Intermittent hot water circulation pressure stabilization insulation tyre vulcanization technology

Abstract

The invention discloses an intermittent hot water circulation pressure stabilization insulation tyre vulcanization technology, comprising the following steps: injecting saturated superheated steam to a vulcanizing machine after spotting, injecting primary superheated water without backing, providing internal pressure rapidly to enable a tread rubber material to fill patterns, injecting secondary superheated water and circulating as external pressure steam is entered to heat a green tyre, starting positive vulcanization, stopping the circulation of the secondary superheated water, feeding external pressure steam continuously, carrying out positive vulcanization for a tyre continuously, cycling the secondary superheated water again, feeding external pressure steam continuously, stopping the circulation of the secondary superheated water, keeping the pressure until the vulcanization is finished, stopping the external pressure steam, discharging the external pressure to atmospheric pressure, discharging hot water in capsules and vacuumizing, completing the vulcanization finally and taking the tire out of a mould. The overcure phenomena of carcass and the belt layer are effectively prevented according to the invention. The durability of the tire is enhanced from original 90 hr to over 110 hr. The service life of the tire is prolonged.

Description

technical field [0001] The invention relates to a tire vulcanization process, in particular to an intermittent hot water circulation constant pressure heat preservation tire vulcanization process, which belongs to the field of rubber manufacturing. Background technique [0002] With the development of my country's highways and the improvement of automobile performance, people have put forward higher requirements for the safety and comfort of automobiles, so they have higher requirements for the performance of tires. In particular, the durability and long-distance performance of tires have attracted more attention. This requires not only breakthroughs in structural design of tires, but also the formulation of tire vulcanization processes. In the past, the concept of "better to owe than to owe". [0003] The traditional tire vulcanization process is to pass a certain temperature and pressure medium such as steam into the bladder of the vulcanized tire for a certain period of ...

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Problems solved by technology

According to the actual temperature measurement, the degree of overvulcanization of the local rubber material reaches more than 200%, which will greatly reduce the physical properties of the rubber material and affect the quality of the tire.

[0004] Another vulcanization process adopted by some domestic manufacturers is variable temperature vulcanization process. This vulcanization process directly enters high-pressure saturated steam into the capsule in the early stage. The internal pressure is generally 1.6-1.9MPa, the temperature reaches 190-210°C, and the vulcanization time is 10-15min. , and then changed to 170°C superheated water circulation, continuous vulcanization, stop the cycle at the later stage of vulcanization, commonly known as pressure-holding vulcanization, the time is determined according to the specification, generally ranging from 20-30min, and the temperature gradually drops. The advantage of this method is mainly high production efficiency. However, due to the accumulation of condensed water formed by the early steam in the capsule, it is difficult to completely discharge it from the capsule in time. During the vulcanization process, the temperature of the lower mold is significantly lower than that of the upper mold, and the temperature difference even exceeds 10°C. The temperature difference between the upper and lower molds is relatively large. The vulcanization quality of tires is difficult to guarantee

In addition, due to the low initial internal pressure, which only reaches 1.6-1.9MPa, which is far lower than the normal superheated water pressure of 2.6±0.1MPa, resulting in thick rubber on the shoulder of the tire, resulting in insufficient local pressure, and tends to produce steel wire belts Ply ends are loose, which affects the high speed and durability performance of the tire

And due to the low internal pressure, the qualified rate of the appearance of the finished product will also decrease.

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