Is Polyester Waterproof?

Polyester is a widely used, prevalent material across an extensive list of everyday products. Items like clothing and jackets frequently use this material because it’s flexible, strong, and long-lasting.

Of course, the burning question on your mind right now would be: is polyester waterproof?

Our team is here to break down the what, why, and how of polyester fabric. For a quick answer, jump down to our verdict below. Let’s get started.

Common Uses of Polyester

It’s certainly no secret that polyester is a standard fabric. In fact, it’s likely used to make many items within your home – and possibly even within your reach at this moment. But even if it’s sitting right next to you (or on you), you may not realize it.

Clothing

Perhaps one of the most common uses of polyester is to make clothing. As we already mentioned, polyester is a reliable and durable material, so it makes sense that high-quality clothing would take advantage of that.

Polyester is also a material that you can mold and shape, and even combine with other materials. For example, manufacturers of the fabric often combined polyester fibers with natural fibers in the clothing. You can also find this material in the form of yarns and threads.

Some everyday clothing products you probably own that use polyester are:

  • Shirts
  • Jackets
  • Pants
  • Hats

Another plus for using polyester in clothing is that it is far more resistant to wrinkles than other common fabrics such as cotton. In most instances, this material also fades less, lasts longer, and resists staining. For that reason, many uniforms in various industries use polyester material.

Home Furnishing

Many fabrics in your own home also use polyester somewhere in their makeup. For the same reason as used in clothing, polyester is excellent for home items due to its resistance to staining, durability, and resistance to fading.

Some everyday items throughout your home that probably have some polyester in them include:

  • Bedsheets
  • Curtains
  • Blankets
  • Pillowcases
  • Upholstered furniture
  • Cushioning materials
  • Tablecloths

Many of the above list items greatly benefit from the fabric’s ability to fight off stains. Tablecloths, for example, are products that come into contact with a lot of different foods and liquids. A polyester tablecloth may last much longer than another type of fabric in this area.

One interesting use for polyester in the home that’s worth noting is finishes for wood products. This versatile material is known for its thinning properties and therefore is used in many spray-based applications for open-grain woods. The spray’s polyester component allows it to fill in wood grains, which builds thickness and durability.

Outdoor Accessories

Due to its resistance to stretching, ripping, and fading, polyester also makes a great addition to outdoor products. In addition to the traits we’ve already talked about, this super fabric is also great at combating mold and rot.

You can find polyester on the label of many of these outdoor products:

  • Fish Netting
  • Rope/Cords
  • Tents
  • Backpacks
  • Vehicle Upholstery
  • Sails

If you search through your camping equipment, you’re bound to find something that uses polyester, one way or another.

Other Products

Aside from the common and more obvious products we have already identified, polyester is also used in miscellaneous products that you might not immediately recognize:

  • Bottles
  • Liquid Crystal Displays (LCDs)
  • Dielectric Films
  • Tape and Wire Insulation
  • Air Filters
  • Pianos
  • Phone Cases

We could go on and on about polyester uses, but let’s get down to the nitty-gritty of this diverse material.

Technical Makeup of Polyester

Polyester fibers fall into the category of synthetic polymeric fiber and are the most common of the group. Its unique properties can be attributed to the inclusion of aliphatic and aromatic parts within its macromolecular chains and structure.

The base of the makeup of polyester is ethylene terephthalate, or PET, which is the direct product of ethylene diglycol and terephthalic acid. It is used because it delivers high-quality end-use properties, and it is easy to physically and chemically modify.

In fact, when working with PET, experts can manipulate it to suppress negative properties and enhance the positive ones. These changes occur when PET is conducted using stress, temperature, time, and environmental factors.

How it’s Made

Polyester is a man-made product, so there is undoubtedly a process that goes into creating it. Manufacturers of the fabric begin with a reaction between ethylene glycol and dimethyl terephthalate. Using high heat, the reaction develops a monomer.

Follow reaction number one is reaction number two. Once the monomer has been created, experts then force a reaction between the monomer and dimethyl terephthalate again. This results in a polymer.

The resulting polymer comes in the form of molten material. It then goes through a process called extruding by entering a reaction chamber in long strips. The strips then sit to cool and dry. Afterward, they get broken down into small pieces.

From here, the small pieces get melted down once again to form a thick substance similar to honey or syrup. This material is once more extruded through a spinner, which creates the polyester fibers.

Finally, after the spinning process is complete, manufacturers can cut the resulting filaments. They can also further react with other chemicals to create mixed blends or other materials.

Is Polyester Waterproof?

Before we answer this question, there is a significant differentiation that we have to make. Regardless of the product in question, the terms “waterproof” and “water-resistant” are often used interchangeably.

The truth of the matter is that they have two different meanings. Otherwise, why bother using another word?

Waterproof, at its basic definition, means a material is 100% sealed off from the entry of any water at all. One of the most common methods of achieving a fully waterproof product is ultrasonic welding, which joins non-synthetic fibers without using thread.

The term “water-resistant” most often truly means “everyday waterproof.” In direct contact with water or extended exposure to moisture, these products will take on water. However, they’re suitable for minimizing wetness during everyday situations – such as running to your car during a rainstorm or walking through the snow.

Polyester on its own is not waterproof, but it is water-resistant. The reason polyester is not waterproof is because the fibers of the material are woven together. Even with the tightest of weaving, there will still be microscopic cracks and air gaps through which water can navigate.

That being said, polyester fibers can be woven in a way that makes the material extremely dense, which is why it makes an excellent water-resistant material. On top of that, there are other things you can add to help increase its resistance to moisture.

How to Make Polyester Waterproof

Like we said earlier, yes: polyester is a super standard fabric used across a wide variety of products. But as we also talked about: polyester, in and of itself, is not waterproof.

The two facts above combined come out to equal a major bummer for anyone with a polyester product that may come into contact with water. Thankfully, there are ways that you can make polyester waterproof material.

In short, products such as spray-on sealer, iron-on vinyl, and other DIY methods can transform your polyester and protect it from moisture.

We’ll share a future article on strategies for waterproofing polyester. Stay tuned!

The Last Drop

That’s about it! In short, polyester is water resistant, but not waterproof.

If you’re interested in the technical makeup of other fabrics and which ones are waterproof (okay, maybe it’s just us), check out the guides below.