Fiber Reinforced PVC Hose
DATE：2022/9/27 9:15:01 / READ： / SOURCE：This station
Fiber Reinforced PVC Hose
Fiber reinforced PVC hoses are basically the same as ordinary PVC hoses. They are also made of polyvinyl chloride resin as the main material, and then add a certain proportion of plasticizers, stabilizers, lubricants and other auxiliary materials to form the formula. Post extrusion.
The difference between the fiber reinforced PVC hose and the ordinary PVC hose is that there is a layer of mesh woven by chemical fibers in the pipe wall during extrusion molding, and the structure is shown in Figure 5-26.
Figure 5-26 Fiber-reinforced polyvinyl chloride pipe structure fiber-reinforced polyvinyl chloride hose, because the surface of the layer pipe is solidified into oneIts molding is formed by the combination of polyvinyl chloride-based multi-310-3-PVC plastic inner layer materials, and there are lattice chemical fibers in the middle to enhance the effect, so this plastic pipe has PVC in addition to it. In addition to the corrosion resistance, light weight and soft and bendable properties of the hose, it can also withstand a certain pressure during work. At present, it is widely used in the complete plasticization and uniformity of the conveying pipelines of bodies or liquids in industrial equipment and conveyors.
(1) Selection of raw materials
SG2, SG3 or SG4 resins in suspension PVC are used for forming fiber reinforced PVC pipes, and a certain proportion of auxiliary materials such as plasticizers, stabilizers and lubricants are added to form the formula.
Staying too long
Reference example (parts by mass) of the formulation of fiber-reinforced polyvinyl chloride pipe forming materials.
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Polyvinyl chloride resin (PVC SG3) 100 Barium stearate (BaSt) 1.0
Dioctyl phthalate (DOP) 28.0 Cadmium stearate (CdSt) 0.7
area, resulting in part of the material
Dibutyl phthalate (DBP) 22.0 Paraffin (P-CI) 0.2
(2) Forming process
①The production process sequence of fiber reinforced PVC pipe forming
The PVC resin and various auxiliary raw materials are measured according to the formula ratio → the raw materials are hot mixed in the mixer → the raw materials are cooled and stirred → the inner layer tube is extruded → cooled and shaped → fiber winding → traction → heating → extrusion of the outer layer of the clad pipe → Cooling and shaping → traction → coiling → inspection → weight inspection → packaging and storage
Flow to barrel side and raw material
② Equipment conditions
a. Mixer, used for mixing raw materials, can be a horizontal kneader or a high-speed mixer.
b. Two single-screw extruders, one extrudes the inner layer of the molding tube, the other extrudes the plasticizer in a certain proportion, and the outer layer of the molding tube, the screws are of equidistant and unequal depth gradient type, and the length-diameter ratio is 18~25, the compression ratio is 2.5~3.5. The specifications of the extruder are determined by the diameter of the extrusion tube.
c. The choice of the filament winding machine is determined by the specifications of the production pipe, and the number of spindles of the coil is selected according to the diameter of the pipe. When the diameter of the tube is not large, 16 yarns can be used, the number of spindles of the two coils is equal, the angle of the winding grid can be 60° or 90°, the working speed is about 2m/min, driven by a DC motor, the speed can be tune.
d. The heating method can be heated by resistance heating or hot air circulation. The function is to make the chemical fiber wound on the surface of the inner layer tube shrink by heat and stick to the outer surface of the tube; in addition, the surface of the plastic inner layer tube is heated and melted, which is conducive to the lamination of the outer layer of the tube and the outer surface of the inner layer tube, which is firm combined into one.
③Molding process
a. After the materials are measured according to the requirements, add PVC resin and additives to the high-speed mixer for mixing and stirring. The specific requirements are the same as the mixing method of PVC hose raw materials. When the temperature of the material reaches 110~120℃, put it into the cold mixer, stir and beat
Break up the agglomerated material and let the temperature of the mixed material drop below 45°C.
b. For the inner layer of the extruded fiber reinforced pipe, the temperature of the extruder barrel feeding section is 90~120℃, the temperature of the plasticizing section is 130~150℃, the temperature of the homogenization section is 160~170℃, and the temperature of the molding die is It is 170~180℃.
c After the inner layer of the fiber reinforced PVC pipe is cooled and shaped, the surface is wound with a grid, the chemical fiber wire specification is 210D/1x3, the grid angle is 60°, and the ingot core is 16 pieces.
d. The tube is heated, and the chemical fiber wire is shrunk and tightly wrapped on the outer circle of the inner tube. The outer surface of the tube is all wave-like, and the surface of the tube is required to be slightly molten.
e. For extruding the outer layer of the fiber-reinforced pipe, the temperature of the extruder barrel feeding section is 110~130℃, the temperature of the plasticizing section is 140~160℃, the temperature of the homogenization section is 160~170℃, and the temperature of the molding die is 110~130℃. It is 170~180℃.
(3) Quality requirements
The quality of fiber-reinforced polyvinyl chloride pipes has no domestic standards. Referring to the relevant information, provide some quality conditions of fiber reinforced PVC pipes, and provide reference for testing when supplying or producing raw materials.
① Appearance quality requirements
The inner and outer surfaces of the fiber reinforced polyvinyl chloride pipe should be smooth and flat, and no bubbles, unplasticized hard boils and impurities are allowed; the thickness of the pipe wall should be uniform; the color should be uniform, and the outer layer should generally be a transparent layer.
②The performance of fiber reinforced PVC pipe
Tensile strength>11.50MPa, peel strength ≥9.5N/cm, elongation at break ≥200%.
Hydraulic test: keep below 1.2MPa for 5min without breaking.
Cold resistance test: (-10 ± 2) ℃ for 5min impact without breaking.
5.4.7 PVC bellows
The difference between the PVC corrugated pipe and the ordinary PVC pipe is that the ordinary plastic pipe is changed from a smooth and flat outer circle to a corrugated shape, so that the corrugated pipe can be formed with less raw materials, and the rigidity and resistance of the plastic pipe can be improved. pressure. The structure of the bellows of the mold can be divided into single-wall bellows and double-wall bellows from the perspective of the longitudinal cross-sectional shape.
5.4.7.1 PVC single-wall corrugated pipe
The structure of the single-wall corrugated pipe can be seen from Figure 5-27, it is a corrugated plastic pipe with both inner and outer wall surfaces. The wall thickness of this kind of corrugated pipe is relatively thin, and it is mainly used for the exhaust pipe, the discharge water pipe and the threading pipe that require the pipe to be freely bent and do not need high working strength.
(1) Selection of raw materials
The raw materials for forming PVC single-wall corrugated pipes are basically the same as those used for extrusion molding of ordinary PVC rigid pipes. The suspension method PVC SG4 or SG5 is used to form resins, and then a certain proportion of stabilizers and lubricants are added. agent and some other auxiliary materials, which can be used or raw to make up the formula.
Reference example (mass parts) of the material formulation of polyvinyl chloride single-wall corrugated pipe.
Surface should be smooth Polyvinyl chloride resin (PVCSG5) 100
Barium Stearate (BaSt)
Tribasic lead sulfate (3PbO)
Acrylic resin (ACR201)
Dibasic lead phosphite (2PbO) 1.5
Calcium carbonate (CaCO;)3
Lead stearate (PbSt) 1.5
Stearic acid (HSt) 1.5
(2) Equipment conditions The equipment for extrusion molding of PVC single-wall corrugated pipes is basically similar to the equipment conditions for extrusion molding of ordinary PVC pipes. The difference is that a set of corrugated molds for forming pipes is added before the molds for forming corrugated pipe blanks. The working structure of this blow molding tube corrugated mold is shown in Figure 5-29.
As can be seen from Figure 5-29, the structure of the mold for forming the corrugations of the blow molding tube works like a bicycle chain. The chain link is equipped with a mold for forming the corrugated pipe. There are dozens of pairs of molds, which are split up and down (or left and right), and are driven by the chain to complete the closing and opening of the two half-open molds (Figure 5-30). When the two halves of the mold are closed, a cavity for blow molding bellows is formed; when the two halves of the mold are opened, the surface of the tube is corrugated, and the bellows is demolded. The running action of the forming corrugated die also plays the role of pulling the corrugated pipe forward.
Figure 5-29 Composition of corrugated forming mold
Figure 5-30 Forming of corrugated mold
Camp or rigid PVC and work operation instructions Closed operation work instructions
1- drive sprocket; 2- drive chain;
2- 1- Mold for forming corrugation; 2- Transmission sprocket;
3-Forming corrugated mold 3-Corrugated tube blank forming mold
(3) Forming process
① Production process route of corrugated pipe extrusion molding
Polyvinyl chloride resin is sieved with a 40-mesh sieve → various raw materials are measured according to the material formula for bellows molding → high-speed mixing and stirring of raw materials → raw materials cooling and stirring → extruder extruding plasticized raw materials → molding bellows pipe extrusion molding Use tube blank → blow molding tube corrugation, cooling and shaping → cutting → flaring → inspection and storage
②Raw material preparation and treatment process temperature High-speed mixer mixes various raw materials evenly, it is recommended to use double-material temperature of about 115 ℃; the mixed high-temperature material needs to be cooled in a cold mixer, and the material temperature should not be higher than 45 ℃.
③Single-screw extruder extrusion process temperature barrel feeding section 130 ~ 150 ℃, plastic
The temperature of the bellows section is 150~170℃, and the homogenization section is 170~185℃. The temperature of the mold for forming the tube blank is 170~180℃.
(Figure 5-32)
④ Working conditions of corrugated mold for forming pipe The flow cone and two running speeds of the corrugated mold for plastic pipe blank forming are generally within 10m/min. Spray or blow cold air to cool the mold.
Chapter 5 Plastic Tube Extrusion
5.4.7.2 PVC double-wall corrugated pipe
The structure of the PVC double-wall corrugated pipe can be seen from Figure 5-28. This corrugated pipe is a smooth and flat surface with a corrugated outer circle and an ordinary straight pipe shape in the inner circle. Fusion into double wall bellows.
Compared with the single-wall corrugated pipe, the working strength and rigidity of the double-wall corrugated pipe are higher than that of the single-wall corrugated pipe, and because its inner pipe wall is smooth and flat, the resistance of the conveying liquid is small, and there will be no impurities in the conveying sewage. or suspended solids deposition. But because of the inner wall tube, this kind of tube is not as easy to bend as the single-wall corrugated tube.
The use of double-wall corrugated pipe is very similar to that of single-wall corrugated pipe. Because this pipe is large in diameter, it is mostly used in well pipes, farmland water conservancy irrigation pipes, construction engineering pipes and cable casings that require high strength for conveying liquids. .
(1) Raw material selection
The raw materials for forming wall corrugated pipes or rigid PVC pipes are exactly the same. The raw material composition of the formula can adopt the formula of PVC pipe materials (mass parts).
PVC SG5 type resin Impact resistance agent (acrylic resin ACR) 7~12 100
Stabilizer 5~7 Filler (Calcium Carbonate, CaCO) 8~12
Lubricant (CPE) 2~3 Processing aid Appropriate amount
(2) Equipment conditions Extrusion molding equipment and single-wall PVC double-wall corrugated pipes
The equipment for forming corrugated pipes from various raw materials is basically similar, and the only difference is the forming mold for the pipe blank.
However, since the double-wall corrugated pipes are mostly large-diameter specifications, there are many raw materials for extrusion molding, and the mixing is uniform, so it is recommended to use a twin-screw extruder (parallel or conical twin-screw extruder can be used).
Figure 5-31 shows the structure of the blank forming mold for double-wall corrugated pipes.
The structure of the tube blank forming die of the double-wall corrugated pipe and the tube blank forming die of the single-wall corrugated pipe 150℃
The difference in structure (Figure 5-32) is: the straight section of the mold forming tube blank is longer; there are two melt distribution cones and two layers of melt runner cavities. The inner and outer layers of the double-wall corrugated pipe are formed separately; there is also a compressed air inlet channel in the middle of the inner and outer melt runners, and the compressed air entering here inflates the outer layer pipe wall, making it close to the corrugated mold. The corrugated shape of the forming tube; the central hole of the inner mandrel can place a heater, and there are through holes for compressed air and cooling water.
Figure 5-31 The structure of the tube blank forming die for the double-wall corrugated tube
1-perforated plate; 2-mold body; 3-split cone support; 4-middle sleeve: 5- gland; 6-outer tube wall forming die; 7-outer layer tube wall forming mandrel; 8-inner Layer tube wall forming die; 9- inner layer tube wall forming mandrel; 10- heater hole; 11- compressed air entering through hole; 12- inner wall melting material; Vinyl Double Sheet 5-59
Figure 5-32 Tube blank forming die structure of single-wall corrugated pipe
1-perforated plate;2-mold body;3-adjusting screw;4-split cone;5-lock nut;6-die;7-air blocking rod;8-mandrel;9-intake pipeline
It can be seen from the structure diagram of the two molds that the structure of the two molds is the same: there should be a porous plate in front of the melt distribution cone, and the wall thickness of the tube blank is adjusted by adjusting the movement of the distribution cone and the mandrel to adjust the core. The size of the gap between the rod and the die, and the die cannot move due to the extension between the two halves of the corrugated die.
(3) Molding process The extrusion molding process of the PVC double-wall corrugated pipe is basically the same as the extrusion molding process of the PVC single-wall corrugated pipe, and the production can be referred to. If a parallel twin-screw extruder is used for forming the PVC double-wall corrugated pipe, the reference value of the process temperature for forming the double-wall corrugated pipe by the extruder is shown in Table 5-56.
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