PVC water supply pipe
DATE：2022/9/9 8:54:43 / READ： / SOURCE：This station
PVC water supply pipe
PVC (water supply) pipes are extruded with sanitary PVC grease and have the following characteristics. ① Non toxic, chemical resistant, not affected by chlorine or bleaching powder in water. ② It has strong water delivery capacity, small friction coefficient and small flow resistance to water.③ Compared with other plastic pipes, it has better aging resistance and weather resistance. It does not scale and rust when used in water temperature below 50 ℃ for a long time. ④ Non flammable, self extinguishing from the fire source ⑤ the pipe is easy to install and the price is relatively cheap. (1) PVC resin for drinking water pipe molding shall be selected as raw material. It shall be suspension pvcsg5 resin (k value is 68 ~ 70, average polymerization degree is 1000). The content of vinyl chloride monomer in the resin shall be less than or equal to 3mg / kg. The maximum allowable content of lead, cadmium and mercury in auxiliary material stabilizer and lubricant is 0.005mg/l. Reference formula (parts by mass) of the extruded tube by single screw extruder. Polyvinyl chloride (PVC SG5) 100 dibasic lead phosphite (2PbO). EVA film production line www.handern.com
Molding process of tribasic lead sulfate (3PbO) 3 lead stearate (PBST) 1 (2) ① production process of PVC conveying drinking water pipe outlet molding, whether the process is in accordance with a, PVC resin screening → metering of various raw materials in the formula → high-speed hot mixing of raw materials - cooling and stirring of raw materials
#→ extrusion granulation → extrusion and melting of raw materials → mold forming of tube blank → cooling and finalization → traction → cutting - quality inspection → weighing inspection warehouse B The production process sequence of forming pipes with twin-screw extruder (counter rotating meshing type) is as follows: PVC resin screening → metering of various raw materials in the formula → high-speed hot mixing of raw materials → cooling and mixing of raw materials → extrusion and melting with twin-screw extruder → mold forming of tube blank → cooling and finalization → traction → cutting-a quality inspection → weighing inspection warehouse ② raw material mixing and extrusion granulation production process conditions refer to Chapter 4. ③ Process temperature a The process temperature of single screw extrusion tube is 100 ~ 140 ℃ in barrel feeding section, 150 ~ 170 ℃ in plasticizing section and 160 ~ 180 ℃ in homogenizing section. The molding die temperature is 170 ~ 190 ℃. b. Process temperature of twin screw extrusion tube
The process temperature of the counter rotating meshing twin-screw extrusion molding pipe is 130 ~ 160 ℃ in the feeding section, 150 ~ 155 ℃ in the plasticizing section and 160 ~ 170 ℃ in the homogenizing section. Molding die 170 ~ 180 ℃. EVA film production line www.handern.com
The process temperature of conical twin-screw extrusion tube is 180 ~ 195 ℃ in the feeding section, 170 ~ 180 ℃ in the plasticizing section and 170 ~ 175 ℃ in the homogenizing section. The molding die temperature is 170 ~ 190 ℃. (3) Quality requirements GB / t100021996 specifies 52 the dimensions of rigid PVC water supply pipes. The rigid PVC standard refers to the number of rigid PVC force repair coefficient systems under different pressure conditions and different temperatures when the conveying water temperature is 20 ℃. The allowable bearing capacity of PV pipes when the conveying temperature is 25 is I. in the indicators specified in the sanitary standards for water supply pipes, it is required that the PVC pins and lubricants of formed pipes should be, The content of vinyl chloride monomer and the content of trace toxic metal are strictly controlled. See table 5-45 for the physical performance requirements of the rigid PVC pipe without B monomer content. See table 5-46 for mechanical property requirements of UPVC water supply pipe. Physical performance requirements of U-PVC water supply pressure pipe EVA film production line www.handern.com
In addition to the key points of extrusion molding Ding process of ordinary hard paste argon ethylene marriage pipe, we should also pay attention to the following points and build GB.
5-19. In terms of production cost, calcium carbonate filler can be appropriately added to the raw materials, but attention should be paid to the fineness of carbon and surface to control the chemical treatment of calcium. The density is appropriate, and some plasticizer is added to the raw material. ③ Note that the mold compression ratio of this melt is about 5: the split cone is between 60 and 90. The straight section of the core rod of the shaped tube blank should be longer, and the length is about twice the diameter of the tube; The length of the vacuum sizing sleeve is about 400mm. ④ The housekeeping time of the machine is shorter than that of the single screw extrusion, and the plasticizing quality is good, so the amount of stabilizer added in the material formula can be less than that of the single screw extrusion pipe. (5) The lower b-pipe type is the UPVC drainage pipe buried underground for urban drainage of domestic and industrial wastewater, which is different from the drainage pipe in the building in that the diameter of the pipe is relatively large. According to the national standard, the minimum diameter of buried drainage pipes is p110mm ① the raw materials and equipment for forming buried drainage pipes are basically the same as those for forming buried PVC drainage pipes and production equipment, which can be referred to. EVA film production line www.handern.com
However, due to the large diameter of pipes, twin-screw extruders are generally used for extrusion molding. A flaring machine is required in the production process to process the end of the plastic pipe. The main raw materials for forming buried drainage pipes are suspension PVC resin SG5, and the auxiliary materials are stabilizers, lubricants and other types. Reference examples of its composition (dark grey) are as follows (mass fraction). PVC (pvcsg5s1000) composite stabilizer) 2.8 stabilizer ogp-101 (lead stearate (PBST) 0.5 imported from Japan)
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