PVC is the abbreviation of (Polyvinylchlorid), the main component of which is polyvinyl chloride, and other components are added to enhance its heat resistance, toughness and ductility. The top layer of this surface film is paint, the main component in the middle is polyvinyl chloride, and the bottom layer is back-coated adhesive.
It is a popular and widely used synthetic material in the world today. Its global usage ranks second among various synthetic materials. According to statistics, in 1995 alone, the production of PVC in Europe was about 5 million tons, and its consumption was 5.3 million tons. In Germany, the production and consumption of PVC averaged 1.4 million tons.
PVC pipe (divided into PVC-U pipe, PVC-M pipe and PVC-O pipe) Rigid polyvinyl chloride pipe is made of polyvinyl chloride resin, stabilizer, lubricant, etc., and is extruded by hot pressing. It is the earliest plastic pipe to be developed and applied.
PVC-U pipes have strong corrosion resistance, are easy to bond, are cheap, and have a hard texture. However, due to the leakage of PVC-U monomers and additives, they are only suitable for water supply systems with a conveying temperature not exceeding 45°C. Plastic pipes are used for drainage, wastewater, chemicals, heating and cooling liquids, food, ultrapure liquids, mud, gas, compressed air, and vacuum system applications.
PVC-O pipes, Chinese name biaxially oriented polyvinyl chloride, are the latest evolution of PVC pipes. Pipes manufactured through a special orientation process will be axially stretched and radially stretched for PVC-U pipes produced by extrusion, so that the PVC long-chain molecules in the pipes are arranged regularly in biaxial directions, obtaining a new type of PVC pipe with high strength, high toughness, high impact resistance, and fatigue resistance.
Classification
PVC can be divided into soft PVC and hard PVC. Among them, hard PVC accounts for about 2/3 of the market, and soft PVC accounts for 1/3. Soft PVC is generally used for floors, ceilings and leather surfaces, but because soft PVC contains plasticizers (this is also the difference between soft PVC and hard PVC), its physical properties are poor (for example, water pipes need to withstand a certain amount of water pressure, so soft PVC is not suitable for use), so its scope of use is limited. Hard PVC does not contain plasticizers, so it is easy to shape and has good physical properties, so it has great development and application value. In the production process of polyvinyl chloride materials, several additives must be added, such as stabilizers, plasticizers, etc. If all environmentally friendly additives are used, then PVC pipes are also non-toxic, odorless and environmentally friendly products.
Production process
Production process Raw materials + additives preparation → mixing → conveying and feeding → forced feeding → conical twin-screw extruder → extrusion mold → sizing sleeve → spray vacuum shaping box → immersion cooling water tank → ink printer → crawler tractor → knife lifting cutting machine → pipe stacking rack → finished product inspection and packaging.
PVC is being produced and applied worldwide at a growth rate of 4%. PVC is growing particularly fast in Southeast Asia, thanks to the urgent need for infrastructure construction in Southeast Asian countries. Among the materials that can produce three-dimensional surface films.
Process conditions
Drying: Drying is usually not required.
Melting temperature: 185~205C.
Mold temperature: 20~50C.
Injection pressure: up to 1500bar Holding pressure: up to 1000bar Injection speed: To avoid material degradation, a corresponding injection speed is generally used.
Runners and gates: All conventional gates can be used. If processing smaller parts, it is best to use a pinpoint gate or a submerged gate; for thicker parts, it is best to use a fan gate. The minimum diameter of the pinpoint gate or submerged gate should be 1mm; the thickness of the fan gate cannot be less than 1mm.
Typical uses: water supply pipes, household pipes, house wall panels, commercial machine housings, electronic product packaging, medical equipment, food packaging, etc.
Material properties
ABS (Acrylonitrile-Butadiene-Styrene Copolymer)
ABS is used for conveying drinking water, slurries and chemicals. DWV (Drain Waste Vent) applications are most commonly used.
Unplasticized Polyvinyl Chloride (UPVC) and CPVC (Post-Chlorinated Polyvinyl Chloride)
UPVC has excellent chemical resistance throughout the entire operating temperature range and has a wide range of working pressure bands. Due to its long-term high strength characteristics, stiffness and cost-effectiveness, UPVC systems account for a considerable proportion of plastic pipe installations.
CPVC is resistant to a variety of acids, alkalis, salts, alkanes, halogens and alcohols. It is not resistant to solvents, aromatics and certain chlorinated hydrocarbons.
PP (Polypropylene)
Polypropylene is suitable for use in food, drinking water and ultra-pure waters, as well as in the pharmaceutical and chemical industries.
PE (Polyethylene)
Polyethylene has been successfully used for many years for the safe conveyance of drinking water and wastewater, hazardous waste, and compressed gases.
Pipe Advantages
1. It has good tensile and compressive strength: but its flexibility is not as good as other plastic pipes.
2. Low fluid resistance: The wall of PVC-U pipe is very smooth, with little resistance to fluid. Its roughness coefficient is only 0.009, and its water transport capacity can be increased by 20% compared with cast iron pipes of the same diameter and 40% compared with concrete pipes.
3. Excellent corrosion resistance and chemical resistance: PVC-U pipes have excellent acid resistance, alkali resistance, and corrosion resistance. They are not affected by moisture and soil pH, and no anti-corrosion treatment is required when laying pipes.
4. Good water tightness: The installation of PVC-U pipes, whether it is connected by bonding or rubber rings, has good water tightness.
5. Anti-bite: PVC-U pipes are not a source of nutrition, so they will not be eroded by rodents. According to the test conducted by the National Health Foundation in Michigan, mice will not bite PVC-U pipes.
6. Performance test: curing time, shrinkage, splitting strength, tensile properties, peel strength, thermal stability, applicable period, storage period, release of harmful substances.
Disadvantages of pipes
1. Not suitable for hot water pipes, can be used as domestic water supply pipes, but not as direct drinking water supply pipes.
2. Easy to crack when impacted.
3. Some low-quality counterfeit UPVC pipes have plasticizers added during production, which can cause medium pollution and greatly shorten the aging period of UPVC pipes.
Construction and maintenance
There are three main ways to connect PVC pipes: sealing rubber ring, bonding and flange connection. Pipes with a diameter greater than or equal to 100 mm generally use rubber ring interfaces; pipes with a diameter less than 100 mm generally use bonding joints, and some use flexible joints. When pipes cross sewers or other pipes, metal pipes are generally used. At this time, plastic pipes and metal pipes are connected by flanges. The connection between the valve and the pipe is also flanged.
1 When solvent bonding is used for small-diameter pipes, the socket must be rounded to form a bevel, and the fracture must be flat and vertical to the axis, so that it can be firmly bonded to avoid leakage.
2 Generally, PVC pipes with a diameter greater than or equal to 100 mm use rubber ring interfaces. Before installation, personnel must be arranged to chamfer the pipe socket and check whether the quality of the rubber ring is qualified. The socket, rubber ring, etc. must be wiped clean during installation.
3 The trench excavation for traditional pipeline installation only requires that the pipe can be placed in the trench and sealed. When the original soil layer is not loosened, there is no need to pressurize and compact the cushion layer.
4 Generally, PVC pipe branches can be split with a tee or a vertical water stop plug. During construction, a saddle-shaped accessory and half a two-in-one tee can be added and clamped with a U-shaped bolt, which thickens the pipe wall, and then holes are drilled directly on it, and then connected with external threaded plastic parts. The test shows that the pressure test acceptance after construction using this method can fully meet the requirements of the specification. In addition, thrust piers should be set at the locations where the water flow in the pipe generates thrust, such as elbows, tees, and pipe end sealing plates, to withstand the thrust of the water flow.
5 PVC pipe is a new type of non-metallic pipe. Its specific location cannot be detected by existing metal pipe detection equipment. However, this problem can be easily solved by burying an electric wire on the pipe during the pipeline burial construction.
Pipe installation structure
How to Choose PVC Pipe Suppliers
Selecting the right PVC pipe suppliers is crucial for ensuring the quality, reliability, and cost-effectiveness of your project. Here are some key factors to consider when evaluating potential suppliers:
1. Product Quality
Certification and Standards: Check if the supplier’s PVC pipes meet international and local quality standards, such as ISO or ASTM certifications.
Material Composition: Ensure the pipes are made from high-grade polyvinyl chloride without harmful additives. High-quality PVC water pipes should be durable, corrosion-resistant, and environmentally friendly.
Durability Tests: Ask about performance tests, including pressure resistance, thermal stability, and leakage prevention.
2. Supplier Reputation
Experience in the Industry: Opt for PVC pipe suppliers with a proven track record and expertise in manufacturing pipes for various applications.
Customer Reviews and Feedback: Research customer testimonials, ratings, and case studies. Positive reviews from satisfied clients can indicate reliability.
References: Request references from previous customers, especially for large-scale projects.
3. Range of Products
Ensure the supplier offers a diverse range of PVC pipes, such as PVC-U, PVC-M, and PVC-O pipes, to meet different project requirements.
Look for specialized products like PVC water pipes, drainage pipes, and pipes for chemical or industrial use.
Availability of fittings, connectors, and accessories to complement the pipes.
4. Pricing and Cost-Effectiveness
Request detailed quotes to compare prices among various PVC pipe suppliers.
Avoid suppliers with significantly lower prices, as this may indicate inferior quality.
Evaluate bulk purchasing discounts and long-term contract benefits.
5. Supply Chain Reliability
Delivery Times: Choose suppliers who can meet your project deadlines with consistent delivery schedules.
Inventory Management: Ensure the supplier maintains sufficient stock to prevent delays.
Global Reach: For international projects, prefer PVC pipe suppliers with established export capabilities.
6. Technical Support and Services
Customization: Some projects may require customized PVC water pipes. Ensure the supplier can accommodate specific dimensions or features.
After-Sales Support: Reliable PVC pipe suppliers should provide after-sales services, including troubleshooting and product maintenance.
Technical Expertise: Suppliers with knowledgeable staff can guide you in choosing the right products for your application.
7. Sustainability Practices
Opt for environmentally conscious suppliers who use eco-friendly additives and sustainable production processes.
Ensure the PVC pipes are non-toxic, odorless, and meet environmental safety regulations.
8. Logistics and Packaging
Check if the supplier provides secure and damage-free packaging for the PVC pipes.
Confirm their ability to handle complex logistics, especially for large orders or international shipments.
Choosing the right PVC pipe suppliers involves a combination of quality assurance, cost-effectiveness, and service reliability. By thoroughly evaluating these factors, you can ensure a successful partnership that supports your project's goals.
For customized PVC water pipes or industry-specific solutions, seek suppliers with a strong reputation and proven expertise in meeting diverse customer needs.
