Field of the Invention

The present invention relates to a cap ply reinforcement strip which is ready to use plain woven, which is comprised of cord or twisted yarns as warp and texturized yarn with high linear density as weft, and which is in direct contact with the tread rubber in pneumatic radial tires.

Background of the Invention

In radial tires, it is known that the cap ply reinforcement strip, which is wound on the belt package by making a small angle with the equatorial plane in order to form a cap ply, improves performance of the radial tire especially at high speeds.

Winding nylon 6.6, PET (polyethylene terephthalate), hybrid (Aramide+Nylon 5.5, Aramide+PET) cords spirally as cap ply reinforcement layer on the belt package as strips has been applied for many years by several tire companies in order to improve high speed durability and handling performance in pneumatic radial tires. The said cord strips are obtained by cutting calendered (rubberized) cord fabric in strips or rubberizing parallel single cords in a certain width during extrusion process without weft. In current embodiments, weft yarns with low linear density (100-300 dtex) which do not have any effect on tire performance in cap ply reinforcement strips are used, and the only purpose for using these is to hold the warp yarns or cords together as parallel to each other. The wefts having higher linear density used in some embodiments do not have any effect on the tire performance due to not being able to form any elevation or protrusion on the strip surface since they remain between the leno woven warps(US 7,252,129). Wefts are not used at all in cap ply reinforcement strips prepared with extrusion process. Summary of the Invention

The objective of the present invention is to provide a cap ply reinforcement strip which is obtained by plain weaving the warp cords with the texturized weft yarns with high linear density for pneumatic radial tires.

Another objective of the present invention is to provide a cap ply reinforcement strip which reduces the tread wearing, rolling resistance and braking distance of the pneumatic radial tire by means of the weft yarns comprised therein. Detailed Description of the Invention

"Cap ply reinforcement strip for pneumatic tires" developed to fulfill the objective of the present invention is illustrated in the accompanying figures wherein, Figure 1 is the zoomed, top view of the cap ply reinforcement strip.

Figure 2 is the deformation direction of the tire tread in time of contact with the road in a moving vehicle and the resistance of the weft yarns against this deformation.

Figure 3 is the deformation direction of the tire tread in time of contact with the road in a braking vehicle and the resistance of the weft yarns against this deformation.

The components given in the figure are numbered and the numbers refer to the following: 1 . Cap ply reinforcement strip

2. Texturized weft yarn

3. Warp yarn

Direction of vehicle's movement

L. Direction of tire's rotation

D. Direction of tread's deformation

The inventive cap ply reinforcement strip (1) comprises

a plurality of texturized weft yarns (2) parallel to each other the linear density of which changes between 1400 and 6000 dtex , and

a plurality of warp yarns (3) parallel to each other which are fixed to weft yarns (2) by being plain woven such that they will form an angle between 80 and 100° on horizontal plane to the weft yarns. The inventive cap ply reinforcement strip ( 1) is wound on the belt package on the tire spirally such that there will be a 0 to 5° degree angle with equatorial plane and it is in direct contact with the tread rubber.

The inventive cap ply reinforcement strip (1), which eliminates calendaring and strip preparing stages and enables to reduce rolling resistance of the tire and the fuel consumption by avoiding the requirement for rubber coating thereon, comprises an adhesive dip on its outer surface that is required for tire production process. In the preferred embodiment of the invention, the texturized weft yams (2) and the warp yarns are fixed to each other with adhesive dipping material, and thus a strong bond is formed on contact points of the texturized weft yarn (2) and the warp yarns (3) and warp yarn (3) in the strip ( 1) is prevented from shifting aside and separating. The adhesive material used in one embodiment of the invention is RFL (Resorcinol Formaldehyde Latex). In one embodiment of the invention, texturized weft yarns (2) and the warp yarns (3) are adhered to each other with dipping process for preparing the cap ply reinforcement strip (1 ), and then the strip (1) is optionally cemented with rubber solution, and the physical adherence of its surface is improved.

The texturized weft yarns (2) in the plain woven cap ply reinforcement strip (1) forms regular elevations at contact points with warp yarns (3) on the lower and upper surfaces of the strip (1). These weft elevations are embedded into the tread rubber in the tire and thus increase the resistance of the tread against deformation.

Since the said improved resistance of tread area against deformation increases the efficiency of force transfer between the road surface and the tire, it reduces the rolling resistance and tread wearing of the tire (Figure 2). On the other hand, in case a vehicle moving at high speed brakes, due to the effective force transfer between the road surface and the tire in which the inventive cap ply reinforcement strip (1) is used, the vehicle can stop in shorter distance than normal. This is a factor which increases the safety of the vehicle (Figure 3).

The texturized weft yarns (2) absorb the adhesive material more easily due to their texturized structure, this increases the resistance and stability of cap ply reinforcement strip (1) in the tire under dynamic conditions. Another advantage provided with the inventive cap ply reinforcement strip (1) is that the noise originating from the tread deformation is reduced. Aside from chemical adhesion, mechanical interlocking between the cap ply reinforcement strip (1) and the tread formed by the weft elevations prevents the tread from separating from the cap ply reinforcement strip (1 ) at high speeds. This especially has great importance for radial aircraft tire. The width of the inventive cap ply reinforcement strip (1) varies between 5 to 30mm, preferably 8 to 15mm . The number of warp yarn (3) present in the 10mm width of the cap ply reinforcement strip (1 ) may vary between 3 to 20. The cord twist degrees of warp yarns (3) are between 100 to 800 twist/meter (tpm), preferably 250 to 350 tpm. The warp yarns (3) used in the inventive cap ply reinforcement strip (1 ) can be comprised of hybrid cords such as PET-nylon 6.6, aramide-nylon 6.6 or aramide- PET as well as it can be comprised of nylon 6.6, PET (polyethylene terephthalate), aramide cords. The cords used in warp yams (3) can comprise 2 to 7 nylon 6.6, PET or monofilaments of both the diameters of which are 0.1 to 1 mm.

The texturized weft yarns (2) are manufactured from at least one material selected from the group comprising nylon 6.6, nylon 4.6, nylon 6, PET (polyethylene terephthalate), PEN (polyethylene naphthalate) or rayon.

The linear densities of the texturized weft yams (2) can vary between 1400 to 6000 dtex, preferably 1400 to 3000 dtex. The texturized weft yams (2) used as weft can be twisted or non-twisted. The number of texturized weft yarns (2) in a 10cm long strip (1) can be 5 to 50, preferably 10 to 20.

The amount of the adhesive dip in the cap ply reinforcement strip is between 5% to 80%, preferably 8% to 40 or more preferably 10% to 25%.