Apparatus and process for making a tape useful as a tire cap ply

Abstract

An apparatus and process are used to make tape which can be used as cap plies, breakers and reinforcement in the carcass of tires. The tape is made by dipping a plurality of single end cords in a solvent-based cement. The cords are converged before entering the dip pan so that they are fixed in a single plane when they are dipped. The cement, which comprises solvent and an elastomeric composition, is dried so that the majority of the solvent evaporates. The elastomeric composition remains, encapsulating the cords, thereby forming the tape.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to an apparatus and a process for making tape which can be used as cap plies, breakers and reinforcement in the carcass of tires. [0003] 2. Description of the Related Art [0004] The tire industry has long had considerable interest in belted tire constructions for reinforcing tires. An example of a tire reinforcement is described in U.S. Pat. No. 3,720,569 to Kimble. This reinforcement is formed by passing a plurality of cords in the desired spaced relationship through an extruder. The cords may be coated with a rubber latex in a multiple dip operation to form a unitary strip. Such reinforcement constructions may offer the advantage of better road stability and longer tread life in both radial and bias ply constructions. However, such constructions are subject to belt-edge separation failures because the adhesion of the reinforcement to the tire rubber is inadequate. [0005] Cap plies tha...

AI Technical Summary

Benefits of technology

[0009] In addition, the process of the present invention is not as labor intensive as the slit rubberized fabric process of the prior art, as it does not involve slitting of fabric. In addition, it is not as capital intensive as the slit rubberized fabric process, as it does not require a calender roll. Moreover, the process of the present invention avoids the potential for error in that it does not have a slitting step, and hence the possibility of non-uniformity due to the possible varying number of single end cords in each strip is virtually eliminated. Also, since there is no slitting step in the process of the present invention, no edge fray is created and there are no cut cords on the edges of the tape. Thus, the process of the present invention produces less scrap than the slit rubberized fabric process. Finally, the overall weight of the tire could be reduced, since there is no need to add rubber to ensure good adhesion of the fabric to the tire rubber.

Problems solved by technology

However, such constructions are subject to belt-edge separation failures because the adhesion of the reinforcement to the tire rubber is inadequate.

In addition, there is a limitation on the extension of the belt, since the cap ply is applied over the belt.

These are inherently high cost / labor intensive procedures.

Because of the slitting step, there may be cut cords on the edges of the tape, which may create edge fray.

Consequently, such a process produces a fair amount of scrap material.

Moreover, the tape so produced can be non-uniform, due to the possible varying number of single end cords in each strip.

With each step the potential for error and the additive variances requires allowance for excessive tolerances in the tire building process.

Finally, the addition of rubber to ensure good adhesion of the fabric to the tire rubber adds to the overall weight of the tire.

Moreover, the tape itself is still dependent on a rubber compounding step and the addition / application of rubber as a means to ensure good adhesion to the tire rubber compounds, hence increasing weight and cost.

Images