PVC: What is it, How is it Made, and What is it Used For?
Ever seen the letters “PVC” as a material and wondered what that even is? Or read “polyvinyl chloride” and get a little suspicious it might be toxic?
Well, wonder no longer – we’ve got the answers for you! In this deep dive on polyvinyl chloride (AKA PVC) we’ll go over:
- What it is
- How it’s made
- Its characteristics
After we’ve covered the essentials, we’ll also answer some of the most common questions people ask about PVC.
Ready? Let’s go!
What is polyvinyl chloride (PVC)?
PVC is a synthetic polymer initially made by a happy accident in 1872. German scientist Eugene Baumann exposed vinyl chloride gas to sunlight. The result? A white solid powder dubbed PVC.
Today, PVC is the third most manufactured synthetic plastic polymer. It’s widely used because it's low-cost and versatile.
PVC is used in a variety of industries such as construction, electronics, clothing, and most importantly (in our completely unbiased opinion) — to make one of our favorite rug pads, the Anchor Grip rug pad.
Many people think that PVC is a thermosetting plastic, but it’s actually a thermoplastic. What does that mean?
When heated, thermoplastics can be remodeled without causing chemical change.
On the other hand, thermosetting plastics such as silicone can be heated but when they take a certain form, they’re set for good.
How is PVC made?
We could go through the super scientific jargon of how PVC is made, but this isn’t the type of science class where your eyes glaze over and you start daydreaming about lunch so we’ll try to keep it fun.
Basically, manufacturing PVC happens in three stages.
First, we combine chlorine (from sea salt) and ethylene (from natural gas or oils) to form ethylene dichloride. Second, we heat the s*** out of that compound in an environment with no oxygen.
This heating is called pyrolysis and it forms the vinyl chloride monomer.
Poly means many, so we essentially smush a bunch of the vinyl chloride monomers together with a process called polymerization to form a polyvinyl chloride polymer (PVC).
Key properties and characteristics of PVC
PVC possesses unique properties that make it suitable for many uses.
The properties of PVC include:
- High density: The density of PVC is 1.38 g/cm3.
- Low cost: Economically friendly and affordable.
- Good durability: PVC can last up to 40 years.
- High strength: High tensile strength (2.6 N/mm2) meaning it takes a lot of force to stretch it out and break it.
- Excellent electric insulator: PVC doesn't conduct electricity, making it great for electrical insulation.
- Fire-retardant: When PVC catches fire, it slowly extinguishes the fire because it contains chlorine and low oxygen content which combined, isn’t good for fire.
Now, let’s explore its benefits.
Benefits of PVC plastic
Lauded for its versatility, there are a lot of good things to say about PVC. These are some of the main ones.
Relatively inexpensive and widely available
With a solid cost to performance ratio, PVC is a great choice economically. In piping, PVC is often chosen over more expensive materials like copper because it does an equally good job for a fraction of the cost.
It’s also easily available and widely produced because it’s so inexpensive to manufacture.
PVC is lightweight but long-lasting. The average PVC pipe can last about 35 years.
It’s resistant to shock, corrosion, and weather aging. It’s very lightweight, making for excellent use in construction, packaging, and cabling.
High tensile strength
Tensile strength is the ability to stay intact when being pulled in opposite directions.
Because of the strong bonds found in the chemical structure of PVC, it doesn’t break easily. The breakage rate of PVC pipe is significantly lower than cast-iron.
PVC functions as an excellent insulator, and it doesn’t conduct electricity, making it good for wiring and manufacturing construction materials.
As a fire retardant, PVC can stop the intensity and spread of fires. Why? Because it has a combination of chlorine without much oxygen.
Limited Oxygen Index (LOI) measures the minimum percentage of oxygen in the atmosphere that supports the burning of a material.
If the material has an LOI above 21%, it’s less likely to sustain a fire. PVC’s LOI is above 27% – less likely to sustain a fire.
Because of PVC’s structure, it doesn’t chemically react with many substances. PVC rarely corrodes or otherwise reacts when it comes into contact with other chemicals and substances such as oils, inorganic acids, fats, salts, bases, and alcohols.
Think of it as the sloth of plastics.
This makes it ideal for a wide range of uses such as transporting several reagents through pipes — it doesn’t interact with any of the substances flowing through.
Disadvantages of PVC
Not all that glitters is gold, and PVC is no exception. There are some downsides to the use of this material, which include:
PVC is non-biodegradable, making it an environmental pollutant. It induces land pollution because plastic does not disintegrate. It causes air pollution because when it’s burned, it emits dioxin and hydrogen chloride — highly toxic chemicals to the environment.
Note: Thankfully, at RugPadUSA, we make our PVC rug pads like the Anchor Grip using soybean and bio-based fillers. This is to avoid using plasticizers like phthalates.
Health and safety concerns
Because of the toxic chemicals released by PVC during its manufacturing process, use, and disposal, it can be a threat to human health.
Toxins like phthalates and dioxins cause myriad illnesses such as hormonal imbalances, respiratory health effects, and in extreme cases, cancer.
PVC has low thermal stability, making it heat sensitive. When subjected to consistently high levels of heat, it degenerates. (Which is why we don’t recommend our Anchor Grip pad for radiant heat flooring.)
Manufacturers can improve its heat stability by introducing certain stabilizers like lead, cadmium, and zinc. These additives prevent the degradation of PVC when exposed to heat.
What is PVC used for?
PVC’s versatility makes it common in the production of many items ranging from rug pads to toys and even in piping and construction. Here’s a quick run-down of some PVC products.
Non-slip rug pads
Rugs on slick surfaces are all fun and games — until someone slips.
PVC non-slip rug pads are the best remedy to this problem. RugPadUSA’s PVC rug pads are top-notch, free of phthalates, and dense enough to resist compression. This means that when you walk on them, they don’t flatten but rather conform to your feet and provide cushion for years.
PVC usually gets a bad rap for staining floors, sticking to them, and stripping them of their luster. Our rug pads are different. They’re made in the USA with full control over production and engineered to maintain the integrity of your flooring.
PVC is favored in construction and used in roofing membranes, making siding, window frames, and wall coverings. It has steadily been replacing other building materials like wood, concrete, and clay in many applications.
Because PVC is:
- Easy to install
- Light weight
- Inert / Non-reactive to many chemicals
Basically, it’s spot on the money for construction.
Wiring and cables
PVC is an electrical insulator, making it good for use in wires and cables. Wires cannot be exposed because they’re made from materials that conduct electricity (such as copper). For example, if you were charging your phone with an exposed metal cable and you touched the cable, you’d likely get a harsh shock (literally).
Cable jackets made of PVC protect electrical wires and are strong enough to withstand temperature changes and dampness for more than 30 years.
Thanks to PVC’s durability and chemical resistance, PVC pipes don’t leak and are resistant to corrosion and weathering. You’ll see PVC pipes for everything from sewage lines and water mains to irrigation and even furniture.
Also, these pipes are unlikely to break because of the material’s high tensile strength.
You’ll find PVC packaging on everything from medicines to pillows because it’s flexible and easy to mold. The bottles that hold your pills? Probably made from PVC. The cling film you use to seal food? Also PVC.
In healthcare, PVC is a lifesaver (literally). It’s used to make IV bags, oxygen and dialysis tubes, blood bags, disposable sample containers, and many other tools that have become essential in medicine.
Along with flexibility and durability, PVC products have been a great support for healthcare because they can be sterilized using steam and then reused.
PVC is used for flooring in tile, sheet, or plank form and it’s not hard to see why! Water resistant, easy to clean, durable, soft to walk on… you get the picture. You may know PVC flooring better as vinyl, but these are one and the same.
Thanks to PVC’s durability, this flooring can last for 30 years or more.
FAQs about polyvinyl chloride
How many types of PVC are there?
There are two basic forms of PVC: rigid and flexible.
The rigid form is used in roofing, window frames, doors, and bank cards.
Flexible PVC has plasticizers like phthalates added to make it more flexible. It’s used in plumbing for pipes, cable insulation, roofing, and inflatable items.
Is it safe to touch PVC?
Totally. PVC in its manufactured form is safe to touch. This is the reason it’s used in hospitals for IV bags and tubing.
PVC is biocompatible, meaning it goes well with living cells found in body tissue.
Is PVC safe to hold drinking water?
Yes. Most PVC pipes are made to certain standards such as the ASTM D1785 Standard Specification for Polyvinyl Chloride (PVC) Plastic Pipes. These pipes are rigorously tested to ensure they’re not harmful to drinking water.
However, when you first get PVC pipes installed, you can taste some ‘plastic’ in the water. That has not been documented to be harmful, and the ‘plastic’ taste disappears after a while.
In some cases, high temperatures, high water pressure, and exposure to UV light can degrade the quality of PVC pipes and make the water unsafe to drink.
Can PVC cause cancer?
Not directly. However, when it’s burned, it releases harmful chemicals like dioxin, which is a carcinogen. These chemicals are harmful to human health.
Also, factory workers who make polyvinyl chloride are at risk of getting cancer through inhalation of the chemicals.
Is PVC banned in Europe?
No. PVC is not banned in Europe. However, the EU Commission is considering a bill to ban all plastic packaging, due to plastic’s negative environmental effects and threats to human health.
What can I use instead of PVC?
PVC can be substituted by substances like glass, ceramics, cast iron, rubber, and silicon. The choice is often based on opting for more environmentally friendly materials.
Is PVC eco-friendly?
We won’t lie to you – it’s not the most eco friendly of materials. During its production, use, and disposal, PVC can prove to be a menace to the environment. It is non-biodegradable, lasting in the environment for up to 40 years.
Chemicals like dioxins and phthalates are released during the life cycle of PVC. These can be harmful to all aspects of the environment — air, water, land, and living creates.
That being said, there are ways to make it more eco friendly such as using natural oils rather than coal, not using harmful additives like phthalates, and recycling the material rather than throwing it away.
How is PVC disposed of?
PVC is disposed of by incineration, recycling, or burying. The most practical and eco friendly way to dispose of PVC is through recycling.
Recycling can be done through sorting by hand, or these days, using machines. The recycled PVC retains its original composition. This process is known as mechanical recycling.
Another way of recycling PVC is through decomposition using heat and recycling the remains into other products. This is called feedstock recycling.
Does heating PVC weaken it?
Yes, it does. When you heat PVC or expose it to high temperatures, it will start to degrade because it has low heat stability. When it’s exposed to temperatures above 212 degrees Fahrenheit, it begins to lose its strong structure.
To maintain PVC’s integrity and promote longevity try to keep PVC in areas with moderate temperatures.
Does PVC get brittle with age?
Yes. As its life cycle progresses, PVC becomes weaker and more prone to breakage. This is mainly a result of chemical decomposition over time.
PVC also gets brittle when exposed to cold temperatures because its molecular bonds weaken. Extreme external stresses such as bending and lack of support also lead to breakage.
Is PVC clothing safe to wear?
Yes. PVC and other plastics have long been used in the manufacturing process of some clothing items such as raincoats, skirts, pants, and jackets.
Is PVC smell toxic?
No. The normal PVC smell is not toxic. However, when it’s burned, it does release toxic chemicals.
Can I put PVC in my recycling bin?
You can, but it’s wise to check with your local recycling department first. PVC is a very difficult material to recycle and it contaminates already recycled plastics because of its unique chemical components.
However, some recycling plants take in PVC waste to make it into something new.
Other materials used in rug pads
As great as PVC rug pads are, PVC is not the only material we use to make our high-quality products. We also use:
Felt is a mix of different fibers that can be compressed or matted into one fabric. The blend can consist of organic fibers like cotton or synthetic fibers like nylon.
Felt fabric makes for a great rug pad because of its density and the comfort it provides. It also protects floors from dents and scratches from heavy furniture.
Natural rubber generally outperforms synthetic non-slip rug pad materials in gripping capacity, breathability, and safety for the floor.
Our natural rubber rug pads are durable, sustainable, and eco-friendly. They grip your floors without having to stick on them, holding the rug in place.
We’ve reached the end of our little diving trip through PVC
Wouldn’t it be great to get a little souvenir to remember the trip?
If you’re considering a PVC rug pad for your rug, check out our Anchor Grip rug pad. Then, you can be the life of the party providing all these fun facts about the material your rug pad is made of! ;)
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