Polyethylene cable material (2)
DATE：2022/11/19 8:34:03 / READ： / SOURCE：This station
Polyethylene cable material (2)
(4) Key points of process operation① Raw materials for cable material pelleting can also be low-density polyethylene resin with a melt flow rate (MFR) of 2g/10min, mixed with polyisobutylene (PIB) or butyl rubber, and the mixing ratio of the two is LDPE/PIB=90/10.
② Carbon black in raw materials shall be carbon black produced by natural gas tank method. Note that carbon black should be mixed with PE resin evenly; It is better to use the masterbatch containing about 30% carbon black first, and then mix it with other materials. The uniformly mixed raw materials shall be brown, and no large black particles can be seen under the microscope at a magnification of 200 times.
③ When using the pelletizer to cut the material into granules for production, pay attention to the plasticizing quality of the raw materials. If necessary, appropriately extend the mixing time of the raw materials in the internal mixer and appropriately reduce the distance between the two roller surfaces in the open mill; The temperature of raw materials for two roll mixing shall be controlled within 170~210 ℃; The slice width and thickness after mixing shall be processed according to the requirements of the pelletizer.
④ When pelleting after plasticizing the raw materials with an extruder, it should be noted that the melt temperature of the plasticizing materials should not exceed 210 ℃.
⑤ The particle size of the finished cable material shall be 2~5mm, and the particles shall be uniform and uniform in size. The particles shall be free of impurities, bubbles and colors.
The quality of black polyethylene wire and cable material shall comply with GB15065-94 standard.
① The granular cable material is cylindrical, with a diameter of 3~4mm and a length of 2~4mm. It can also be cut into square particles with the same volume as the cylindrical cable particles by a granulator.
② Cable materials can be divided into sheath materials and insulation materials according to their uses. See Table 10-8 for specific requirements.
③ The appearance quality requirements of the cable material particles are: the particles are uniform, the surface is smooth, and there are no obvious impurities. More than 3 particles are not allowed to be connected.
④ The mechanical and electrical properties of the cable material shall comply with the provisions in Table 10-9.
⑤ The quality requirements of irradiated cross-linked polyethylene wire and cable materials shall comply with the provisions of QB/T2462.1-1999 standard.
a. Irradiated cross-linked polyethylene wire and cable insulation materials are divided into two categories: 0~10kV overhead cables and 0~10kV cables. The overhead cables are black irradiated cross-linked polyethylene insulation materials.
b. The insulation material code is: J stands for overhead, F stands for irradiation cross-linked material; YJ refers to cross-linked polyethylene insulation, and X refers to applicable voltage value (10 for 10kV and below). For example, JFYJ-10 represents black irradiated cross-linked polyethylene insulation material used for overhead cables of 10kV and below.
c. See Table 10-10 for the mechanical properties and electrical properties of irradiated cross-linked polyethylene insulation material.
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