.Energy consumption is always high since in order to transfer heat by means of the aforementioned methods, the heating elements invariably operate at a very high temperature so heat exchanges can take place between the bodies within a desirable time length.Currently all autoclave heating systems available in the market work with the convection and conduction principle, in which heat exchange between tire components occurs. To do so, transformations and changes in state of the materials involved are required. This causes great losses in efficiency because of the machines, labor, process, materials, the environment, etc. Convection heat exchange is really an expensive process due to the difficulties to control energy waste.From the viewpoint of the tire physical structure, using vulcanization by convection and conduction is extremely slow. The pre-molded material, duly applied on the tread, undergoes slower vulcanization, since vulcanization takes place by irradiation of the outer surface of the tire and of the pre-molded, the thickness of which varies between 12 and 25 mm, thus forcing heat to penetrate this poor heat-conducting material. This slows down vulcanization and causes great inaccuracy. This traditional concept requires long heating time, i.e., above 180 minutes (3 hours) and, as a consequence, it causes low productivity in retreading.

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