PVC, UPVC, CPVC, PP, PE, PB, and PVDF Plastic Pipe Performance and Differences

PVC

PVC (PolyVinylChloride) is generally available in 7 grades (SG1-SG7) according to its hardness and performance, with a density of about 1.4g/cm³. Below SG4, it is generally a soft product, which requires a large amount of plasticizer during molding, and is mainly used for making artificial leather, wire and cable insulation, seals, etc. Above SG5, it is a hard product, mainly used for making various pipes, such as drainage, electrical, post and telecommunications pipes and fittings, various plates, sheets and profiles, etc. Its shrinkage rate in molding is 0.6-1.5%, and it has good mechanical properties. PVC has a shrinkage rate of 0.6-1.5%, good mechanical properties, excellent electrical properties, self-extinguishing, strong acid and alkali resistance, good chemical stability, low price, and is a very widely used general-purpose plastic. However, its development is hindered by its low use temperature, which is around 80℃ at the highest.

CPVC

Resin is made by chlorination modification of polyvinyl chloride (PVC) resin, which is a new type of engineering plastic. The product is white or light yellow tasteless, odorless, non-toxic loose granules or powder. after chlorination of PVC resin, the irregularity of molecular bonds increases and polarity increases, which increases the solubility of the resin and chemical stability, thus improving the material's heat resistance, corrosion resistance to acids, alkalis, salts, oxidizers, etc. Improved the mechanical properties of the value of the heat deflection temperature, chlorine content from 56.7% to 63-69%, Vicat softening temperature from 72-82 ℃, (increased to 90-125 ℃), the highest use temperature up to 110 ℃, long-term use temperature of 95 ℃. Among them, CORZANCPVC performance indicators are more excellent. Therefore, CPVC is a new type of engineering plastics with broad application prospects.

UPVC

UPVC pipe is made of polyvinyl chloride resin, which has excellent characteristics such as accurate temperature sensing, timing melting and rapid absorption of active ingredients of additives when the gravitational force between resin molecule chains is weakened, and at the same time, it adopts world famous calcium and zinc compound heat stabilizer, which can capture, inhibit and absorb the neutralization of hydrogen chloride in the process of resin being subjected to high temperature and melting, and carry out double bond addition reaction with polyene structure to replace the active and unstable chlorine atoms in the molecule. It can replace the reactive and unstable chlorine atoms in the molecule. Thus, the catalytic degradation and oxidative decomposition of the resin in the molten state can be controlled effectively and scientifically.

PP

PP pipe is a semi-crystalline material. It is harder and has a higher melting point than PE. Since homopolymer type PP is very brittle at temperatures above 0°C, many commercial PP materials are irregular copolymers with 1-4% ethylene or higher rates of ethylene content in a pincer-type copolymer. The strength of PP increases with the increase of ethylene content, and the Vicat softening temperature of PP is 150°C. Due to its high crystallinity, this material has good surface stiffness and scratch resistance. PP does not suffer from environmental stress cracking. Usually, PP is modified by adding glass fibers, metal additives or thermoplastic rubber. the flow rate MFR of PP ranges from 1 to 40. low MFR PP materials have better impact resistance but lower ductile strength. For the same MFR, the strength of copolymer type is higher than that of homopolymer type. Due to crystallization, the shrinkage of PP is quite high, generally 1.8~2.5%. And the directional uniformity of shrinkage is much better than that of materials such as PE-HD. The addition of 30% glass additive can reduce the shrinkage to 0.7%. Both homopolymer-type and copolymer-type PP materials have excellent resistance to moisture absorption, acid and alkali corrosion, and solubility. However, it has no resistance to aromatic hydrocarbon (such as benzene) solvents, chlorinated hydrocarbon (carbon tetrachloride) solvents, etc. PP also does not have oxidation resistance even at high temperatures like PE.

Polypropylene (PP) is one of the lighter common plastics, its electrical properties are excellent and can be used as humidity and heat resistant high-frequency insulation materials. PP is a crystalline polymer, the melt condensation due to large changes in specific volume, high degree of molecular orientation and presents a large shrinkage rate (1.0-1.5%). Therefore, during the molding process, injection pressure and shear rate should be increased to improve the molding quality of the product.

PE

It is the most widely used polymer material in the world today. It is polymerized from ethylene and is divided into high density polyethylene, medium density polyethylene and low density polyethylene according to the density. Low-density polyethylene is soft, more high-pressure polymerization; high-density polyethylene has the characteristics of rigidity, hardness and mechanical strength, more low-pressure polymerization. High-density polyethylene can do containers, pipes, but also high-frequency electrical insulation materials, used in radar and television. A large number of low-density (high-pressure) polyethylene is often used. Polyethylene is waxy and has a wax-like smoothness. When it is not dyed, low-density polyethylene is transparent, while high-density polyethylene is opaque. Polyethylene is a highly polymerized chain connected by repeated -CH2-units through the addition and polymerization of ethylene (CH2=CH2). The properties of polyethylene depend on the way it is polymerized; high density polyethylene (HDPE) is produced by Ziegler-Natta polymerization under moderate pressure (15-30 atm) catalytic conditions of organic compounds. Polyethylene molecules polymerized under such conditions are linear and have long molecular chains with molecular weights of several hundred thousand. In case of free radical polymerization under high pressure (100-300 MPa), high temperature (190-210C) and peroxide catalysis, low density polyethylene (LDPE) is produced, which has a branched structure.

Polyethylene is insoluble in water and has very little water absorption. It is only slightly soluble in some chemical solvents, such as toluene and acetic acid, at temperatures above 70°C. However, polyethylene in the form of particles can be melted or solidified between 15℃ and 40℃ with the change of temperature, melting when the temperature rises and absorbing heat; solidifying when the temperature decreases and releasing heat. It is also a good building material because it absorbs very little water, is not easily moistened, and has insulating properties.

PB

Polybutylene was developed and applied in the early 1970s, its material characteristics determine the high technical and equipment requirements for the production of profiles, and the fixed asset investment is large, the general small-scale manufacturers do not have the technical conditions and financial ability to produce.

PVDF

Appearance is translucent or white powder or particles, molecular chain arrangement is tight, and strong hydrogen bonding, oxygen index is 46%, non-combustible, crystallinity 65% ~ 78%, density of 1.17 ~ 1.79g/cm3, melting point of 172 ℃, heat deflection temperature 112 ~ 145 ℃, long-term use temperature of -40 ℃ ~ 150 ℃.

PVDF resin mainly refers to the homopolymer of vinylidene fluoride or vinylidene fluoride and a small amount of other fluorine vinyl monomer copolymer, PVDF resin both fluorine resin and general-purpose resin characteristics, in addition to good chemical resistance, high temperature resistance, oxidation resistance, weather resistance, radiation resistance, but also has piezoelectricity, dielectricity, thermoelectricity and other special properties, is the current production of fluorine containing plastics ranked PVDF applications are mainly concentrated in the petrochemical, electrical and electronic and fluorocarbon coatings three major fields, due to PVDF good chemical resistance, processability and fatigue and creep resistance, is one of the best materials for petrochemical equipment fluid handling system as a whole or lining pumps, valves, pipes, pipeline fittings, storage tanks and heat exchangers. Its good chemical stability, electrical insulation properties, so that the equipment made to meet the TOCS and flame retardant requirements, is widely used in the semiconductor industry on the storage and transport of high-purity chemicals, in recent years the use of PVDF resin made porous membrane, gel, diaphragm, etc., in the lithium secondary battery applications, the current use of PVDF has become one of the fastest growing market demand. PVDF is the most important fluorocarbon coating One of the raw materials, fluorocarbon coatings prepared from it has been developed to the sixth generation, because PVDF resin has super weather resistance, can be used outdoors for a long time without maintenance, this type of coating is widely used in power stations, airports, highways, high-rise buildings, etc. In addition, PVDF resin can also be blended with other resins to modify, such as PVDF and ABS resin blended to get composite materials, has been widely used in construction, automotive decoration, home appliances shell, etc.

PVC material is a kind of plastic decoration material, PVC is the abbreviation of polyvinyl chloride material, which is made of polyvinyl chloride resin as the main raw material, adding appropriate amount of anti-aging agent, modifier, etc., through the process of mixing, calendering, vacuum blistering and so on.

PVC material has the characteristics of light weight, heat insulation, heat preservation, moisture-proof, flame retardant, easy construction, etc. Specification, color and pattern

It is one of the most widely used decorative materials among plastic materials, and can be used in the decoration of interior walls and ceiling.

The advantages of PVC buckle board are mainly as follows

• Light weight, heat insulation, heat preservation, moisture proof, flame retardant, acid and alkali resistant, corrosion resistant.

• Stability, good dielectricity, durable, anti-aging, easy to fuse and bond.

• Strong bending strength and impact toughness, high elongation when ruptured.

• It is extremely easy to be processed and shaped by kneading, mixing, sheet drawing, granulation, extrusion or die-casting, and can meet the needs of various profile specifications.

• The surface is smooth, brightly colored and highly decorative, and the decorative application is wide.

• The construction process is simple and the installation is more convenient.

PE pipe is made of polyethylene material, PE pipe is suitable for concealed installation, and the material of open installation is easy to be aged.

PP-R pipe in addition to the general plastic light weight, good strength, corrosion resistance, non-scaling, long service life and other advantages, but also has the following main features:

• PP-R raw materials are polyolefin, whose molecules are composed of carbon and hydrogen elements, which are non-toxic and have excellent health performance;

• PP-R pipe has a Vicat softening temperature of 131.3℃, a maximum operating temperature of 95℃, and a long-term (50 years) operating temperature of 70℃. The thermal conductivity of the product is 0.24W/m℃, which is only 1/200 of the thermal conductivity of steel pipe, so it has excellent energy-saving effect for hot water pipe insulation;

• Easy installation, reliable, using hot fusion homogeneous connection, a few seconds to complete a joint connection, and metal pipe and water appliance connection using high-quality metal insert fittings, safe and reliable.

Application areas of PP-R hot and cold water pipes

• Hot and cold water systems in buildings, including central heating systems;

• Heating systems in buildings, including floor, wall panel heating and radiant heating systems;

• Purified water supply systems that can be used for direct drinking;

• Central (centralized) air conditioning systems;

• Agricultural, garden irrigation systems;

• Rainwater networks;

• Swimming pool networks;

• Pipe networks for solar facilities;

• PPR is generally used for small pipe diameters, and PPR is available for both open and dark installations.

PB pipe is polybutylene polymer material, currently in Europe and the United States and other developed countries, PB pipe has been widely used, and replaced the copper pipe as the preferred material for hot water supply pipeline.

The main raw material of PEX pipe is HDPE, as well as initiator, cross-linking agent, catalyst and other additives, and other modifiers can be added if there are special requirements.

PEX pipe is manufactured by the world's advanced one-step (MONSOIL method) technology, using ordinary polyethylene raw materials to add silane grafting material, forming chemical covalent bonds between polymer macromolecule chains to replace the original van der Waals forces, thus forming a three-dimensional cross-linked network structure of cross-linked polyethylene, the degree of cross-linking up to 60% ~ 89%, so that it has excellent physical and chemical properties.

ABS is a styrene-butadiene-acrylonitrile-based terpolymer, with high impact toughness and good mechanical strength, heat resistance, oil resistance, etc.

Home laying of electrical wiring using PVC pipe, and should be the standard fire PVC pipe, but also some re-laying of sewerage using PVC pipe, and commonly used PPR are used in the renovation of water lines, PPR is more suitable for water.

The essence of the difference is the raw material is different, ppr is random copolymer polypropylene, pvc is polyvinyl chloride. pvc drainage can be used, ppr is mainly for water (used as drainage cost is too high). In fact, pvc is not said to be toxic medical infusion tubes and plastic packaging are many pvc, used as a building is only the addition of improvers, plus ppr can be hot melt pvc can not.

PPR is copolymer polypropylene material production, PVC is produced from polyvinyl chloride material, the former high production costs, health grade is also better than PVC, and can go below 75 ℃ hot water, the disadvantage is easier to deformation. pvc is due to low production costs, is widely used in agricultural irrigation, the disadvantage is only go cool water.

PE pipe

• Temperature resistance

PE water supply pipe low temperature embrittlement temperature is very low, can be used in the range of -40 ℃ to 60 ℃, winter installation and construction will not occur in the pipe brittle crack.

• Corrosion resistance

Polyethylene is an inert material, resistant to a variety of chemical media erosion, no anti-corrosion protection, chemical substances in the soil will not cause any degradation of the pipe, will not occur rot, rust and corrosion phenomenon.

• Flexibility

The elongation at break of PE water supply pipe is more than 800%, and the local vibration will not cause the whole pipe to vibrate, so it has strong anti-seismic property. The winding nature of polyethylene makes PE water supply pipe can be coiled, reducing a large number of connecting fittings, which can bypass obstacles in construction and reduce the difficulty of construction.

• Pressure resistance

Due to the high crystallinity of HDPE, the strength and hardness increase. Fused tightly, it can withstand internal pressure and is commonly used for water supply and burning pressure pipes.

• Sanitary

Sanitary and non-toxic, no bacteria breeding in the pipe, will not cause secondary pollution of water quality, completely solve the defects of the pipeline pollution of water.

• Circulation ability

PE water supply pipe smooth inner wall, small friction coefficient, small fluid resistance, small head loss, no scaling, reduce the pressure loss of pipeline and water transmission energy consumption, the economic advantage is obvious.

• Pipeline safety

PE water supply pipe adopts hot fusion connection and electric fusion connection, the strength of the interface is higher than the strength of the pipe body, which can effectively resist the circumferential force and axial force generated by internal pressure. The sealing performance is good, so you don't have to worry about the pipeline leakage caused by the distortion of the interface.