KR20050002971A - Tire bladder - Google Patents

Abstract

PURPOSE: A bladder for a tire molding machine is provided to reinforce mechanical properties by forming a reinforcing fiber layer coated with silicon rubber on the upper part of a glass fiber and to expand the life span of the bladder by applying release property. CONSTITUTION: A bladder for a tire molding machine is used for manufacturing a green tier by assembling tire half-finished products. The bladder is expanded by pneumatic pressure applied to the inside. And then the bladder pushes rubber half-finished sheets to adhere the sheet to each other and has a reinforcing fiber layer at a turn-up portion contacting with the rubber. The reinforcing fiber layer is formed by layering a glass fiber(11) and silicon rubber(12) in order from a surface contacting with the bladder rubber. The thickness of the reinforcing fiber layer is within 0.1¯1mm.

Description

Bladder for tire molding machine {Tire bladder}

The present invention relates to a bladder for a tire molding machine, and more particularly, to a bladder for a tire molding machine which is used to provide a tire green case by combining a tire semi-finished rubber sheet.

Looking at the tire green case manufacturing process, the inner liner is pierced on the forming drum and carcass is attached to the upper surface of the inner liner. After inserting the ring-shaped bead part on both sides of the carcass, it is inflated by applying pneumatic pressure to the inside to inflate the carcass and the bead part on both ends, and the bladder is used during this process. .

At this time, the bladder part that is expanded and turned up is adhered to the semi-finished rubber and has high deformation rate, which causes the wear and abrasion to occur earlier than other parts, thereby reducing the service life. As a result of the adhesion phenomenon, the liquid release agent has to be applied and dried at regular intervals, thereby causing a decrease in the quality and productivity of the tire.

In order to solve this problem, a method of reinforcing the portion of the bladder contacted with rubber by expanding the rubber semi-finished sheet to be bonded to each other after being inflated by the air pressure applied therein has been devised. Reinforcement by attaching a separate rubber sheet, a method of padding an organic fabric cord consisting of nylon or polyester, which is made of one-way rubber-topping, or an elastic fabric fiber cord made of a mixture of nylon and polyurethane There have been methods.

The cross section of the bladder reinforced by the addition of the other rubber sheet is shown in FIG. 1, the reinforcing rubber sheet 1 was attached to the portion of the bladder for pushing the semi-finished rubber.

Of course, when the fabric cord is coated on the bladder rubber, the adhesiveness and reinforcement are significantly improved compared to the conventional ones, thereby increasing the lifespan. However, in the early stages of use, the same adhesion phenomenon occurred as the rubber began to be exposed between the cord papers when they were aged by repeated use, and the cord papers were detached or destroyed, thereby reaching the end of their service life.

On the other hand, there has been a technique of coating a solid silicone rubber on the bladder rubber surface to be turned up. This technology provided bladder with superior performance over existing methods. However, even when coating directly on the rubber surface, the same problem occurs when the silicone rubber is worn or detached by mechanical friction or when the adhesion is weak.

Accordingly, in order to improve the performance of the bladder, it is necessary to simultaneously provide reinforcement and releasability to the parts of the bladder that are in contact with the rubber after being pushed to bond the rubber semi-finished sheets to each other after being expanded by the air pressure applied therein.

Accordingly, the inventors of the present invention are exploring other ways to simultaneously impart reinforcement and releasability by reinforcing the portion of the bladder that is inflated by applying air pressure to the rubber directly, and the solid silicone rubber is coated on one side thereof. As a result of reinforcing the glass fiber of high strength, it was found that the silicone rubber is excellent in releasability by imparting releasability while acting to reinforce mechanical properties such as wear resistance to the bladder rubber, thereby completing the present invention.

Accordingly, it is an object of the present invention to provide a bladder for a tire molding machine, in which a turn-up portion is reinforced to satisfy reinforcement and releasability.

Bladder for tire molding machine of the present invention for achieving the above object is used to manufacture a green tire by assembling the semi-finished product, and is pushed to bond the rubber semi-finished sheet to each other after inflated by the air pressure applied therein The reinforcing fiber layer has a reinforcing fiber layer at a turn-up part in contact with rubber, and the reinforcing fiber layer has a structure in which glass fibers and silicon rubber are sequentially laminated from a contact surface with the bladder rubber.

1 illustrates an example of adding a rubber sheet to a turn-up portion of a bladder according to a conventional method,

2 illustrates an example in which a reinforcing fiber layer having a structure in which glass fibers and silicon rubber are sequentially stacked on a turn-up portion of the bladder according to the present invention is illustrated.

* Explanation of the main symbols in the drawing

1-rubber sheet

11-glass fiber, 12-silicone rubber

The present invention will be described in more detail as follows.

The present invention relates to a bladder for a tire molding machine with a reinforcement of the turn-up site.

The bladder in which the turn-up part of the present invention is reinforced has a reinforcing fiber layer in which glass fibers 11 and silicon rubber 12 are laminated on the turn-up part, as shown in FIG.

Glass fiber is a high-strength fiber with excellent abrasion resistance and abrasion resistance.Adhesion between glass fiber and bladder rubber is applied by coating rubber cement on the surface of rubber and then silane treatment on the adhesive surface of the glass fiber with bladder rubber. It can be carried out by a method of curing.

At this time, the glass fiber is used by coating a solid silicone rubber with excellent releasability by the knife coating method. In this case, when the solid silicone rubber is commercially available for glass fiber coating, it exhibits good adhesion with glass fiber.

Specifically, the silicone rubber to be coated is a type that can be easily adhered to glass fibers, and it is preferable that the Shore A hardness is 30 or more, the tensile strength is 20 kgf / cm 2 or more, and the elongation is 100% after normal temperature curing or heat curing. As practical use, DSE 463 of Dongyang Silicon Co., Ltd. may be mentioned.

The glass fibers are arranged in only one direction, so that the rubber, which forms a matrix between the glass fibers, expands when expanded, and the glass fibers serve to reinforce mechanical properties such as wear resistance.

In addition, when the silicone rubber coated on the organic fiber is reinforced with the structure according to the present invention, even if the silicone rubber coated on the glass fiber surface is detached by mechanical friction due to the use of the bladder, the glass fiber is exposed and related problems occur. It can serve as a secondary suppression. Therefore, compared with the existing bladder, it is possible to provide much improved performance in terms of overall performance.

As described above, the silicone rubber coated glass fiber reinforcement layer has a thickness of about 0.1 to 1 mm, and is thin enough to not affect the overall profile of the bladder.

According to the present invention, a method of manufacturing a bladder reinforced with a turn-up part is applied, and rubber cement is applied to the turn-up part of the bladder rubber sheet manufactured according to a conventional method, and then one side is surface-treated with silane and the other side is Silver coated silicone rubber adheres to the silane-treated side of the glass fiber oriented in a single direction. Then, the bladder can be manufactured by performing vulcanization by adding the same to the vulcanizer in the same manner as in the usual method.

The reinforcing fiber layer structure of the present invention is not limited to the bladder substantially, even if the rubber parts that are similarly dynamic and cause similar problems require mechanical reinforcement and reinforcement of releasability through the glass fibers. Of course it can be. It will also be included if the release material is treated on the above mentioned textile cord surface for reinforcement purposes in addition to glass fibers.

As an example of this, it is also applicable to the reinforcement of the portion in contact with the green tire bead portion on the surface of the bead locking device for forming a tire as disclosed in the Republic of Korea Patent Publication No. 1999-024837. In this case, it could be confirmed that the bead contamination prevention effect and the life improvement effect due to the reinforcing fiber under the silicone rubber according to the use of the liquid release agent.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited by the Examples.

Example 1

Rubber cement was applied to the turn-up site of the bladder rubber sheet prepared according to a conventional method. Here, one side is surface-treated with silane and the other side is coated with silicone rubber (Dongyang Silicone Co., Ltd., DSE463, silicone rubber for glass fiber coating) to attach the silane-treated side of glass fiber oriented in a single direction. It was. Then, a bladder was prepared by vulcanization by adding to a vulcanizer in the same manner as usual. At this time, the total thickness of the glass fiber and the silicone rubber was 0.4 mm.

The bladder thus obtained was used for the test production of the 165 / 70R13S standard, a passenger car tire for PCR.

The average lifespan, replacement rate due to wear of the turn-up site, the OE maker U / F acceptance rate, and the time of use of the liquid release agent were measured, and the results are shown in Table 1 below.

Comparative Example 1

The tire production test was carried out in the same manner as in Example 1, except that the general bladder was not reinforced at all as a bladder. The results are shown in Table 1 below.

Comparative Example 2

The tire production test was carried out in the same manner as in Example 1, except that the bladder in which only the reinforcing fiber (polyester fabric cord) was reinforced on a conventional bladder rubber sheet was performed. The results are shown in Table 1 below.

Example 1 Comparative Example 1 Comparative Example 2 Average life expectancy (ten life expectancy, ten times) 11000 3700 5300 % Change due to wear of turn-up area 20 80 60 U / F Pass Rate (%) 98 93 95 When to Use Liquid Release Agent Very small amount Apply once per 10 tires After 2000 tires use

From the results of Table 1, the bladder reinforced according to Example 1 had an average lifespan of 11000 times each, 3700 times for Comparative Example 1, 5300 times for Comparative Example 2, and the OE maker U / F acceptance rate was It can be seen that the results show an increase of 5% and 3%, respectively, compared to Comparative Examples 1 and 2 on the same basis. This result is interpreted to be due to less tire deformation during deformation such as expansion due to the prevention of adhesion due to the use of silicone rubber.

In addition, in the case of the bladder of Example 1, the replacement loss is reduced due to the improved lifespan and the liquid release agent does not need to be applied, thereby reducing the time required to apply and dry the release agent, thereby improving tire productivity, reducing costs, and using semi-finished products when using the release agent. It shows that it is possible to obtain effects such as reduction of defects caused by infiltration.

As described in detail above, in the case of reinforcing the high-strength glass fiber having excellent abrasion resistance and abrasion resistance according to the present invention and introducing a reinforcing fiber layer coated with silicone rubber on top thereof, mechanical properties such as wear resistance are reinforced and silicone rubber The mold release bladder is extended to increase the life expectancy of the tire forming bladder and to reduce the replacement loss due to the improved service life, and the process of applying the liquid release agent can be omitted, thereby reducing the time required to apply and dry the release agent to reduce productivity. It can improve the cost, reduce the cost, and reduce the defects caused by the release of semi-finished products.

Claims (4)

It is used to manufacture green tires by assembling semi-finished tires, and it is used in bladder for tire molding machine which has a reinforcing fiber layer on turn-up part in contact with rubber after being inflated by the air pressure applied therein to adhere the rubber semi-finished sheets to each other. , The reinforcing fiber layer is a bladder for a tire molding machine, characterized in that it has a structure in which glass fibers and silicone rubber are sequentially laminated from the contact surface with the bladder rubber. The bladder according to claim 1, wherein the reinforcing fiber layer has a thickness of 0.1 to 1 mm. The bladder for tire molding machine according to claim 1, wherein the reinforcing fiber layer is one surface of glass fiber adhered to the bladder rubber. The bladder for a tire molding machine according to claim 1, wherein the silicone rubber has a Shore A hardness of 30 or more, a tensile strength of 20 kgf / cm 2 or more, and an elongation of 100% after room temperature curing or heat curing.