Ribber Belt Vulcanization Process
Ribber Belt vulcanization process
The Ribber Belt band is the main component of the pulling and carrying material, and the cotton canvas, polyester canvas or nylon canvas is used according to the tension.
Other parts of the conveyor designed to meet a variety of strong requirements, Ribber Belt connection According to different working conditions can be used mechanical joints, cold glue joints, curing joints, the choice of flexible. To understand the vulcanization process of Ribber Belt is the need to master the nature of vulcanization and the factors affecting the vulcanization, curing conditions to determine and implementation methods, flat vulcanizing machine operating methods, structure, which is a certain temperature, time and pressure, Of the linear macromolecules for cross-linking, the formation of three-dimensional network structure of the process.
The vulcanization reduces the plasticity of the Ribber Belt, increases the elasticity, increases the ability to resist external deformation, and improves other physical and chemical properties. The Ribber Belt becomes the engineering material with the use value. The vulcanization is the last step in the processing of the Ribber Belt product. Of the vulcanized Ribber Belt on the performance of a great impact, therefore, should strictly control the curing conditions, vulcanization machine two hot plate pressure surface should be parallel to each other.
Ribber Belt hot plate with steam heating or electric heating, the plate in the entire curing process, the mold cavity area imposed on the pressure of not less than three MPa, regardless of the type of hot plate, the entire mold area on the temperature distribution Should be uniform, the same hot plate between the points and the point between the center and the maximum temperature difference between no more than once, the adjacent two plates between the corresponding position of the temperature difference is not more than once, the hot plate at the center of the maximum temperature difference does not exceed Zero five degrees, the commonly used technical specifications for the maximum closing pressure of 200 tons, the maximum stroke of the plunger is 200 mm, the flat area of five hundred by 500 mm, the working layer is a layer, the total heating power of 27 kilowatts The
At present, the method of determining the degree of vulcanization of Ribber Belt compound can be divided into three categories: physical-chemical method, physical and mechanical property method and test instrument method. These methods measure the degree of vulcanization of Ribber Belt from different angles;
Physical-chemical method: Determination of free sulfur by vulcanization of different curing time in the determination of the amount of sulfur can be made at different times the amount of free sulfur and the corresponding time curve, the minimum amount of free sulfur corresponding to the time and mouth For the theory of vulcanization time, but the law does not adapt to non-sulfur vulcanization system Ribber Belt;
Sweep method: Determine the equilibrium swell rate of the different vulcanization time compound, the minimum value of the equilibrium swelling rate corresponding to the curing time is positive curing time;
Physical and mechanical properties of the law: the physical and mechanical properties of the changes and the degree of cross-linking are closely related to the low elongation of the tensile stress and cross-linked density is proportional to the relationship between the hardness and the relationship between the tensile strength, tear strength and other mechanical Performance of the peak relationship, the use of products often depends on the performance, so in the early absence of curing equipment, people use physical and mechanical properties of Ribber Belt compounds with the degree of curing, so the law can be considered a continuation of the early measurement method, although for Different products may require different key physical and mechanical properties, so the optimal corresponding physical and mechanical properties of the corresponding time and the positive curing time, and as follows:
Tensile Strength Method: The maximum value of the tensile strength or the time corresponding to the starting point of the flat area of the curve is used as the positive vulcanization time;
Compression permanent deformation method: Determine the compression set value of the Ribber Belt compound for different curing time, the time point of the turning point or inflection point of the Ribber Belt tape compression set time curve is the corresponding time of the vulcanization point;
Ribber Belt vulcanization conditions of products generally refers to the vulcanization of the temperature, pressure, time, they constitute the main factors of curing conditions, also known as "three elements of sulfur";
Vulcanization is a complex chemical reaction process between Ribber Belt and crosslinking system additives. The temperature is a necessary condition for crosslinking reaction. The vulcanization temperature is high, the vulcanization speed is high, the production efficiency is high, and the vulcanization speed is slow and the production efficiency is low. Factors affecting the vulcanization temperature;
The main factors are the type of Ribber Belt and vulcanization system, the impact of Ribber Belt varieties mainly reflect two aspects: First, the sensitivity of the temperature on the reaction, the second is its tolerance to temperature, generally natural Ribber Belt-based formula vulcanization temperature Relatively low, too high Ribber Belt material easy to return to the original, styrene butadiene Ribber Belt, nitrile Ribber Belt vulcanization temperature can be higher.