The temperature pulverization method is mainly divided into two kinds of processes, one is a low temperature pulverization process, and the other is a pulverization process in which a low temperature and a normal temperature coexist.

 

 

Low temperature pulverization process

 

 

The low-temperature pulverization is freezing with liquid nitrogen, and the waste rubber product is cooled to below the glass transition temperature, and then pulverized by a hammer mill or a roller mill. Low temperature pulverization is divided into the following two methods.

 

(l) Direct freezing cryogenic pulverization method. The production process of the pulverization method is: cutting the bead portion of the tire on the tire dissection machine, and dividing the tread into 2 to 3 small pieces, placing them in a freezing (liquid nitrogen) device, and then using a hammer or a roller. The barrel mill was pulverized to obtain a rubber powder.

 

(2) Low-temperature pulverization method of coarsely pulverizing and then finely pulverizing under freezing conditions. The production process of this pulverization method is: after the waste tire is cut according to the method (l),

 

It is placed in a freezer and coarsely crushed in a hammer or roller mill. After coarse crushing, it is again frozen and then finely crushed to obtain a rubber powder. This producer

 

The method requires two liquid nitrogen freezing, so the production cost is high. However, when the steel radial tire is treated by the method, the steel wire is easily separated from the rubber, and the power consumption can be reduced accordingly.

 

The low temperature pulverization process has the following advantages :

 

(l) It is most suitable for crushing substances that are not easily pulverized at normal temperature, such as rubber, thermoplastics, etc.

 

(2) The built-in classifier can obtain obvious particle size distribution powder materials.

 

(3) It can obtain finer and more fluid powder than normal temperature pulverization, and the powder after pulverization has good moldability.

 

(4) Avoid dust explosion, odor pollution and noise

 

(5) The power required for crushing is very low, which can increase the output of the crusher.

 

(6) Crushing heat sensitive substances will not be deteriorated by oxidation and heat

 

(7) Using the difference in low-temperature brittleness of various materials, it is possible to selectively pulverize complex materials such as rubber, metal and fiber.

 

As a high-elastic material at room temperature, the polymer material rubber is made into a brittle substance by lowering the temperature, and is pulverized in a pulverizer that maintains a low temperature, thereby obtaining an ideal pulverization effect, which cannot be replaced by other pulverization methods. The prepared rubber powder has a small particle size and a regular surface