What is Porous Plastic?

By Avi Robbins (VP, Global Product Development and R&D)
Dec. 13, 2019

You may have heard the term porous plastic but aren’t quite sure what it means. The term is fairly common among engineers and R&D teams as they source materials to build products. But, what exactly is porous plastic? We’ll explore what this material is and what it can do.

Porous plastic defined

The simplest definition of porous plastic is a breathable, versatile material that’s used in a lot of different products. The complex definition is a bit more scientific.

Engineers fuse particles together to create a breathable microporous structure. The result is a durable, design-flexible component that can control the flow of gases, liquids, light, or sound.  

It’s probably best understood by looking at a few examples. Foam applicators used to apply makeup are made of porous plastic, as are the wicks inside plug-in air fresheners and the nib on your highlighter used to apply the ink. In both cases, the end product requires a high level of control over the flow of gas and liquids inside it.

With the makeup applicator, the material has to wick yet absorb enough makeup for application. With the air freshener, the wick slowly diffuses the liquid fragrance into the air. Both products require a component that helps control the flow of gases and liquids.

The types of porous plastic

There are three main types of porous plastic. Here’s a quick description of each:

  • Sintered porous plastic: Various polymers or particles are fused to create controlled pore sizes, which creates a strong, self-supporting material.
  • Bonded fibers: Bonded fibers create materials with a wide range of fluid transfer abilities, which are great for medical, industrial, and consumer products.
  • Open-cell foam: A customized blend of materials with varying pore sizes, densities, and softness, the open-cell foam is commonly used as medical-grade and cosmetic foam to absorb fluid.

What porous plastic can do

At Porex, our porous plastic can be used in many different ways, including:

Plastic polymers are made into porous foam or porous fiber solutions.

Example: Doctors use medical foam made from porous plastic for wound care.

Porous solutions can enable a fluid to be applied to a surface.

Example: The soft applicators used to apply eye or lip liner are often made of porous plastic.

Porous solutions can spread liquid, gas, or light evenly.

Example: Reed diffuser wicks release a consistent fragrance into a room.

Porous plastic can allow liquid, gas, light, or sound to pass in order to remove unwanted material.

Example: A small filter inside nasal spray keeps contaminates out of the medicine and allows for repeated use.

Vents created from porous plastic improve a product’s functionality and lifespan.

Example: Inside car headlights are automotive lighting protection vents that minimize humidity and maximize brightness.

Transferring liquid through capillary action is possible with porous plastic.

Example: Wicks inside pregnancy tests deliver a controlled amount of liquid to the test strip that provides the results.

Chances are high that, if your product moves fluids or gases around in some way, you would benefit from a porous plastic material. If you believe your product needs a porous plastic component, it’s easy to talk with an engineer or request a sample .