Rubber technology

(6) Tensile strength of tensile strength
When the working length of the specimen in the test is partially stretched to a given elongation, the force per unit area calculated from the original area is the tensile stress at the elongation. For example, 100% or 300% of the tensile stress, etc., the more the tensile stress is, indicating that the force required for deformation is greater.

(7) Hardness
It is measured by a Shore hardness tester, which is expressed by the depth of the stylus pressed into the sample to be tested. The deeper the penetration depth, the smaller the hardness; the shallower, the greater the hardness, expressed in degrees of Shore A.

(8) Wear

There are several experimental methods. The commonly used Acron wear is based on the principle that the specified wheel sample (or the strip sample is firmly adhered to the wheel) and the specified grinding wheel are ground for 1.61km, and the volume of the sample is calculated. Expressed in cm3/1.61km. There is also the wear index representation, that is, the wear amount of the reference rubber is the numerator, and the wear amount of the test rubber is the denominator, the ratio is expressed in %, and the larger the value indicates the more wear resistance.

(9) fatigue life
It is common to deform the sample periodically under a certain periodic dynamic load, and the time for cracking or breaking of the material or product is expressed by the number of cycles, and of course there are other representation methods.

(10) Resistance to wet skid
It indicates that the rubber product is gripping on the water or wet road surface, and the wet skid resistance is not good, and it is easy to slip. If it is a tire, it is not easy to brake the car; if it is a sole, it is easy to slip.

(11) Rolling resistance
Mainly for tires or dynamically working products, the more resistant the rubber is, it means that the tread made with this glue is hot and has a large rolling resistance. Of course, the fuel consumption of the car is large.

(1) Mooney viscosity

The Mooney viscometer is used to measure the viscosity of the rubber body. The principle is to fill the mold between the cavity and the rotor of the viscometer, close the mold, and preheat it at a certain temperature (100 ° C) (1 min). The torque value (Nm) measured by rotating the rotor for a certain period of time (4 min). The larger the value, the greater the viscosity of the compound, which is usually expressed by ML (1+4) 100 °C.

(2) Mooney scorch

This is an indicator indicating that the rubber is burnt in the crucible. It is usually measured at 120 ° C (with a vulcanization system compounding agent). From the lowest point, it rises by 5 Mooney values ​​(the root can also take other rising values) time. The longer this time, the less likely the rubber is to be scorched and the safer the processing.

(2) Mooney scorch

This is an indicator indicating that the rubber is burnt in the crucible. It is usually measured at 120 ° C (with a vulcanization system compounding agent). From the lowest point, it rises by 5 Mooney values ​​(the root can also take other rising values) time. The longer this time, the less likely the rubber is to be scorched and the safer the processing.

(3) Plasticity

There are several methods of measurement, commonly used are Vickers plastometers and fast plastometers. The Vickers plasticity is obtained by compressing an unvulcanized cylindrical rubber sample between two flat plates at a predetermined pressure. After a certain period of time at a certain temperature, the external force is released, and after a certain period of time is restored, the height is measured. Taking the unrecoverable twist as the numerator, the sum of the height of the original twist and the load compression is the ratio of the denominator. The larger the value, the larger the plasticity.

(3) Plasticity

There are several methods of measurement, commonly used are Vickers plastometers and fast plastometers. The Vickers plasticity is obtained by compressing an unvulcanized cylindrical rubber sample between two flat plates at a predetermined pressure. After a certain period of time at a certain temperature, the external force is released, and after a certain period of time is restored, the height is measured. Taking the unrecoverable twist as the numerator, the sum of the height of the original twist and the load compression is the ratio of the denominator. The larger the value, the larger the plasticity.

(4) Tensile strength

Take the specified dumbbell-shaped sample, usually stretched to break at a speed of 500 mm/min, and calculate the force per unit area in the original section when unstretched, expressed in MPa.

(5) elongation at break

Tensile strength The ratio of the length of the sample stretched (excluding the original length) to the original working length when stretched in %