PVC, UPVC, CPVC, PP, PE, PB, PVDF plastic pipe performance and differences

CPVC

The resin is made by chlorination-modified polyvinyl chloride (PVC) resin and is a new type of engineering plastic. It comes in the form of loose, white or light yellow granules or powder, which is odorless, tasteless, and non-toxic. Chlorination of PVC resin increases the irregularity of its molecular bonds and polarity, enhancing the resin's solubility and chemical stability, thereby improving the material's resistance to heat and corrosion from acids, alkalis, salts, and oxidants. It also improves mechanical properties, including the heat distortion temperature (HDT), by increasing the chlorine content from 56.7% to 63-69%, and the Vicat softening temperature from 72-82°C (to 90-125°C). The maximum operating temperature can reach 110°C, with a long-term operating temperature of 95°C. CORZAN CPVC offers superior performance indicators. Therefore, CPVC is a new engineering plastic with broad application prospects. UPVC

UPVC pipes, based on polyvinyl chloride resin, offer excellent properties such as accurate temperature sensing, timed melting, and rapid absorption of active additives while weakening the forces between resin molecular chains. Furthermore, they utilize a world-renowned calcium-zinc composite heat stabilizer, which captures, inhibits, and absorbs the release of hydrogen chloride during the resin's high-temperature and melting process. This stabilizer reacts with the polyolefin structure through double bonds, replacing reactive and unstable chlorine atoms within the molecule. This effectively and scientifically controls the resin's catalytic degradation and oxidative decomposition in the molten state.

PP

PP pipes are semi-crystalline materials. They are stronger than PE and have a higher melting point. Because homopolymer PP is very brittle above 0°C, many commercial PP materials are random copolymers with 1-4% ethylene or clamp copolymers with higher ethylene content. Copolymer PP materials have a lower heat distortion temperature (100°C), lower transparency, lower gloss, and lower rigidity, but possess greater impact strength. PP's strength increases with increasing ethylene content. PP has a Vicat softening temperature of 150°C. Due to its high crystallinity, this material exhibits excellent surface stiffness and scratch resistance. It is not susceptible to environmental stress cracking. PP is typically modified by adding glass fibers, metal additives, or thermoplastic rubbers. The flow rate (MFR) of PP ranges from 1 to 40. PP materials with lower MFRs exhibit better impact resistance but lower tensile strength. For materials of the same MFR, copolymers offer higher strength than homopolymers. Due to crystallization, PP exhibits a relatively high shrinkage, typically 1.8-2.5%. The directional uniformity of this shrinkage is much better than that of materials such as PE-HD. Adding 30% glass additives can reduce shrinkage to 0.7%. Both homopolymer and copolymer PP materials exhibit excellent resistance to moisture absorption, acid and alkali corrosion, and solvents. However, they lack resistance to aromatic solvents (such as benzene) and chlorinated hydrocarbons (carbon tetrachloride). PP also lacks the oxidation resistance of PE at high temperatures. Polypropylene (PP) is one of the lighter common plastics with excellent electrical properties, making it suitable for use as a moisture-resistant, heat-resistant, and high-frequency insulation material. PP is a crystalline polymer. Its large volumetric change and high molecular orientation during melt congealing result in significant shrinkage (1.0%-1.5%). In the molten state, increasing the temperature to reduce the viscosity of PP is ineffective. Therefore, during the molding process, increasing the injection pressure and shear rate should be prioritized to improve the quality of the finished product.

PE

Polyethylene, or PE, is the simplest macromolecular organic compound and the most widely used polymer material in the world. It is formed by the polymerization of ethylene and is classified by density into high-density polyethylene (HDPE), medium-density polyethylene (MDPE), and low-density polyethylene (LDPE). Low-density polyethylene is softer and is often polymerized at high pressures. High-density polyethylene, characterized by its rigidity, hardness, and mechanical strength, is often polymerized at low pressures. High-density polyethylene can be used in containers, pipes, and high-frequency electrical insulation, such as in radar and television. Low-density (HDPE) polyethylene is often used in large quantities. Polyethylene is waxy and has a smooth, waxy feel. When undyed, low-density polyethylene is transparent, while high-density polyethylene is opaque. Polyethylene is formed through the addition reaction and polymerization of ethylene (CH₂=CH₂), resulting in a high polymer chain consisting of repeating –CH₂– units. The properties of polyethylene depend on the polymerization method used. High-density polyethylene (HDPE) is produced by Ziegler-Natta polymerization under moderate pressure (15-30 atmospheres) catalyzed by organic compounds. Polyethylene molecules polymerized under these conditions are linear and have very long chains, with molecular weights reaching hundreds of thousands. Free radical polymerization under high pressure (100-300 MPa), high temperature (190–210°C), and peroxide catalysis produces low-density polyethylene (LDPE), which has a branched structure.

Polyethylene is insoluble in water and has very low water absorption. Even in some chemical solvents, such as toluene and acetic acid, it is only slightly soluble at temperatures above 70°C. However, microparticles of polyethylene can melt or solidify at temperatures between 15°C and 40°C. It melts at higher temperatures, absorbing heat; it solidifies at lower temperatures, releasing heat. Because it absorbs very little water, it resists moisture and has insulating properties, making it an excellent building material.

PB (polybutene) was developed and applied in the early 1970s. Its material properties dictate high technical and equipment requirements for producing profiles, resulting in significant fixed asset investment. Small-scale manufacturers generally lack the technical and financial resources to produce these materials.

PVDF (polyvinylidene fluoride)

It appears as a translucent or white powder or granule. Its molecular chains are tightly packed and have strong hydrogen bonds. It has an oxygen index of 46%, is non-flammable, has a crystallinity of 65% to 78%, and a density of 1.17 to 1.79 g/cm³. Its melting point is 172°C, its heat deflection temperature is 112 to 145°C, and its long-term operating temperature is -40 to 150°C.

PVDF resin primarily refers to vinylidene fluoride homopolymer or a copolymer of vinylidene fluoride with other small amounts of fluorinated vinyl monomers. PVDF resin combines the characteristics of both fluororesins and general-purpose resins. In addition to excellent chemical resistance, high temperature resistance, oxidation resistance, weathering resistance, and radiation resistance, it also possesses special properties such as piezoelectricity, dielectricity, and thermoelectricity. It is currently the second-largest fluoroplastic in terms of production volume, with a global annual production capacity exceeding 43,000 tons. PVDF applications are primarily concentrated in the petrochemical industry, electronics, and fluorocarbon coatings. Due to its excellent chemical resistance, processability, and fatigue and creep resistance, PVDF is an excellent material for pumps, valves, pipes, pipe fittings, storage tanks, and heat exchangers used in fluid handling systems or linings in petrochemical equipment. Its excellent chemical stability and electrical insulation properties enable the resulting equipment to meet TOCS and flame retardancy requirements, making it widely used in the semiconductor industry for the storage and transportation of high-purity chemicals. In recent years, porous membranes, gels, and separators made from PVDF resin have found application in lithium secondary batteries, a market segment currently experiencing one of the fastest-growing demand for PVDF. PVDF is one of the main raw materials for fluorocarbon coatings. Fluorocarbon coatings made with it have reached their sixth generation. Due to its exceptional weather resistance, PVDF resin can be used outdoors for long periods of time without maintenance. This type of coating is widely used in power plants, airports, highways, high-rise buildings, and other applications. PVDF resin can also be blended and modified with other resins. For example, PVDF and ABS resin can be blended to create composite materials, which are widely used in construction, automotive decoration, and appliance housings.

PVC is a type of plastic decorative material. PVC, short for polyvinyl chloride, is made from polyvinyl chloride resin as the main raw material, with appropriate amounts of anti-aging agents and modifiers added. The material is then processed through mixing, calendering, and vacuum forming.

PVC is lightweight, heat-insulating, thermally insulating, moisture-resistant, flame-retardant, and easy to apply. Available in a wide variety of sizes, colors, and patterns, it offers a highly decorative effect and can be used for interior walls and ceilings. It is one of the most widely used decorative plastics.

The advantages of PVC gussets are as follows: 1. Lightweight, heat-insulating, heat-insulating, moisture-proof, flame-retardant, acid- and alkali-resistant, and corrosion-resistant. 2. Good stability and dielectric properties, durable, anti-aging, easy to weld and bond. 3. Strong bending strength and impact toughness, and high elongation when broken. 4. It is very easy to process and shape through kneading, mixing, sheet drawing, pelletizing, extrusion or die-casting, and can meet the needs of various profile specifications. 5. Smooth surface, bright color, and highly decorative, with a wide range of decorative applications. 6. Simple construction process and relatively convenient installation. PE pipes are made of polyethylene material. PE pipes are suitable for concealed installation, while exposed materials are prone to aging. In addition to the advantages of general plastics such as light weight, good strength, corrosion resistance, no scaling, and long service life, PP-R pipes also have the following main features: (1) Non-toxic, hygienic, and a green building material. PP-R raw materials are polyolefins, whose molecules are composed of carbon and hydrogen elements, are non-toxic, and have excellent hygienic properties; (2) Heat-resistant, heat-insulating, and energy-saving products. The Vicat softening temperature of PP-R pipes is 131.3℃, the maximum operating temperature is 95℃, and the long-term (50 years) operating temperature can reach up to 70℃. The thermal conductivity of this product is 0.24W/m℃, which is only 1/200 of the thermal conductivity of steel pipes. It has excellent energy-saving and heat-insulating effects when used for hot water pipes; (3) Easy and reliable installation, using hot-melt homogeneous connection, a joint connection can be completed in a few seconds, and high-quality metal inserts are used for connection with metal pipes and water appliances, which is safe and reliable. PP-R hot and cold water pipes are used in building hot and cold water systems, including central heating systems;

Heating systems within buildings, including floor and siding heating and radiant heating systems;

Purified drinking water supply systems;

Central air conditioning systems;

Agricultural and garden irrigation systems;

Stormwater pipe networks;

Swimming pool pipe networks;

Solar energy system pipe networks;

PPR pipes are generally used for small diameter pipes and can be installed in both exposed and concealed locations.

PB pipes are made of a polybutylene polymer material and are currently widely used in developed countries such as Europe and the United States, replacing copper pipes as the preferred material for hot water supply piping.

PEX pipes are primarily made of HDPE, along with additives such as initiators, crosslinkers, and catalysts. Other modifiers may be added for special requirements. PEX pipe is manufactured using the world's most advanced one-step process (MONSOIL). Silane grafting is added to ordinary polyethylene raw materials, forming chemical covalent bonds between polymer macromolecules to replace the original van der Waals forces. This creates a three-dimensional cross-linked network structure of cross-linked polyethylene with a cross-linking degree of 60% to 89%, endowing it with excellent physical and chemical properties.

ABS is a terpolymer based on styrene-butadiene-acrylonitrile. It has high impact toughness, good mechanical strength, heat resistance, and oil resistance. PVC pipe is commonly used for household electrical wiring, and it should be standard fire-resistant PVC pipe. Some sewer re-installation also uses PVC pipe, while PPR is commonly used for water pipe renovation and is more suitable for water pipes.

The essential difference lies in the raw materials. PPR is a random copolymer of polypropylene and PVC is polyvinyl chloride. PVC can be used for both water supply and drainage, while PPR is primarily used for water supply (the cost of using it for drainage is too high). Actually, PVC isn't toxic. Medical IV tubing and plastic packaging are often made of PVC. Construction uses simply incorporate a modifier. Furthermore, PPR can be hot-melted, while PVC cannot.

PPR is made from a copolymer of polypropylene and PVC from polyvinyl chloride. While PPR has a higher production cost, it also offers superior hygiene standards and can handle hot water temperatures below 75°C. Its disadvantage is that it is more susceptible to deformation. PVC, on the other hand, is widely used for agricultural irrigation due to its lower production cost. Its disadvantage is that it can only handle cold water.

PE Pipes

Temperature Resistance

PE water supply pipes have a very low low-temperature brittleness temperature and can be used between -40°C and 60°C. Winter installation and construction will not cause pipe cracking.

Corrosion Resistance

Polyethylene is an inert material, resistant to a wide range of chemical media and does not require corrosion protection. Chemicals in the soil will not degrade the pipes, preventing rot, rust, or corrosion.

Flexibility

PE water pipe has an elongation at break exceeding 800%. Local vibrations will not cause vibration throughout the pipe, making it highly seismic-resistant. Polyethylene's flexibility allows it to be coiled, reducing the number of connecting fittings and allowing for bypassing obstacles during installation, reducing construction complexity.

Pressure Resistance

Due to HDPE's high crystallinity, its strength and hardness increase. Its tight welds withstand internal pressure, making it widely used in water supply and combustion pressure pipes.

Hygiene

It is hygienic and non-toxic, preventing bacterial growth within the pipe and causing secondary water pollution, thus completely eliminating the problem of pipes contaminating water sources. Flow capacity: The inner wall of the PE water supply pipe is smooth, with a small friction coefficient, small fluid resistance, small head loss, and no scaling, which reduces the pressure loss of the pipeline and the energy consumption of water transmission, and has obvious economic advantages.

Pipeline Safety

PE water pipes utilize hot-melt and electric-melt connections. The joint strength is higher than the pipe itself, effectively resisting the circumferential and axial forces generated by internal pressure. Its excellent sealing performance eliminates the risk of pipe leaks caused by joint distortion.