Full definition
Rubber lining vulcanization is a specialized process used to create a durable and effective bond between rubber sheets and metal surfaces in various industrial applications. This technique is particularly crucial in industries such as mining, where equipment is subjected to harsh conditions and wear. The process begins with surface preparation, where the metal is grit-blasted to achieve a profile according to SSPC-SP10 or ISO Sa 2.5 standards, with a roughness of 50-100 μm. This ensures that the surface is clean and conducive for adhesive bonding. Following the grit-blasting, a primer such as Chemlok 205 is applied within four hours to enhance adhesion. After the primer has dried, a cover coat adhesive like Chemlok 220 is applied, which further guarantees a strong bond when the uncured rubber sheet is placed on top.
The rubber sheets used in this process can be pre-calendered to various thicknesses ranging from 3 mm to 50 mm, allowing for flexibility depending on the application. The application is performed using a hand roller to ensure full contact with the adhesive and to eliminate any trapped air pockets that could compromise the bond. The vulcanization process itself can be executed through various methods, such as autoclaving, press curing, or using hot-air/infrared blankets, with autoclaving being the preferred method for its ability to produce the strongest and most uniform bonds. Typical vulcanization conditions involve steam at temperatures between 145-155°C and pressures of 3-5 bar for 30-90 minutes.
Quality assurance is a vital part of rubber lining vulcanization. Spark testing at 15 kV/mm is performed to detect any pinholes in the lining, while adhesion testing is conducted according to ASTM D429 standards to ensure the bond strength meets specifications. Additionally, hardness verification is crucial to assess the quality of the vulcanized rubber. Applications of this technology include linings for chemical reactors, flue gas desulfurization (FGD) vessels, mineral processing tanks, cyclones, and mill shells, all of which benefit from enhanced durability and resistance to wear and corrosion.