XLPE factors from the head extrusion cooling process that could cause the insulated core surface quality problems:
(1) cat7 cable surface with a bubble, when the cable into the water, the bubbles adhered to the surface if there will be "pit package" After the position of the cooling, this is because the air bubbles coated on the insulating surface, covering the bubble part of the cooling rate slower than the portion in contact with water. Reasons for the formation of bubbles cat7 cable attached to the surface of the flow rate is generally used for circulating cooling water into the sink fast, strong currents, high-speed flow of air into the water, part of the air attached to the cable surface, forming bubbles; (2) before entering the cooling water has droplets splashed on the cable surface, in contact with water to cool part of the contract, but some also in contact with air at high temperature state, due to differences in the cooling rate of forming an insulating core uneven surface phenomenon.