PVC foam pipe
DATE：2022/9/12 8:56:52 / READ： / SOURCE：This station
PVC foam pipe
PVC foam pipe is a new product among PVC pipes developed in recent years. This foam pipe has two structural forms. -] One is skinned low foaming PVC pipe, the other is that the middle core is foamed layer, the inner surface 2 and the outer skin are UPVC layer, and the structure 3 is shown in Fig. 5-33. 5.4.8.1 PVC skinned low foam pipe the PVC skinned low foam pipe has many similarities with the PVC core layer foam pipe and the vinyl chloride rigid ordinary plastic pipe in Fig. 5-33 in cross-sectional structure: extruding the raw materials for molding and extruding an outer layer of PVC hard layer; 2-pvc core layer forming equipment and production process basic foam layer; 3-The inner layer is the same on the PVC hard layer, except that a certain proportion of blowing agent is added to the raw material combination formula. Coating compound production line www.handern.com
In the process of extrusion molding, because the straight part of the mandrel in the molding die is slightly longer and the process conditions are changed, the inner and outer walls of the pipe are skinned to form a low foaming PVC pipe. The properties of PVC skinned low foaming pipes are basically similar to those of general PVC rigid pipes, but such pipes have the characteristics of low density, easy secondary processing and relatively low price. At present, it is mostly used as a drain pipe and a wire sleeve. Coating compound production line www.handern.com
(1) The extrusion molding of PVC skinned low foaming pipe is selected as the raw material. The main material is suspension PVC resin. The average polymerization degree of PVC used is p-800-1000, that is, SG5, SG6 and SG7 PVC resins. Then, a certain proportion of stabilizer, lubricant, foaming agent and other auxiliary materials and fillers are added to form the material formula. The reference scheme for the proportion of main materials in the formulation of PVC skinned low foam pipe forming materials is as follows (parts by mass). Polyvinyl chloride (SG5 or SG6) 100 other additives (acrylic resin ACR, 5-10 chlorinated polyethylene CPE and methacrylate stabilizer (trisalt or bisalt) lubricant (lead stearate or stearic acid, etc.) 2 ester butadiene styrene copolymer 8mbs and other fillers (calcium carbonate CaCO) blowing agent (Azodicarbonamide AC) 0.5 film coating composite production line www.handern.com
(2) The process route and auxiliary equipment of the extruder used for the extrusion molding of the equipment Part b-junction foam pipe are basically similar to the process route and auxiliary equipment used for the extrusion molding of the rigid PVC pipe, except that the structure of the molding die is slightly different. At present, twin-screw extruders are mostly used for the selection of extruders. Parallel twin-screw extruders or conical (counter rotating) twin-screw extruders can be used.
The mold structure is different from the mold structure for rigid PVC pipes in that the straight section of the mandrel for forming the crust low foaming pipe blank is slightly longer than the die, and its function is to improve the crust quality of the inner wall of the pipe; When necessary, compressed air can be blown into the tube blank, which is also to improve or remedy the crust quality of the inner wall of the foaming tube. Coating compound production line www.handern.com
(3) Molding process for raw materials for forming PVC skinned low foaming pipes, attention should be paid to the feeding sequence of raw materials during mixing: ① first, PVC resin, stabilizer and lubricant are added into the mixer in sequence, and then mixed for 30min. When the raw material temperature reaches about 110 ℃, stop the mixer for heating; ② Add the mixture of foaming agent and nucleating agent (i.e. filler) into the mixer and stir for 10min; ③ Put the evenly mixed raw materials into the cold mixer, and lower the temperature of the mixed materials to below 40 ℃; ④ Put it into the extruder to extrude the low foaming pipe with crust. Coating compound production line www.handern.com
The process temperature for extruding low foaming tubes with crust by single screw extruder is 130 ~ 160 ℃ in barrel feeding section, 170 ~ 180 ℃ in plasticizing section and 175 ~ 185 ℃ in homogenizing section. Forming die
170 ~ 180 ℃, 140 ~ 150 ℃ at the discharge end of the mandrel.
PVC foam pipe is a new product among PVC pipes developed in recent years. This foam pipe has two structural forms. -] One is skinned low foaming PVC pipe, the other is that the middle core is foamed layer, the inner surface 2 and the outer skin are UPVC layer, and the structure 3 is shown in Fig. 5-33. 5.4.8.1 PVC skinned low foam pipe the PVC skinned low foam pipe has many similarities with the PVC core layer foam pipe and the vinyl chloride rigid ordinary plastic pipe in Fig. 5-33 in cross-sectional structure: extruding the raw materials for molding and extruding an outer layer of PVC hard layer; 2-pvc core layer forming equipment and production process basic foam layer; 3-The inner layer is the same on the PVC hard layer, except that a certain proportion of blowing agent is added to the raw material combination formula. Coating compound production line www.handern.com
In the process of extrusion molding, because the straight part of the mandrel in the molding die is slightly longer and the process conditions are changed, the inner and outer walls of the pipe are skinned to form a low foaming PVC pipe. The properties of PVC skinned low foaming pipes are basically similar to those of general PVC rigid pipes, but such pipes have the characteristics of low density, easy secondary processing and relatively low price. At present, it is mostly used as a drain pipe and a wire sleeve. Coating compound production line www.handern.com
(1) The extrusion molding of PVC skinned low foaming pipe is selected as the raw material. The main material is suspension PVC resin. The average polymerization degree of PVC used is p-800-1000, that is, SG5, SG6 and SG7 PVC resins. Then, a certain proportion of stabilizer, lubricant, foaming agent and other auxiliary materials and fillers are added to form the material formula. The reference scheme for the proportion of main materials in the formulation of PVC skinned low foam pipe forming materials is as follows (parts by mass). Polyvinyl chloride (SG5 or SG6) 100 other additives (acrylic resin ACR, 5-10 chlorinated polyethylene CPE and methacrylate stabilizer (trisalt or bisalt) lubricant (lead stearate or stearic acid, etc.) 2 ester butadiene styrene copolymer 8mbs and other fillers (calcium carbonate CaCO) blowing agent (Azodicarbonamide AC) 0.5 film coating composite production line www.handern.com
(2) The process route and auxiliary equipment of the extruder used for the extrusion molding of the equipment Part b-junction foam pipe are basically similar to the process route and auxiliary equipment used for the extrusion molding of the rigid PVC pipe, except that the structure of the molding die is slightly different. At present, twin-screw extruders are mostly used for the selection of extruders. Parallel twin-screw extruders or conical (counter rotating) twin-screw extruders can be used.
The mold structure is different from the mold structure for rigid PVC pipes in that the straight section of the mandrel for forming the crust low foaming pipe blank is slightly longer than the die, and its function is to improve the crust quality of the inner wall of the pipe; When necessary, compressed air can be blown into the tube blank, which is also to improve or remedy the crust quality of the inner wall of the foaming tube. Coating compound production line www.handern.com
(3) Molding process for raw materials for forming PVC skinned low foaming pipes, attention should be paid to the feeding sequence of raw materials during mixing: ① first, PVC resin, stabilizer and lubricant are added into the mixer in sequence, and then mixed for 30min. When the raw material temperature reaches about 110 ℃, stop the mixer for heating; ② Add the mixture of foaming agent and nucleating agent (i.e. filler) into the mixer and stir for 10min; ③ Put the evenly mixed raw materials into the cold mixer, and lower the temperature of the mixed materials to below 40 ℃; ④ Put it into the extruder to extrude the low foaming pipe with crust. Coating compound production line www.handern.com
The process temperature for extruding low foaming tubes with crust by single screw extruder is 130 ~ 160 ℃ in barrel feeding section, 170 ~ 180 ℃ in plasticizing section and 175 ~ 185 ℃ in homogenizing section. Forming die
170 ~ 180 ℃, 140 ~ 150 ℃ at the discharge end of the mandrel.
Author：admin