Mechanical knowledge base: "rubber machinery"

Rubber machinery is a machine used to manufacture various rubber products such as tires, including general rubber machinery, tire machinery, and other rubber product machinery.

General rubber machinery

General rubber machinery is a machine for preparing rubber or semi-finished products, including raw material processing machinery, rubber refining machines, extruders, calenders, curtain canvas pretreatment devices and cutting machines.

Blender

Mixers are divided into two types, open and closed.

Open rubber mixing machine

It is mainly used for rubber hot-pressing, tablet pressing, gel breaking, plastic smelting and mixing. It consists of rollers, roller bearings, roller distance adjustment devices, emergency brakes, frames, stands, transmissions, and heating and cooling systems. The operating principle of the open-type rubber mixing machine is that the raw rubber or rubber material is pulled into the nip between two rollers rotating at different speeds with each other, and the plasticity is increased by the strong shearing and squeezing action. This double-roller open-type rubber mixer was put into production in 1826. Its structure is relatively simple and modern is still widely used.

Closed mixing machine

It is mainly used for rubber plastics mixing and mixing. It has one more mixing chamber than the open one (Figure 1). After the raw rubber and compounding agent are loaded into the smelting chamber from the hopper, the material door is closed and the top spigot of the ramming device is pressed down. The two rotors in the smelting chamber rotate at different or same speeds. The charged rubber material is constantly stirred, folded and strongly kneaded between the rotors, between the rotor and the mixing chamber, and generates oxidation-broken chains, increasing the degree of plasticity. At the same time, the rubber material is dispersed and evenly mixed due to the shearing effect, so as to achieve the purpose of compounding. Since the invention of the elliptical rotor closed-type rubber mixer in 1916, the closed-type rubber mixer has developed rapidly in the rubber industry. Later, other types of closed-type rubber mixers appeared. The rubber mixing cycle of the modern closed mixer is 2.5 to 3 minutes, and the maximum capacity of the mixing chamber is 650 liters.

Extruder

Used for extruding treads, inner tubes, hoses and all kinds of rubber strips. Also used to cover cables and wire products. Screw extruders are common. Its working principle is that the rubber material is stirred, mixed, plasticized and pressed in the barrel by means of the rotation of the extrusion screw, then moved toward the head, and finally a certain shape of product is extruded from the mouth shape. According to the needs of the product, multiple machines can be used to carry out compound extrusion of various rubber compounds. Screw extruder is divided into hot feed and cold feed. Hot feed extruders are usually fed into strips that have been preheated by an open mixer. The compound fed by the cold-feed extruder is not subjected to thermal refining, eliminating the need for thermal refining equipment.

Calender

It is mainly used for the application of glue or squeegee for curtain canvas, the lamination of rubber, the press-fitting and embossing. The main working part of the calender is a roller, and the number of rollers is usually 3 or more. When the rubber material with certain temperature and plasticity is fed into the gap of the rotating roller, it is strongly pressed and extended under the friction force to form the desired product. The first calender was made and used in production in 1857 and has since been continuously improved. Especially since the 1950s, the development of the plastics industry has strongly promoted the improvement of high-precision, high-speed calenders. In order to obtain a uniform thickness of the rolled product, the new calender generally has a roller deflection compensation device. The thickness of the rolled semi-finished products is measured with special equipment. Some calenders are also equipped with a computer-controlled automatic thickness adjustment system.

Tire machinery

Such machines include tire building machines, tire bead ring machines, tire shaping vulcanizers, capsule vulcanizers, pad vulcanizers, inner tube jointers and inner tube vulcanizers, as well as force tire machinery, tire reconditioning machines and reclaimed rubber production machines. More than 60% of the world's rubber is used to make tires, so tire machinery plays an important role in rubber machinery. Figure 2 is a tire production process.

Tyre forming machine

A green tire used to laminate various components such as rubberized curtains, bead rings, and treads into tires. Divided into two categories according to the use of ordinary tire forming machine and radial tire forming machine. Tire cords of common tire casing cords are inclined at an angle. During molding, the fabric drums are put on the forming drums first, and then the wire loops are laid on both sides, and the buffer layer and the tread rubber are covered in the middle to form the tires. The billet becomes a tube. The main difference between radial tires and ordinary tires in terms of structure is that the buffer layer cords are 90° to 75° (nearly orthogonal) to the carcass axis, so the diameter size of the buffer layer after forming cannot be changed greatly, so the carcass is made of Afterwards, it needs to expand to a shape that is approximately fixed, and then attaches a buffer layer. Therefore, the structure of the radial tire building machine is also different from the ordinary tire building machine.

The complete process of radial tire molding by a molding machine is called one-shot molding. The carcass is made using a modified ordinary tire building machine and then formed on a radial tire building machine called the two-stage forming method.

Tyre shaping vulcanizer

It is used for the vulcanization of tires for pneumatic tires such as automobiles, construction vehicles, tractors and airplanes. This machine appeared in the 1940s. In the shaping vulcanizing machine, the operations of loading tires, shaping, vulcanization, unloading of tires and post-aeration cooling can be completed. The temperature, pressure and steam chamber temperature of the superheated water in the capsule can all be measured, recorded and controlled, and the whole production process can be automated. get on. Many types of tire curing presses are AFV type, BOM type, and AUBO type (China is referred to as A type, B type, and AB type, respectively). Their main difference is that capsules and their handling mechanisms are different.

The AFV type tire shaping vulcanizer is characterized in that there is no complicated central mechanism in the lower part of the lower mold, and only one capsular tube is provided. In the upper part of the upper mold, a pneumatic pushing mechanism is installed. At the end of the vulcanization, the capsule is pushed into the capsule by the pusher mechanism, and the capsule is pushed out by the steam pressure introduced into the capsule and extends into the inner cavity of the blank.

The BOM type tire curing pressurization capsule is fixed by two upper and lower chucks, and the telescopic and integral lifting of the capsule is achieved under the drive of the central mechanism water tank. When loading and unloading the tire, the capsule is straightened, and its inner cavity is vacuumed at the same time, standing upright on the lower mold.

The AUBO type tire shaping vulcanizer is characterized in that the upper and lower openings of the capsule are fixed by a clamping ring and can be retracted into the capsule barrel. When the tire is mounted, the capsular cylinder rises, and the bead under the tire blank comes into contact with the steel ring on the capsular tube. Then, the upper chuck is lifted, and under the effect of the fixed steam pressure, the capsule is unfolded in the green tire, and then the capsule is lowered and the mold is vulcanized. When the end of vulcanization is unloaded, the capsule rises, and the capsule is drawn from the upper chuck into the capsule and the lower chuck is fixed.

Radial tire vulcanizing die

The development of radial tires puts forward higher requirements on the precision of tire shaping vulcanizers. Newly developed curing presses are NRMPost type and RIB type (Rolling in Bladder).

The active mode is produced and developed to meet the special structure of radial tires and their requirements for vulcanization processes. In the moving mode, the tread pattern setting ring is composed of several moving sector blocks. These segments can be opened when loaded and can be moved when vulcanized. This sector block adopts the mode of clamping the raw tire tread from the radial direction, which effectively eliminates the deformation and displacement of the green tire belt layer, and is favorable for ensuring the quality of the radial tire after vulcanization.

Tire repair machinery

Used to repair worn or damaged tires. The type of tire reconditioning machine depends on the renovation process. Tire repair technology can be divided into traditional methods, pre-cured tread method, pressure tread method and winding tread method. 1 The machines used in the traditional methods include the tire-removing machine, the grinding machine, the laminating machine and the vulcanizing machine. 2 The precured tread method uses an adhesive to adhere the pre-vulcanized tread to the carcass of the worn tire, and then puts on the envelope made of rubber and puts it into the vulcanization tank under low temperature and pressure. Carry out vulcanization. (3) The machinery used for the pressure tread method is mainly a pressure tread extrusion machine that directly presses the tread on the carcass. 4 The method of wrapping the tread is to use a small adhesive tape winding method to adhere to the carcass to form a tread strip.