This is what we need to know about what kind of medium the hose is used to convey. When the medium is clear, there is a clear definition of the material of the hose. If we usually choose to transport water and gas, we immediately think of water pipes and air pipes (special pipes, matching materials). These are some common needs. If you are transporting media such as chemicals and steam, you need to be very careful.
Based on this, we need to understand some commonly used rubber materials, which is the key to our correct selection. Next, I will introduce some commonly used rubber materials and their characteristics one by one, hoping to help you.
First, natural rubber (NR)
Natural rubber is a kind of polymer elastic material collected from plants and processed. In nature, there are about 2,000 kinds of plants containing rubber components, but the Brazilian rubber tree has industrial application value (that is, high rubber content, high yield, high quality) and is easy to collect. At present, more than 98% of the world's total natural rubber production is sourced from the Brazilian rubber tree. At present, the most widely used is standard rubber (SMR), which accounts for more than 90% of natural rubber production. China's natural rubber production and consumption are now fourth in the world.
Basic characteristics:
1. Natural rubber is unsaturated rubber, it is easy to undergo vulcanization reaction with vulcanizing agent, and oxidize and crack with oxygen and ozone, and has poor aging resistance. With chlorination and bromination reaction with halogen, cyclization reaction occurs under the action of acid or catalyst.
2. Natural rubber has good physical and mechanical properties and high elasticity.
3. The raw rubber of natural rubber also has better elasticity at normal temperature, but it will gradually soften with heating, and the plasticity will become better and better; when its temperature gradually decreases, it will gradually harden and the temperature will drop to 0 ℃ As a result, its elasticity is greatly reduced. When the temperature drops below -70 ~ -73 ℃, it becomes brittle like glass. The phenomenon that raw rubber becomes soft when heated and hardened when cold is reversible, that is, it has thermoplasticity.
4. Natural rubber also has high mechanical strength and good resistance to bending fatigue.
5. Natural rubber has small hysteresis loss, high tear resistance, low deformation heat generation, excellent cold resistance and abrasion resistance, water resistance and air tightness, heat insulation and electrical insulation properties are also very good;
6, alkali resistance and resistance to general acid performance is better (but not concentrated acid and strong acid).
7. Natural rubber has excellent processing technology and is easy to be plasticized, mixed, calendered, extruded, molded and pasted. In addition, natural rubber is also easily dissolved in organic solvents such as gasoline and benzene to make glue. Natural rubber can be vulcanized with ordinary sulfur.
Application:
From the perspective of comprehensive performance, natural rubber is the best among rubbers. Natural rubber is commonly used to make various non-oil hoses, tapes, rubber pads, rubber capsules and various miscellaneous parts, various vibration-damping parts, electrical equipment insulators, medical and health products, sports products, and various daily necessities such as raincoat , Rain boots, hot water bottle, etc.).