The cable jacket is designed to accommodate many different complex climates and to ensure long-term (at least 25 years) stability. hose crimping tool. The cable sheath not only has a certain strength, but also has low thermal deformation, wear, water permeability, heat retraction and friction coefficient, as well as strong environmental stress resistance and good material processing performance. Although less used or poorly used sheathing materials can pass the factory acceptance, but due to quality defects, cracking and water seepage will occur after a period of use. If recycled plastic is used to replace high-quality polyethylene sheathing material, it is more serious. The cable made of high-quality sheath material has a smooth outer skin, bright, uniform thickness and no air bubbles. Otherwise, the skin of the optical cable will be rough, and because there are many impurities in the raw material, it can be found that the outer skin of the optical cable has many tiny defects. It is awkward, and because of its thin thickness, the entire outer diameter of the cable is much smaller than that of a high-quality cable. Indoor optical cable, generally made of high-quality flame-retardant PVC, the appearance should be smooth, bright, flexible, easy to peel; otherwise there will be poor skin finish, easy to tight and tight fiber, aramid adhesion.
Steel strip, aluminum strip.
The steel strip and the aluminum strip in the optical cable are mainly used to protect the optical fiber from mechanical side pressure and moisture, and a chrome-plated steel strip is generally used in a good optical cable. Inferior optical cable replaces chrome-plated steel strip with ordinary iron or black leather (no coated steel strip) that has been rust-proof only on one side. Over time, rust will appear in the cable, and the hydrogen loss of the fiber will be intensified. It is easy to separate from the sheath and does not form a comprehensive bonding layer. The moisture barrier performance is also very poor. Some of them replace the chrome-plated steel strip with a tin-plated steel strip. The surface of the tin-plated steel strip is inevitable. Therefore, under humid conditions and surface condensation or water immersion conditions, corrosion is prone to occur, especially under acidic conditions. The tin plating layer has poor heat resistance and the melting point is only 232 degrees Celsius. In the application, due to the high temperature during the extrusion of the sheath, the peel strength is uncertain, which affects the moisture resistance of the cable. The melting point of chromium is 1900 degrees Celsius, the chemical property is very stable, it is not rusted when placed in the air at room temperature or immersed in water, and the corrosion resistance is very good. Because the surface is easily oxidized to form a passivation layer, the environmental resistance is very good. In the case of aluminum strips, it is generally the case that unacceptable hot-adhesive coated aluminum strips replace the cast-coated aluminum strips, which also affects the performance of the cable.