In the field of transmission fluid medium, polyethylene (PE) pipes widely respected in recent years and has been the rapid development of new bearing structure. A pipe with the traditional gold compared to polyethylene piping systems with light weight, than strength and specific rigidity, durability, corrosion resistance, insulation, composite capability and strong resistance to fracture. Ease of production and installation, low cost, its typical service life of metallic green several times and can save a lot of production and use of energy. It can be used for urban water supply and drainage and gas transmission and distribution system, agricultural irrigation systems, ventilation systems and mud factories, mines, ore pipeline transportation and other fields.
Polyethylene piping systems in the manufacture and laying, pipe connection between the impact strength of its structural integrity and durability of the important aspects. Since polyethylene molecular chain composed of the methylene and has a high degree of symmetry. Determines its polarity is low, so polyethylene pipe connection will not be using solvent bonding method, only mechanical connection or welding. Practice table squat, welding is a high quality, high efficiency plastic pipe connection technology. The relatively mature technologies, including welding socket welding, butt welding, fusion welded. Which belongs to the heating wire melting fusion welded butt-welding, because the construction is simple, portable field equipment, welding speed, and soon obtained the development and promotion. The basic principle is the high-resistance wire Xu first person buried in the plastic casing wall. After docking, Walter current, electric wire heating temperature to the surrounding plastic to melt and blend with each other, after cooling to form a weld.
Using carbon felt with polyethylene laminated composite conductive composites prepared as fusion welded materials are practical composite material during power change in resistivity is very small, can be stably heated to the melting temperature of polyethylene. Composite material forming process parameters for the temperature degree 160 ℃, time of 10 min, pressure of 10 MPa, the composite resistance control 10 a 100 Ω. Factors affecting weld strength fused with heating power and heating time, the weld strength of their principal attributed to the temperature of the heating layer, while controlling the temperature of the heating layer 140 is within a range of 220 ℃, obtain the ideal welding strength. Therefore, the different input power can select the appropriate heating time to achieve the desired welding effect. Electrofusion welding, the heating layer exists near the heat affected zone, the molten layer and the heat-affected zone, polyethylene crystallinity, crystal size will change, and thus affect the performance of the material.
Post time: Jan-04-2021