RUBBER RECIPE FORMULATION
Rubber is a product obtained by mixing elastomers with fillers and other ingredients followed by vulcanization. Vulcanization is used to impart to the rubber mechanical strength, high elasticity and resistance to solvents. The properties of rubber are determined by the properties and the relative amount of the main components (elastomer, sulfur, fillers, antioxidants, etc.), the mode of production of rubber compounds, the degree and method of their vulcanization.
So, the elasticity of rubber depends on the amount of sulfur, so the rubber is divided into soft (2-8% sulfur), medium hardness (12-20% sulfur) and increased hardness (25-60% sulfur). Addition of carbon black increases the strength of rubber and the addition of plasticizers increase its frost resistance. Rubber is characterized by elastic (highly elastic) deformation. The limits of practically reversible deformation of rubber are 20-30 times greater than that of steel. Its ability to elastic deformations depends on temperature. A high volumetric resilience resembles a liquid.
The experience of creating recipes for rubber compounds, accumulated over more than a quarter-century of the company’s development, shows that this process can be conditionally divided into two stages:
1) development of rubber recipe formulation, i.e. determination of the minimum number of ingredients and their approximate content, as well as the choice of a rational technology for the production of rubber compounds;
2) optimization of the basic recipe in order to find the best balance between technical, technological properties and production costs.
All the ingredients of rubber compounds, except for elastomer, are divided into the following groups of curing agents, vulcanization accelerators, accelerator activators, fillers (active, or amplifiers, and inactive), softeners, antioxidants, colorants.
The production of rubber compounds involves the plasticizing operations of rubber by rolling with the sequential introduction of the following ingredients: 1 – antioxidants 2 – vulcanizers 3 – fillers and softeners. The vulcanization accelerator is added last to the compound.