The Difference Between (NR) Natural Rubber Bearing and (CR) Chloroprene Rubber Bearing
In recent years, many rubber bearings have been used on bridges. Rubber bearings are made of natural rubber and synthetic rubber (chloroprene). In order to reduce its lateral compression deformation, steel or vinylon is added to the rubber to strengthen it.
(NR) Natural rubber bearing is made of natural rubber.
(CR) Chloroprene rubber bearing is made of chloroprene (chloroprene as the main raw material, through homopolymerization or copolymerization of a small number of other monomers) as the raw material.
(NR) Natural rubber bearing: applicable temperature +60℃∽-40℃.
(CR) Chloroprene rubber bearing: applicable temperature +60℃-25℃.
Natural rubber has the disadvantage of accelerating the aging of ozone, sunlight (ultraviolet rays), etc. Therefore, when using natural rubber bearings, the rubber bearings are usually placed in a steel basin-shaped container and a steel convex cover is added. Become a sealed rubber bearing. This kind of sealed rubber bearing can prevent the rubber from aging, can transmit pressure evenly, and is mostly used on bridges with larger spans.
The types of synthetic rubber include synthetic natural rubber, styrene rubber, butadiene rubber, butyl rubber, nitrile rubber, chlorovulcanized polyethylene rubber, urethane rubber, silicon (oxygen) rubber, fluorine (chemical) rubber, and polysulfide More than ten kinds of rubber and so on. Among them, butyl rubber and chloro-vulcanized polyethylene synthetic rubber are the most used in civil engineering. Generally, bridges with relatively small spans often use plate rubber bearings instead of steel plate bearings. According to the load, the structure of the rubber bearing is different for this kind of rubber.