In the high-temperature hot-pressing environment of rope and belt hot pressing machines, the material selection for sealing components directly impacts the equipment's stable operation and replacement cycle. High temperatures accelerate material aging and degradation. Furthermore, pressure fluctuations, mechanical friction, and potential contact with oils, contaminants, and additives during the hot-pressing process can continuously impact sealing performance. If the material cannot withstand these complex conditions, it can harden, crack, deform, or wear, leading to seal failure. This not only affects hot-pressing accuracy but also requires frequent downtime and replacement, increasing production costs. Therefore, selecting sealing materials that can withstand high temperatures, resist aging, and possess excellent mechanical properties is crucial for extending replacement cycles.
High-temperature resistance is a primary consideration for sealing component materials. During hot-pressing, the hot-pressing zone of the equipment typically remains at elevated temperatures. Sealing materials must maintain stable physical properties despite prolonged exposure to high temperatures, preventing softening, melting, or decomposition due to excessive temperatures. The stability of a material's molecular structure determines its high-temperature resistance. Materials with strong inter-chain bonding and excellent thermal oxidation resistance can maintain their original elasticity and strength in high-temperature environments, preventing the degradation of sealing performance caused by thermal aging. The material also needs to have good thermal conductivity or insulation properties to prevent excessive heat transfer to non-hot-pressing areas, indirectly protecting the sealing components themselves from continuous erosion caused by extreme temperatures.
Resistance to mechanical wear and pressure shock is also crucial. During operation, the sealing components of rope and belt hot pressing machines must fit tightly against other equipment components under pressure, potentially accompanied by slight relative movement or vibration. This requires the material to possess sufficient hardness, toughness, and wear resistance. Excessively hard materials are prone to brittle fracture under repeated pressure, while overly soft materials may deform due to excessive compression, increasing the sealing gap. The ideal sealing material should possess an appropriate balance of elasticity and rigidity to ensure an effective seal under pressure while also resisting wear caused by long-term friction, minimizing the need for replacement due to mechanical damage. Furthermore, the material's resistance to permanent compression set is crucial, ensuring it maintains its original shape and sealing effectiveness even after prolonged pressure.
Resistance to chemical agents is another key factor in extending the life of sealing components. During the hot pressing process, the cord may come into contact with surface treatment agents, lubricants, or processing aids. Chemical reactions between these substances and the sealing material can cause swelling, hardening, or performance degradation. Therefore, the sealing material must be chemically inert, resistant to common chemical attack, and maintain structural stability. Especially when working with cords that have undergone special coatings or impregnation, the chemical resistance of the sealing material directly determines its ability to maintain its sealing function over the long term, preventing premature failure due to chemical corrosion.
The material's elastic recovery properties significantly impact the durability of the seal. Sealing components achieve their sealing function by elastically deforming to fill gaps in equipment. However, under prolonged exposure to high temperatures and pressure, the material's elasticity can gradually diminish, leading to permanent deformation. Selecting a material with excellent elastic recovery properties ensures that the seal maintains sufficient contact pressure during repeated hot pressing cycles, maintaining an effective seal. This elasticity is not only maintained at room temperature, but also in elevated temperatures to prevent loss of elasticity and seal failure due to elevated temperatures, thereby reducing the need for replacement due to seal defects.
The material's aging and fatigue resistance determine the long-term stability of the seal. High temperatures accelerate the oxidative aging process of materials, leading to a gradual decline in material performance. Repeated thermal expansion and contraction, as well as pressure cycling, can cause fatigue damage. Materials with excellent anti-aging additives or inherently stable molecular structures can delay oxidation reactions and mitigate performance degradation caused by aging. Furthermore, the stronger the material's fatigue resistance, the less likely it is to crack or break under long-term cyclical stress, thereby extending the life of sealing components and reducing replacement frequency.
Sealing materials suitable for high-temperature hot pressing environments must strike a balance between high-temperature resistance, wear resistance, chemical corrosion resistance, elastic recovery, and aging resistance. Such materials maintain stable performance under complex operating conditions, effectively withstanding the combined effects of high temperature, pressure, friction, and chemical attack, reducing the need for replacement due to material failure. Choosing the right sealing material not only extends replacement cycles and reduces equipment maintenance costs, but also ensures the continuous and stable operation of rope and belt hot pressing machines, improving overall production efficiency.
