The fiber closure is the only protection unit for fiber optic cable connections and fiber connections, and plays an important role in fiber optic cable transmission lines. Most of the failures of the fiber optic cable line are due to the poor quality of the fiber optic connectors due to the poor quality of the fiber optic connectors. The factors that affect the quality of the fiber optic pallet include the sealing strength, the enclosure and the cable end seal, and environmental factors. The strength of the shell is the important factor that affects the quality and service life of the fiber connector, and the choice of the sealing material is the most important reason to affect the sealing strength of the fiber connector.
Under normal circumstances, the current domestic and foreign production of fiber closure shell material, the most commonly used two materials: PC (polycarbonate) engineering plastics and PP (polypropylene) plastic. Due to the different characteristics of the two kinds of plastic, the use of fiber closure is also different. Therefore, the use of PC material to join the capsule, because of its good weather resistance and flame resistance, making it more suitable for antenna, electrode and wall installation; due to its poor resistance to stress cracking, high temperature water easily decomposed, it is not suitable for pipe wells And buried installation. The use of PP material to join the capsule, because of its excellent chemical resistance and hydrolysis resistance, more suitable for pipeline wells and buried buried; due to bad weather, poor aging capacity, it is not suitable for antenna, poles and wall installation.
MPP is more popular as a fiber closure because it retains the characteristics and benefits of PP, but after adding glass fiber / mineral and other materials, it has achieved good mechanical properties and compensates for the above-mentioned drawbacks. World famous manufacturers such as 3M, TE, using MPP as a capsule material. However, in cold regions or countries such as Eastern Europe, Northern Europe, and northern China, the fiber cover made of PC (polycarbonate) will be better due to its good mechanical properties and good cold resistance.