The ordinary PTFE tube will be ruptured under the pressure of about 40kg/cm2. When it is combined with the steel wire, the pressure resistance is greatly improved, and the maximum working pressure in foreign countries reaches 700kg/cm2. Studies have shown that the compressive strength and pulse strength of the hose are not only related to the strength of the steel wire, but also to the size of the braiding angle. When the weaving angle of the single layer weaving is 54° 44′′, the steel wire does not elongate under the internal pressure, and the length and diameter of the hose do not change, and the pressure resistance is the best.
When used as a hose for aerospace industrial hydraulic systems, in order to prevent static breakdown of the inner tube due to the flow of hydraulic oil, a small amount of conductive carbon black must be added during the manufacture of the PTFE inner tube. However, studies have found that the addition of carbon black does not completely prevent static electricity from discharging through the tube wall and increases voids.
In the 1960s, Attas manufactured a composite tube, in which the inner layer of the tube was a uniform mixture of conductive carbon black and PTFE, and the outer layer of the tube was pure PTFE. This form of inner tube layer has axial electrical conductivity, so it can remove static electricity and prevent seepage.
Inner layer resin (including conductive carbon black), outer layer resin → compact → push → dry → cooling → inspection → weaving → fitting → inspection.
PTFE steel wire composite hoses are mainly used in hydraulic systems, air-conditioning systems, fuel systems, and oil systems on aircraft. In the civil industry, it is suitable for rubber, plastic, pharmaceutical, clothing, shipbuilding, automotive, machine tools, motors, diesel, paper and other industries for hydraulic, steam pressure, steam delivery and other soft connectors.