Electrical conductivity
What is electrical conductivity of rubber? Electrical conductivity can be useful in elastomers if an electrostatic charge is to be avoided in the application. Vulcanizates can be made conductive during production by adding suitable additives, such as conductive carbon black. These additives are also called antistatic agents and are classified according to heteroatom into N-, […]
Swelling
What is rubber swelling? If elastomers remain in certain liquid or gaseous media for a longer period of time, the properties of the rubber can change depending on the material. The most noticeable change can be seen in the volume or mass. However, a change in tensile strength and Shore hardness can also occur. Depending […]
Chemical resistance
What is chemical resistance? Different rubber compounds are susceptible or resistant to different media. The typical risk contact media include oils, solvents, acids, bases, gases and water vapor. Depending on the area of application and potential contact media, the rubber material should be selected with care. According to DIN 53521, the extent to which the […]
Cold resistance
What is cold resistance? At very low temperatures (-20 °C and below), elastomers can harden and lose their special properties of elasticity, pressure resistance and tensile strength. If rubber parts are used at these temperatures, cold resistance is particularly important to ensure continued functionality. For example, good cold resistance can be achieved with silicone rubber, […]
Fatigue
What is fatigue? Fatigue describes the condition in which the rubber becomes limp and exhausted due to constant strain. It is a special form of ageingwhich is not caused by external influences, but simply by constant stress.
Rebound resilience
What is rebound resilience? Rebound resilience is a measure used to describe the damping of rubber components. It describes the percentage by which the test specimen moves away from the elastomer is pushed back by the elastomer. A high value means low damping. Flummis (rubber balls) are known in everyday life for their very high […]
Ageing
What is ageing? Ageing, i.e. the change (usually deterioration) of physical and chemical properties over a long period of time, occurs in all rubber. As rubber is an organic product, it is very reactive under certain influences, which can cause cracks or embrittlement. Typical triggers of ageing are heat, oxygen, ozone, moisture, mechanical stress and […]
Abrasion
What is abrasion? Abrasion corresponds to the removal of a material surface by mechanically occurring friction. The resistance of a material to abrasion is measured in a standardized manner and specified as an abrasion index. The rubber is clamped onto a roller and rolled against emery paper at a constant contact pressure. The volume loss […]
Synthetic rubber
Synthetic rubber Synthetic rubber refers to all elastomersthat are not natural rubber and is a product of organic chemistry. It is produced from heavy gasoline (naphtha), which is obtained from crude oil in a refinery. The building blocks (monomers) of heavy petrol are polymerized and then converted into rubber by vulcanization. The monomer (smallest molecular […]
Vulcanization
What is vulcanization? Vulcanization is the formation of cross-links between the individual polymer chains. polymer chains of the rubber when heat is applied. The produced natural– or synthetic rubber is initially only available as an uncrosslinked thermoplastic (plastic mass). The rubber gains its rubber-like properties through vulcanization. During the first vulcanizations(Charles Goodyear, 1839), sulphur chains […]
Damping
What is damping? The damping describes the energy loss of the vibration through a rubber article. Vibrations or impacts apply energy to the rubber-to-metal article, causing it to deform. When deformation occurs due to the application of force, the molecular chains of the rubber / elastomer rub against each other and thus “brake”. The energy […]
Settlement (permanent deformation)
What is settling? Pressure resistance refers to the resistance of a sample to pressure. It can therefore also be seen as spatial compactness. After removing the applied force elastomers are able to return to their original position. The distance that is lost in the expansion is also referred to as the compression set. The compression […]
Liability
What is liability? Adhesion indicates the strength with which two substrates adhere to each other. The substrates can be two elastomer surfaces or an elastomer and an adhesive film. Often the normal force is also referred to, which, depending on a unit area, is necessary to separate an adhesive film from the substrate. In a […]
Elasticity
What is elasticity? Elasticity describes the property after which deformation to return to its original position. As the name suggests, elastomers are elastomers are known for their high elasticity. You obtain these through vulcanization . The ability to bounce off a foreign body is called rebound resilience is called rebound resilience.
Shore hardness
What is Shore hardness? Shore hardness is a defined measurement that indicates the relative resistance of the surface to indentation by a defined body with a given load. The Shore A test is usually carried out with a truncated cone needle. The test is standardized in DIN ISO 7619, DIN 53505 or ASTM D 676. […]
History
History of rubber Discovery of the elastic material Long before the first European explorers reached the American continent, the indigenous peoples of Central America, such as the Aztecs and Mayans, knew about the sap of the “weeping tree”. They called the tree “caao-chu”, so that our rubber developed from the French word “caoutchouc”. They used […]
