Materials for Dredging Hoses
- Raw rubber and compounding agent
The raw rubber used for dredging hoses is generally based on natural rubber, with synthetic rubber with better wear resistance such as BR and SBR.
In the compounding agent, materials with small particle size, large surface area, and good reinforcing performance are used more in the inner rubber layer compound to improve the wear resistance, such as N220 series carbon black with small particle size instead of N330 series Carbon black is used in the rubber compound of the inner rubber layer. Some new dispersants, tackifying resins, accelerators, and antioxidants have been used in the manufacture of dredging hoses, which can improve the physical and mechanical properties and environmental performance of the rubber.
- Metal materials
The metal materials used in the dredging hose include flanges and connectors, binding steel wires for fixing the cord, steel rings or metal spirals in the reinforcement layer of the suction hose, and wear-resistant rings in the wear-resistant hose with embedded rings, etc.
- Reinforcing layer cord material
In the 1980s and early 1990s, the reinforcement layer material of dredging hoses was mostly steel cord. Because the fatigue performance of steel wire is not good, and it is not resistant to seawater corrosion, which affects the working life, the steel cord is gradually withdrawn in the late 1990s and replaced by nylon cord. Nylon cord has high strength and good affinity with rubber, but its elongation is high (usually 23%), and the deformation of the hose in the working state is large, which will accelerate the wear of the inner rubber layer. Nowadays, large-diameter polyester industrial filaments are mostly used as cord fabrics. Polyester cord has good elasticity, low elongation (generally 15%), and the deformation of the hose under pressure is small. For cords with a wire diameter of 1.4mm, the breaking force of a single strand can reach more than 90kg. In recent years, there have been certain achievements in the research of new materials for cord fabrics.
- Other materials
In recent years, other materials have also been used in the manufacture of dredging hoses. For example, ceramic materials. Ceramic material is an emerging composite material, the main component is Al2O3, which is sintered at high temperatures above 1700 °C. Using this material for dredging hoses can significantly improve the wear resistance of the product, reduce working resistance and reduce working energy consumption.
