Abrasion resistance is a critical mechanical property of vulcanized rubber, reflecting its ability to withstand wear and tear from friction forces. It is closely linked to the service life of rubber products.
Forms of Abrasion Resistance
1) Wear Abrasion:
- Description: Caused by sharp, rough objects constantly cutting and rubbing against the rubber surface during use. This action leads to the detachment of tiny particles from the contact points.
- Influencing Factors: Friction pressure, tensile strength, and rebound resilience.
2) Fatigue Abrasion:
- Description: Occurs when rubber products are subjected to continuous cyclic compressions, shear, and tensile deformations, leading to surface fatigue and the gradual formation of cracks.
- Influencing Factors: Elastic modulus, pressure, and tensile strength of the rubber.
3) Rolling Abrasion:
- Description: When rubber contacts a smooth surface, friction causes the uneven parts of the rubber to deform and tear off in rolls.
- Influencing Factors: Surface smoothness and the nature of the contacting materials.
Enhancing Abrasion Resistance
To improve the abrasion resistance of rubber products, several strategies can be employed:
1) Choosing the Right Rubber Type
- Opt for rubber types known for high abrasion resistance.
2) Vulcanization System:
- Use CZ as a vulcanization accelerator to enhance resistance.
3) Carbon Black:
- Select small particle size carbon black and improve its dispersion within the rubber to enhance durability.
4) Softener Usage:
- Minimize the use of softeners to prevent compromising abrasion resistance.
5) Antioxidants:
- Use fatigue-resistant antioxidants to improve the overall durability of the rubber compound.
6) Additional Fillers:
- Incorporate additives such as silane coupling agents or molybdenum disulfide to improve wear resistance.
The abrasion resistance of rubber products directly impacts their service life. During the design phase, selecting the appropriate rubber type and material grade is crucial to meet the specific abrasion performance requirements of the application. This ensures that the product will have a longer service life and perform effectively in its intended use.
Comparison of Abrasion Resistance in Different Types of Rubber
| Type of Rubber | Abrasion Resistance | Description | Applications |
|---|---|---|---|
| Natural Rubber (NR) | High | Excellent tensile strength and good abrasion resistance. | Tires, conveyor belts |
| Styrene-Butadiene Rubber (SBR) | Moderate to High | Good abrasion resistance, durable, cost-effective. | Automotive tires, footwear |
| Nitrile Rubber (NBR) | Moderate | Good resistance to oils and fuels, moderate abrasion resistance. | Seals, gaskets |
| Chloroprene Rubber (CR) | Moderate | Also known as neoprene, balanced properties with moderate abrasion resistance. | Hoses, gaskets |
| Ethylene Propylene Diene Monomer (EPDM) | Low to Moderate | Excellent resistance to weathering and ozone, moderate abrasion resistance. | Weather seals, automotive parts |
| Silicone Rubber | Low | Excels in extreme temperature conditions but low abrasion resistance. | Medical devices, sealants |
| Polyurethane Rubber (PU) | Very High | Exceptional abrasion resistance, ideal for high-wear applications. | Wheels, rollers, industrial components |
| Fluoroelastomer (FKM) | Moderate | High chemical and heat resistance, moderate abrasion resistance. | High-performance seals, gaskets in harsh environments |
Comparison of Wear Resistance: PTFE vs. Rubber
Polytetrafluoroethylene (PTFE) and rubber are two commonly used wear-resistant materials, each possessing unique properties and applications. Here is the analysis of the wear resistance of these two materials.
1. Polytetrafluoroethylene (PTFE)
- Properties:
- Chemical Stability: PTFE, exhibits exceptional chemical stability and non-stick properties. It remains stable under extreme temperatures (ranging from -80°C to 260°C) and is nearly impervious to chemical attack.
- Low Friction Coefficient: With a friction coefficient ranging from 0.05 to 0.1, PTFE excels in sliding and rotating components. However, its wear resistance is relatively poor due to its low hardness, making it susceptible to scratches and wear.
2. Rubber
- Properties:
- Elasticity and Toughness: Rubber is an elastomer with excellent elasticity and toughness. It demonstrates superior wear resistance at room temperature, especially in dry and clean environments.
- Molecular Structure: The wear resistance of rubber is primarily attributed to its long-chain molecular structure, which can rearrange under stress to absorb and dissipate energy. While rubber typically outperforms PTFE in wear resistance, its performance can degrade under extreme temperatures and chemical exposure.
Wear Resistance Comparison Chart
| Property | PTFE | Rubber |
|---|---|---|
| Chemical Stability | Excellent, resistant to nearly all chemicals | Good, but can degrade with certain chemicals |
| Temperature Range | -80°C to 260°C | Varies by type, typically -40°C to 120°C |
| Friction Coefficient | 0.05 – 0.1 | Higher than PTFE, varies with type |
| Hardness | Low, making it more susceptible to wear | Higher, provides better wear resistance |
| Elasticity | Low | High, allows absorption and dissipation of energy |
| Wear Resistance | Moderate, better in low-load applications | High, especially in dry and clean environments |
| Applications | Chemical processing, pharmaceuticals, food processing | Tires, conveyor belts, seals |
When choosing rubber seals for various applications, especially in wear-resistant, please contact OBT for a better solution.
