Creative Mechanisms Staff on July 6, 2016
Polyvinyl Chloride (PVC) is one of the most commonly used thermoplastic polymers worldwide (next to only a few more widely used plastics like PET and P.P.). It is naturally white and very brittle (before the additions of plasticizers) plastic. PVC has been around longer than most plastics, first synthesized in 1872 and commercially produced by B.F. Goodrich Company in the 1920s. By comparison, many other common plastics were first synthesized and commercially viable only in the 1940s and 1950s. It is used most commonly in the construction industry and is also used for signs, healthcare applications, and fiber for clothing. PVC was accidentally discovered twice, once in 1832 by French chemist Henri Victor Regnault, and then rediscovered in 1872 by a German man named Eugene Baumann. Check out theindustry's best online coursefor new inventors. Lean on veteran guidance to help take your product from initial idea to profitable product. PVC is produced in two general forms: a rigid or unplasticized polymer (RPVC or uPVC), and the second as a flexible plastic. In its base form, PVC is characterized by its rigid yet brittle structure. While the plasticized version holds various uses across multiple industries, the rigid version of PVC also has its share of uses. Industries such as plumbing, sewage, and agriculture can utilize rigid PVC across many functions. Flexible, plasticized, or regular PVC is softer and more amenable to bending than uPVC due to the addition of plasticizers like phthalates (e.g., diisononyl phthalate or DINP). Flexible PVC is commonly used in construction as insulation on electrical wires or in flooring for homes, hospitals, schools, and other areas where a sterile environment is a priority. In some cases, PVC can act as an effective replacement for rubber. Rigid PVC is also used in construction as a pipe for plumbing and siding, commonly referred to by the term "vinyl" in the United States. PVC pipe is often referred to by its "schedule" (e.g., Schedule 40 or Schedule 80). Significant differences between the schedules include things like wall thickness, pressure rating, and color.
What is Polyvinyl Chloride (PVC), and What is it Used For?
The Base Forms and Functions of Polyvinyl Chloride (PVC)
Polyvinyl Chloride (PVC) is one of the most commonly used thermoplastic polymers worldwide (next to only a few more widely used plastics like PET and P.P.). It is naturally white and very brittle (before the additions of plasticizers) plastic. PVC has been around longer than most plastics, first synthesized in 1872 and commercially produced by B.F. Goodrich Company in the 1920s. By comparison, many other common plastics were first synthesized and commercially viable only in the 1940s and 1950s. It is used most commonly in the construction industry and is also used for signs, healthcare applications, and fiber for clothing. PVC was accidentally discovered twice, once in 1832 by French chemist Henri Victor Regnault, and then rediscovered in 1872 by a German man named Eugene Baumann.
Check out theindustry's best online coursefor new inventors. Lean on veteran guidance to help take your product from initial idea to profitable product.
PVC is produced in two general forms: a rigid or unplasticized polymer (RPVC or uPVC), and the second as a flexible plastic. In its base form, PVC is characterized by its rigid yet brittle structure. While the plasticized version holds various uses across multiple industries, the rigid version of PVC also has its share of uses. Industries such as plumbing, sewage, and agriculture can utilize rigid PVC across many functions.
Flexible, plasticized, or regular PVC is softer and more amenable to bending than uPVC due to the addition of plasticizers like phthalates (e.g., diisononyl phthalate or DINP). Flexible PVC is commonly used in construction as insulation on electrical wires or in flooring for homes, hospitals, schools, and other areas where a sterile environment is a priority. In some cases, PVC can act as an effective replacement for rubber. Rigid PVC is also used in construction as a pipe for plumbing and siding, commonly referred to by the term "vinyl" in the United States. PVC pipe is often referred to by its "schedule" (e.g., Schedule 40 or Schedule 80). Significant differences between the schedules include things like wall thickness, pressure rating, and color.
Some of PVC plastic's most important characteristics include its relatively low price, its resistance to environmental degradation (as well as to chemicals and alkalis), high hardness, and outstanding tensile strength for plastic in the case of rigid PVC. PVC remains widely available, commonly used, and easily recyclable (categorized by resin identification code "3").
What are the Characteristics of Polyvinyl Chloride (PVC)?
Some of the most significant properties of Polyvinyl Chloride (PVC) are:
- Density: PVC is very dense compared to most plastics (specific gravity around 1.4)
- Economics: PVC is readily available and cheap.
- Hardness: Rigid PVC ranks well for hardness and durability.
- Strength: Rigid PVC has excellent tensile strength.
Polyvinyl Chloride is a "thermoplastic" (as opposed to "thermoset") material, which has to do with the way the plastic responds to heat. Thermoplastic materials become liquid at their melting point (a range for PVC between the very low 100 degrees Celsius and higher values like 260 degrees Celsius depending on the additives). A primary useful attribute about thermoplastics is that they can be heated to their melting point, cooled, and reheated again without significant degradation. Instead of burning, thermoplastics like polypropylene liquefy allows them to be easily injection molded and then subsequently recycled. By contrast, thermoset plastics can only be heated once (typically during the injection molding process). The first heating causes thermoset materials to set (similar to a 2-part epoxy), resulting in a chemical change that cannot be reversed. If you tried to heat a thermoset plastic to a high temperature a second time, it would only burn. This characteristic makes thermoset materials poor candidates for recycling.
Why is Polyvinyl Chloride (PVC) used so often?
PVC offers a wide variety of applications and advantages across multiple industries in both its rigid and flexible forms. In particular, Rigid PVC possesses a high density for plastic, making it extremely hard and generally incredibly strong. It is also readily available and economical, which, combined with most plastics' long-lasting characteristics, makes it an easy choice for many industrial applications like construction.
PVC has an extremely durable nature and lightweight, making it an attractive material for construction, plumbing, and other industrial applications. Additionally, its high chlorine content makes the material fire-resistant, another reason why it has gained such popularity across various industries.
What Are The Different Types of PVC?
Polyvinyl Chloride is widely available in two broad categories: rigid and flexible. Each type comes with its own set of advantages and ideal uses for different industries. Flexible PVC can act as electrical cable insulation and a rubber alternative. Rigid PVC has various uses in construction and plumbing, providing a lightweight, cost-effective, and durable material to use.
How is PVC made?
Polyvinyl Chloride is made from one of three emulsion processes:
- Suspension polymerization
- Emulsion polymerization
- Bulk polymerization
Polyvinyl Chloride for Prototype Development on CNC Machines, 3D Printers, & Injection Molding Machines
Two main issues are working with PVC that makes it relatively problematic and not generally recommended for use by non-professionals. The first is the emission of toxic and corrosive gases when melting the material. This happens to some extent or another while 3D printing, CNC machining, and injection molding. We recommend taking a look at the MSDS data sheets for different chlorinated hydrocarbon gases like chlorobenzene and discussing the production process with a professional manufacturer. Second is the corrosive nature of PVC. This is problematic when PVC is repeatedly coming into contact with metal nozzles, cutters, or mold tools made from a material other than stainless steel or some other similarly corrosion-resistant metal.
Polyvinyl Chloride is available in filament form as a plastic welding rod (the material used for welding), but it is not presently retrofit for specific use in 3D printing. Although there are a growing number of plastics and plastic substitutes available for 3D printing, by far, the two most common are still ABS and PLA. At Creative Mechanisms, we typically 3D print with ABS. For a list of reasons why and compare the two most common 3D printing plastics (ABS and PLA) for 3D printing, read here.
The biggest issue with PVC for 3D printing is its corrosive nature (potentially compromising typical machines' functionality if it were used over a longer period). An interesting kickstarter developed a PVC capable 3D printing nozzle (extruder head) put forward by engineer and entrepreneur Ron Steele that unfortunately closed without enough interest in 2014. You can take a look at the introductory pitch (video) here:
Polyvinyl Chloride can be cut on a CNC machine, but any machinist who has tried has probably experienced degradation in the cutter depending on the material it is made. PVC is corrosive and abrasive, and cutters that are not made from stainless steel or a comparably corrosive resistant material are likely to deteriorate over time.
Polyvinyl Chloride can be injected just like other plastics, but chlorine in the material complicates the process. This is because melted PVC can give off a corrosive, toxic gas. Accordingly, shops need to be equipped with good ventilation systems. Those that aren't are likely to be hesitant to work with the material. Additionally, unique corrosive resistant materials like stainless steel or chrome plating are required for the mold tool when injection molding PVC plastic. Shrinkage in PVC tends to be between one and two percent. It can still vary based on several factors, including material durometer (hardness), gate size, holding pressure, holding time, melt temperature, mold wall thickness, mold temperature, and the percentage and type of additives.
Is PVC Toxic?
PVC can pose a health hazard when burned as it emits hydrogen chloride (HCl) fumes. In applications where the likelihood of fire is high, PVC free electrical wire insulation is sometimes preferred. Fumes can also be emitted when melting the material (such as during prototyping and manufacturing processes like 3D printing, CNC machining, and injection molding). We recommend taking a look at the Material Safety Data Sheets (MSDS) for different chlorinated hydrocarbon gases like chlorobenzene and discussing the production process with a professional manufacturer.
What are the Advantages of Polyvinyl Chloride?
PVC provides industries with a series of critical advantages that have cemented its place as one of the most popular and widely used plastics on the market. These advantages include:
- Polyvinyl Chloride is readily available and relatively inexpensive.
- Polyvinyl Chloride is very dense and thus very hard and resists impact deformation very well relative to other plastics.
- Polyvinyl Chloride has outstanding tensile strength.
- Polyvinyl Chloride is very resistant to chemicals and alkalis.
PVC's advantages helped solidify its place as one of the most used plastics around the world. However, even though it's widely effective and popular, you have to consider some factors when using the material.
What are the Disadvantages of Polyvinyl Chloride?
While PVC has a host of advantages that make it a desirable material to work with, there are some reasons to take caution. The disadvantages that you have to account for when using PVC include:
- Polyvinyl Chloride has very poor heat stability. For this reason, additives that stabilize the material at higher temperatures are typically added to the material during production.
- Polyvinyl Chloride emits toxic fumes when melted or subject to a fire.
Although there are some shortcomings, Polyvinyl Chloride is an excellent material overall. It has a unique blend of qualities that make it particularly useful for the construction business. By taking note and accounting for the shortcomings of the material, you can effectively navigate and compensate so you can effectively use the material in your upcoming projects.
What are the properties of Polyvinyl Chloride?
Polyvinyl Chloride (PVC)
212 - 500 °F (100 - 260°C) ***
Heat Deflection Temperature (HDT)
92 °C (198 °F) **
Flexible PVC: 6.9 - 25 MPa (1000 - 3625 PSI)
Rigid PVC: 34 - 62 MPa (4930 - 9000 PSI) **
1.35 - 1.45
*At standard state (at 25 °C (77 °F), 100 kPa)
PVC contains dangerous chemical additives including phthalates, lead, cadmium, and/or organotins, which can be toxic to your child's health. These toxic additives can leach out or evaporate into the air over time, posing unnecessary dangers to children.What do you know about PVC? ›
Polyvinyl Chloride (PVC or Vinyl) is a high strength thermoplastic material widely used in applications, such as pipes, medical devices, wire and cable insulation...the list is endless. It is the world's third-most widely produced synthetic plastic polymer.What is PVC plastic used for? ›
PVC is a versatile material that offers many possible applications, these include; window frames, drainage pipe, water service pipe, medical devices, blood storage bags, cable and wire insulation, resilient flooring, roofing membranes, stationary, automotive interiors and seat coverings, fashion and footwear, packaging ...What is special about PVC? ›
PVC has an extremely durable nature and lightweight, making it an attractive material for construction, plumbing, and other industrial applications. Additionally, its high chlorine content makes the material fire-resistant, another reason why it has gained such popularity across various industries.Is PVC safe for drinking water? ›
Plastic pipe such as PVC (polyvinyl chloride, used for cold water only), and CPVC (chlorinated polyvinyl chloride, used for both hot and cold water) have been around for years, and both are approved for use with drinking water.Is PVC cancerous? ›
Which cancers are associated with exposure to vinyl chloride? Vinyl chloride exposure is associated with an increased risk of a rare form of liver cancer (hepatic angiosarcoma), as well as primary liver cancer (hepatocellular carcinoma), brain and lung cancers, lymphoma, and leukemia.What causes PVC to fail? ›
The PCV valve can fail in one of two ways: it can either become stuck in the open position or become stuck in the closed position. These two problems tend to stem from very different causes. For example, a common reason that PCV valves become stuck in the closed position is because they are clogged.Is PVC flammable? ›
The myth that PVC is highly flammable is readily countered by the fact that chlorine contained in PVC actually acts as a fire retardant, which inhibits the spread of flames. Plus, when the source of flame is removed, PVC is self-extinguishing.Is PVC toxic to skin? ›
Totally. PVC in its manufactured form is safe to touch.Why is PVC rarely recycled? ›
PVC waste consists of different types of materials of diverse origins, which makes it difficult to recycle due to high quality demands for the recycled material. Separate collection is costly and there are no economies of scale.
What makes the new car or shower curtain smell? PVC is useless without the addition of many toxic additives, which can make the PVC product itself harmful to consumers. These chemicals can evaporate or leach out of PVC, posing health risks to children and consumers (off-gassing).Can PVC be recycled? ›
PVC can be recycled repeatedly up to 8 times depending on the application, because the recycling process does not measurably decrease the chain length of PVC molecules. The European industry has been working very hard to boost collection of PVC waste and to optimise recycling technologies.Is PVC toxic when heated? ›
One kilogram of PVC heated to 300 degrees C releases an estimated 12.9 g of hydrochloric acid (HCl) and 4.9 g of carbon monoxide (CO). We attributed the outbreak to exposure to toxic HCl and CO and rejected the hypothesis of mass psychogenic illness.What dissolves PVC? ›
[ABS, PVC, HIPS] => Acetone and Methyl Ethyl Ketone [MEK aka 2-Butanone] will dissolve both ABS and PVC and chemically rebuild the joint in a less ordered manner as the solvents dries.What are 4 properties of PVC? ›
PVC (plasticised) is less rigid; has high impact strength; is easier to extrude or mould; has lower temperature resistance; is less resistant to chemicals, and usually has lower ultimate tensile strength.Is PVC toxic for food? ›
Is that safe? Yes, PVC is a food-safe material for gardens and aquaponics.Why is PVC not good for hot water? ›
The short answer: No. Explanation: PVC is a thermoplastic, and therefore, at some point it will begin to degrade and break down as it's heated up. It just so happens that Schedule 40 PVC's maximum operating temperature is 140 degrees Fahrenheit, around the same temperature that hot water gets to in most homes.Does salt water damage PVC? ›
PVC is inherently resistant to salts, so the saline solution is not a problem. Yet, PVC is prone to permeation or leaching to high levels of organics, which may be present prior to filtration and desalination. CPVC. CPVC is also completely resistant to salts.Can bacteria grow on PVC? ›
Only the number of bacteria on the PVC surface was significantly lower (193 CFU cm−2) than on PEX. Significant differences in the number of heterotrophic bacteria growing at 22 °C were detected between all three plastics. The highest HPC at 22 °C, i.e. 1.22 × 105 cm−2 was found in biofilm from PVC.How long does PVC usually last? ›
As one of the most-used plumbing materials, PVC pipe is known for being very durable and long-lasting. In fact, PVC pipes last approximately 100 years. Of course, there are various factors that determine just how long specific PVC pipes will survive, including what it's exposed to and how it's installed.
Because PVC is immune to corrosion, a minimum service life of at least 100 years can be expected. This figure is supported by a number of independent studies, as well as the experience of many long-term users of PVC piping systems.Is PVC safe to breathe? ›
PVC is dangerous to human health and the environment throughout its entire life cycle, at the factory, in our homes, and in the trash. Our bodies are contaminated with the chemicals released during the PVC lifecycle, such as mercury, dioxins, and phthalates, which may pose irreversible life-long health threats.Is PVC toxic to adults? ›
Not directly. However, when it's burned, it releases harmful chemicals like dioxin, which is a carcinogen. These chemicals are harmful to human health.Is vinyl or PVC more toxic? ›
While the fact that vinyl contains carcinogens should be reason enough to avoid it, PVC is increasingly dangerous when burned. Therefore, house and building fires involving PVC are dangerous not only for homeowners and workers, but for firefighters and rescue workers as well.Is cutting PVC toxic? ›
PVC pipes present no inhalation, ingestion or contact hazards. Cutting and grinding PVC pipe will release nuisance dust particles which are non-toxic.What gases does PVC give off? ›
The major gaseous products of the combustion of PVC are carbon monoxide, carbon dioxide, hydrogen chloride and water.How does PVC affect the body? ›
Having frequent premature ventricular contractions (PVCs) or certain patterns of them might increase the risk of developing irregular heart rhythms (arrhythmias) or weakening of the heart muscle (cardiomyopathy).What does PVC smell like? ›
PVC shower curtains release toxic chemicals into the air.
“It smells sort of like gasoline.
Polyvinyl chloride (PVC) mains manufactured prior to 1977 contain elevated levels of vinyl chloride monomer, which are prone to leaching (Flournoy, 1999). Vinyl chloride is a toxic chemical with known carcinogenic effects; the drinking water MCL is 2 µg/L, enforceable at the point of entry to the distribution system.What happens when PVC is burned? ›
The dehydrochlorination reaction of burning PVC pipe at 200–300 °C is responsible for the release of hydrogen chloride.
Bisphenol A (BPA) used as an additive in polyvinyl chloride (PVC) products is an endocrine disrupter that causes negative effects on human health.Is PVC FDA approved? ›
Additionally, organizations like the U.S. Food and Drug Administration (FDA) and Consumer Product Safety Commission (CPSC) have confirmed that PVC is a safe product. PVC is approved for use around the world in water distribution and transmission, consumer products and medical applications.