How do Magic Erasers Get Rid of Stains?

By: Jessika Toothman  | 
Got kids? You'll probably benefit from keeping melamine foam erasers on hand.
Photo Courtesy of BASF

Eraserlike products that get rid of stains you thought you were stuck with for good are now a staple in the cleaning aisle of the supermarket. For example, Mr. Clean sells a line called Magic Erasers, and Scotch-Brite offers a product called the Easy Erasing Pad.

The secret behind these types of erasers is a material commonly called melamine foam. With just a little water, melamine foam can dig in and destroy stains that other products can't touch. Kids go crazy with the crayons? Co-workers leave a trail of scuffmarks wherever they walk? Erasers made with melamine foam might be just what you need.


Stain removal isn't the only thing this special foam is useful for. It's actually been around for about 20 years and has a variety of applications, such as sound insulation (whether to improve a room's acoustics or dampen excess noise) and temperature insulation (whether to protect against very hot or cold temperatures). It's just recently that developers realized its potential as a cleaning product.

A couple of melamine foam's specific physical properties make it a great stain remover, and we'll dive into what those characteristics are on the next page.


Erasing Stains With Melamine Foam

Illustration of Magic Eraser structure
Get up close and personal to see what is going on inside a melamine foam eraser.
Photo Courtesy of BASF

Magic Erasers, Easy Erasing Pads and similar products all have the same key ingredient: melamine foam. Melamine foam erasers are formed differently from other cleaning products and only need water to effectively clean most stains -- no chemical cleaners or soaps required. The only downfall is that melamine foam erasers wear out quickly -- just like pencil erasers do.

To all outward appearances, however, melamine foam erasers look and feel just like any other sponge. To view the crucial properties of melamine foam, you need to go down to the microscopic level. This is because when melamine resin cures into foam, its microstructure becomes very hard -- almost as hard as glass -- causing it to perform on stains a lot like super-fine sandpaper. You may be asking yourself, if this foam is almost as hard as glass, then how can it be like a sponge? Because it's a special type of open-cell foam.


Closed-cell foam is easier to visualize, so let's start there. Types of closed-cell foam are usually more rigid because they retain most of their air pockets intact, like a bunch of balls all crammed together. For open-cell foam (typically the more flexible) imagine that those balls have burst, but that some sections of their casings still remain. You can picture a squishy sea sponge as an example. In airy melamine foam, only a very limited amount of casing stays in place, and the strands that do are located where the edges of several air pockets overlapped. The foam is flexible because each tiny strand is so slender and small that bending the entire eraser is easy.

­­The cavity-ridden open microstructure of melamine foam is where the second major boost to its stain-removing capabilities comes in. Apart from being able to scrape at stains with extremely hard microscopic filaments, with a few quick runs of the eraser, the stain has already started to come away. That's aided by the fact that the dirt is pulled into the open spaces between the spindly skeletal strands and bound there. These two factors combined make this next-generation eraser seem almost magical.

Ready to start erasing some stains around your house? Now that we've unlocked the mystery to melamine foam erasers, check out some of the links that follow for more interesting information.


Lots More Information

Related HowStuffWorks Articles

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