Tensile strength: also known as tensile strength. It refers to the force required per unit area for rubber to elongate to a certain length, that is, to elongate to 100%, 200%, 300%, 500%. Expressed in N/cm2. This is an important mechanical indicator for measuring the strength and toughness of rubber. The larger its value, the better the rubber’s resilience, indicating that this type of rubber is less prone to elastic deformation.
Tear resistance: If rubber products have cracks during use, they will tear harder and eventually become scrapped. So tear resistance is also an important mechanical performance indicator for rubber products. Tear resistance is usually measured by the tear resistance value, which refers to the force required per unit thickness (cm) of rubber to tear at the incision until it breaks, measured in N/cm. Of course, the larger the value, the better.
Adhesion and adhesion strength: The force required to separate the two bonding surfaces of rubber products (such as glue and cloth or cloth and cloth) is called adhesion. The size of adhesion is usually measured by adhesion strength, which is expressed as the external force required per unit area when the two bonding surfaces of the sample are separated. The calculation unit is N/cm or N/2.5cm. Adhesive strength is an important mechanical performance indicator in rubber products made of cotton or other fiber fabrics as skeleton materials, and of course, the larger the value, the better.
Wear loss: also known as a certain wear reduction, is the main quality indicator for measuring the wear resistance of rubber materials, and there are many methods for measuring and expressing it. At present, China mostly adopts the Akron abrasion test method, which involves the friction between a rubber wheel and a standard hardness grinding wheel (Shore 780) under a certain inclination angle (150) and a certain load (2.72kg) to determine the wear amount of rubber within a certain stroke (1.61km), expressed in cm3/1.61km. The smaller this value, the better the wear resistance of the rubber.
Brittle temperature and glass transition temperature: These are quality indicators for determining the cold resistance of rubber. Rubber will begin to harden below zero degrees Celsius when ingested, greatly reducing its elasticity; As the temperature continues to decrease, it gradually hardens to the point where its elasticity is completely lost, just like glass, which is brittle and hard, and can shatter upon impact. This temperature is called the glass transition temperature, which is the lowest operating temperature for rubber. In industry, the glass transition temperature is generally not measured (due to long time), but the brittle temperature is measured. The temperature at which rubber begins to fracture after being frozen at low temperature for a period of time and subjected to a certain external force is called the brittle temperature. The brittle temperature is usually higher than the glass transition temperature, and the lower the brittle temperature, the better the cold resistance of this rubber.
Cracking temperature: After the rubber is heated to a certain temperature, the colloid will crack, and this temperature is called the cracking temperature. This is a performance indicator for measuring the heat resistance of rubber. The higher the cracking temperature, the better the heat resistance of this rubber. The actual operating temperature range of general rubber is between the brittle temperature and the cracking temperature.
Anti swelling property: Some rubber products often come into contact with substances such as acid, alkali, oil, etc. during use, which cause the rubber products to expand, the surface to become sticky, and ultimately the products are scrapped. The performance of rubber products in resisting the effects of acid, alkali, oil, etc. is called anti swelling. There are two methods for measuring the swelling resistance of rubber: one is to immerse the rubber sample into a liquid medium such as acid, alkali, oil, etc., and after a certain temperature and time, measure its weight (or volume) expansion rate; The smaller its value, the better the rubber’s resistance to swelling. Another way is to express it by the ratio of the tensile strength after immersion to the tensile strength before immersion, which is called acid (alkali) resistance or oil resistance coefficient; The larger this coefficient, the better the rubber’s resistance to swelling.
Aging coefficient: The aging coefficient is a performance indicator that measures the aging resistance of rubber. It is expressed as the ratio of the physical and mechanical properties (tensile strength or the product of tensile strength and elongation) of rubber after aging at a certain temperature and for a certain period of time. A high aging coefficient indicates good aging resistance of this rubber.
Post time: Dec-06-2024
