Classification of regular copolymerized polypropylene
DATE：2022/9/2 9:29:40 / READ： / SOURCE：This station
Classification of regular copolymerized polypropylene
In addition to light weight, non-toxic, corrosion resistance and high strength of polypropylene pipes, the pipes extruded with random copolymer polypropylene resin have low temperature and impact resistance
The comparison of the clothing of the whole and two explosive trees of different grades
Good, the circumferential stress under high temperature conditions is better stable at 61mpa than other polypropylene pipes, and the service life is more than 50 years. It has good thermal insulation during hot water transmission, smooth inner wall of the pipe, small liquid flow resistance, etc
It is difficult to process the pipe after melting. However, due to the low melt flow rate of the resin, the viscosity of the melt is large
This structure
(2) Non polypropylene resin with ethylene content of about 3% (by mass) shall be selected as the material for extrusion molding pipes under the condition of resin for random polypropylene pipe type. It is in granular form and the density is within the range of 0.89 ~ 0.91g/cm
Parameter values shall meet the conditions in table 5-35. The melt flow rate (MFR) is less than 05g / 10min
(3) the extrusion molding process is the same as the extrusion molding process of ordinary polypropylene pipes. The single screw general-purpose extruder is used. The raw materials are extruded from the molding die after extrusion and melting, and then cooled and shaped by the vacuum sizing method. After the pipe material is cooled by sufficient spray water, it is cut according to a fixed length. Thus, the extrusion molding production of the random copolymer polypropylene pipe is completed. Due to the thermal conductivity of the random copolymer polypropylene resin Low, high molecular weight, low melt flow rate, that is, the viscosity of the resin in the molten state is high, so it needs more heat from the crystal to the high elastic state and then to the molten viscous flow state in the extrusion process, that is, the consumption of electric power is soft and large; The transformation process of raw material form also has some special requirements for the structure of the equipment
Cai Hanfang's structure is a gradual variant with equal cuttlebone spacing and unequal depth, and the length diameter ratio is greater than the range ratio
The raw material can be helically pushed by the screw into the hole of the front transfer treatment center, and the cooling water is supplied to facilitate the working temperature of the screw
The inner hole working face of peach slips is different from that of ordinary machine slips
There are longitudinal grooves evenly distributed on the circumference to increase the thickness of the material and improve the forward transport capacity of the material after entering the machine. The length of the longitudinal groove is about 3-4 times of the inner diameter of the machine barrel. The random copolymer polypropylene pipe with the mold structure for force sensing and use shall be formed by basket or
3mm mold (see Fig. 5-16 for blue structure mold), the cavity of melt channel is no longer than 21, and the length of the straight part of the shaped section is longer than that of ordinary polypropylene
The contraction angle of Italian mandrel shall not be too large. The length of the straight part of the shaping section is larger, and the inner diameter of the die is larger than the inner diameter of the sizing sleeve
The length of the vacuum sizing sleeve of the common polypropylene tube blank is large, and the specific length shall be determined by the size: for example, when the diameter of the production pipe is 30mm, the vacuum sizing shall not be less than 350mm. The vacuum degree in the air stator sleeve shall be controlled within a range of - 0.09. The temperature of cooling circulating water in the vacuum jacket shall be adjustable and the water temperature shall be around 35 ℃. The length of spray water tank is longer than that of common polypropylene pipe for cooling and temperature reduction
Front length: when the diameter of production pipe is 30mm, the length of spray water tank shall not be less than
When the diameter of the total production pipe is 50mm, the length of the spray water tank shall not be less than 12m. Spray water energy
In this way, the temperature control of the cooling water is more convenient. The length of the spray water tank can be up to 30m when the random copolymer polypropylene is discharged from the molding production line.
The circulating water temperature in the pouring water tank is generally controlled at about 17 ℃. The water temperature of each section of the water tank shall be controlled from entering the spray water tank after the pipe blank sizing and gradually decreasing.
The inner diameter of the vacuum sizing sleeve should be slightly larger than the outer diameter of the forming pipe, but slightly smaller than the inner diameter of the die in the forming.
At present, most of the domestic production lines of random copolymer polypropylene tube extruders are imported, with high degree of automation, set, recorded and controlled by computers; An electric meter is installed at the feeding port, and a far-infrared measuring device is installed at the back of the calibrating sleeve to measure the diameter and wall of the pipe
The work of the wrong Meijiang rod of the friction ruler and the positive pipe ruler is built in 45 / Mn d185 ~ 200. The temperature is controlled within the range of 210-240 ° C. the electric system is 8222250, and the fifth zone is 230-2507
When the spring is attached to the road at the fitting place of the shoushouhui warp, a cooling water ring should be set before the sizing sleeve, and the degree of alcohol can be adjusted. The water temperature control of this warp should be subject to the tube blank cooling down to the non stick mold. The phenomenon of pulling the spirit and orientation and the stress of the shadow ring lead to the pressure resistance of the pipe when it is working. The spray water temperature of the cooling water concentrate in Xiatian is controlled within the range of 15 ~ 18 ℃. Excessive water temperature
It will produce high internal stress and affect the quality of pipes. If the particles of the non-conforming products are large, the impact resistance will decrease; The water temperature is too low, after the pipe is finalized
The waste materials produced in production can be directly used in production after being crushed, dried and cleaned. However, the amount of admixture should not be too large and should not exceed 7%
It is appropriate to avoid affecting the quality of pipes.
(5) it is used in the winter construction industry. The maximum operating temperature for conveying hot and cold water can reach 95 ℃, and the long-term operating temperature is 70 ℃; in industrial production, it can be used for conveying oil and various corrosives
It will not pollute the environment. The service life can reach more than 50 years. Liquid; In people's daily life, it is used in drinking water and agricultural irrigation. It is non-toxic
The application characteristics of random copolymer polypropylene pipe are as follows.
① PP-R pipe body is light, non-toxic, corrosion-resistant, good strength, no pollution to the environment and long service life.
② Compared with ordinary metal pipes, PP-R pipes are free from corrosion, abrasion, scaling and acid and alkali resistance.
③ PP-R pipe has small resistance to liquid transportation and good thermal insulation performance for hot water transportation, which can save energy.
Compared with the production process of cross-linked pipe B, the Tiantian process has no pollution to the production ring splitting, and is easy to operate. The Luoxuan process has been used for a long time
Misclassification of size
Fast, reliable application and good sealing. Tianlu installation method: single hot melt installation of the same material
Conditions: 185-200t huazhan West explosive clothing field irrigation pipe area 230-260% chongchen propylene field irrigation pipe is a kind of plastic pipe with light weight, non-toxic, rust free and high resistance. When applying water conveyance in farmland irrigation, it can withstand this temperature control
Pressure (up to 0.5MPa), and can withstand a certain amount of kangdi-i tube blank outer garment
Pipe suitable for farmland irrigation. It is a kind of material with good low temperature resistance and aging resistance, and also has certain toughness
But it's a water ring. The circulating mold shall prevail. Formulation and mixing granulation of extrusion molding materials for high impact polypropylene pipe
If the speed of the die mouth is not sufficient, 15 parts of polypropylene powder (melt flow rate 0.5-1g / 10min) with four original formulas (mass parts) will be produced, and the pressure capacity will be decreased (refer to the polyethylene e rate 1 / 10min of the reference example). The water temperature is too high,
15 parts of 2 (2 hydroxy 35 Di tert BUTYLPHENYL) - 5-chlorobenzotriazole (after UV tube shaping
A3 parts, 03 parts of antioxidant (124), 04 parts of carbon black and 0.5 parts of sodium benzoate. After that, 20 parts of styrene butadiene styrene copolymer (SBS), 15 parts of calcium carbonate (800 mesh), 0.5 parts of antioxidant (124), 703 parts of light stabilizer (UV tube applied to each), carbon black and other additives can be directly added to the polypropylene powder of reference example 2 (melt flow rate: 0.2-0.5g / 10min).
95 ℃, mixing granulation of Chang ② raw materials. The production process sequence of mixing granulation of raw materials is as follows. A corrosive Road, non-toxic, uniformly mixed metering tree and various auxiliary formulations are required to be mixed together after mixing and extruding the amount of particles by the extruder
The production method of mixing and granulation of scale and resistant raw materials after extrusion and melting with rubber strips is as follows. After measuring PP resin and other additives according to the formula requirements, add them into the kneader sample, knead and stir for more than 30min, and the raw materials are mixed evenly. After the material group is punctured, the machine stops heating. The forbidden village exovision · Kaishang is heated to (55 ± 5 ℃) to limit the exovision of Qianlong people by machine. The discharged material is cooled and then dewatered, air dried, and pulverized (Yang'an fanglang). First, calcium carbonate is heated in a mixer and mixed for in, which is beneficial to melt development and Co. then, PP and SBS are added to mix the auxiliary materials under the condition of 5). After mixing for 3-4 minutes, the auxiliary materials are mixed and stirred evenly. After the mixture is cooled to 40 degrees, people go out of the machine to mix and melt Effect of different SBS content on cohesive field of high impact polypropylene extruded pipe
See table 5-37 for the influence of blend properties.
The ratio (mass ratio) of PP / sbs100 is 5-37, and the influence of the same SBS content in PP tree on the energy of polypropylene blend is 95 / 590 / 1080 / 20
fifty thousand one hundred and fifty-four
Impact strength of falling ball / (kJ / m *)
259 389 583 7842 performance 22 ℃ - 28 ℃ Rockwell hardness (R) 98 81 95 81 87 108 648 71 7842 4.2 bending modulus / x10mpa 13.3 12.9 11.3 9.03
(2) Extrusion molding of high impact polypropylene pipe
① Equipment conditions: screw universal type outgoing machine. The screw diameter is selected by reference to 12. The screw structure is of constant distance and varying depth, with the length diameter ratio L / d > 20:1 and the compression ratio 3:1; The traction speed of auxiliary machine is within the range of 0.3 ~ 2m / min.
② Barrel process temperature: 140 ~ 160 ℃ in feeding section, 170 ~ 190 ℃ in plasticizing section
Homogenization section 190 ~ 210 ℃.
The molding die temperature is 190 ~ 210 ℃.
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