Memory Foam: Curious What it is and How it is Made?

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Memory foam mattress as known is among the top rated and most sold among mattresses and pillows. Many types of memory foam and many more brands make it confusing in making a choice. It helps to know what memory foam is made of and how it can serve before making a purchase.

What is memory foam made of?

Memory foam is made from a host of chemicals that are processed in sophisticated machines. The foam goes through a baking and moulding procedure to form a mattress.

Components of polyurethane foam

To know about memory foam it is important to distinguish between polyurethane foam and memory foam. Polyurethane foam is made by mixing Polymeric polyols such as plant-based oils or glycerine with highly reactive Isocyanates that are mostly used to make rigid foams.

Polyurethane foam is generally low density and inexpensive. It is mostly used as a top layer in innerspring mattresses. It collapses much quicker to pressure and doesn’t provide the same support as memory foam.

Components of memory foam

The main component of memory foam or viscoelastic foam is polyurethane that is made by mixing hydrocarbons, commonly found in petroleum with water. Memory foam is then formed by mixing additional chemicals to this polyurethane foam.

Manufacturers then use other compounds additives, blowing agents and processes that form an open cell structure and make the foam softer. Other additives like fire retardant chemicals and surfactants are also added.

The process of making memory foam

Producing memory foam is a complex procedure that takes almost 8 hours. The procedure is essentially a mixing process of water, polypols, isocyanates and other reactive substances.

The most common type of isocyanate called diisocyanate dissolves completely in these highly reactive processes. This produces memory foam without any residue of an isocyanate.

The reaction of these various components is a 5-minute process that forms a liquid-like consistency. This liquid is then filled into molds that form slabs of memory foam. This mix sprayed into molds is then dried quickly to form the foam or memory foam product.

The procedure also involves a method of forcing air out that causes the well-known open cell characteristic of memory foam to make it breathable. The slabs are then cooled, washed and transferred on to conveyor belts. They are then cut into various shapes and dimensions of a mattress.

Polyureathane as that forms a major part of memory foam is combustible. In contact with heat, it can burn and cause major fires of high toxicity. It is for this reason that the foam is then treated with fire-resistant substances.

Different manufacturers use different formulas and chemicals, which cause different types of densities and properties. This then forms the basis of marketing for a particular brand or product range.

Memory foam mattresses are made of both density and firmness

The manufacture and marketing of memory foam are not complete without determining firmness and density.

An important factor that differentiates one memory foam mattress from another is its density. The many types of memory foam are made of different levels of density.

Memory foam that is made denser is typically more durable and long-lasting. Higher density is also associated with the better ability of the foam to provide support.

Memory foam mattresses are made of a number of layers that vary in density. Typically, the top layers of the mattress are made of less dense memory foam than the core or base supportive layers.

Density is measured in pounds per cubic foot and the top layer of the mattress could be made of memory foam with density ranges of 1.1lbs to 1.8lbs. The lower layers could be made of memory foam with density ranges of 1.6lbs to 3.0lbs.

Indentation Force Deflection (IFD) or Indentation Load Deflection (ILD) is the measure of firmness of memory foam. It must be known that memory foam that with high density can be made to have either a soft or a firm feel.

What is gel memory foam mattress made of?

Traditional memory foam attracts heat and becomes less viscous, as it gets warmer. This makes it sink in relation to body pressure. As the memory foam heats body and room temperature, it gets laxer and sinks more. This process traps heat and makes sleeping warm.

Memory foam is thus infused with gel beads on the topmost layers of mattresses to dissipate heat. These memory foam mattresses are made of two types of gel forms. One has low thermal conductivity and feels cool to touch. The other types are reactive and release heat in relation to temperature changes.

What is plant-based memory foam made of?

While most memory foam products used petroleum, plant-based varieties use plant oils or botanical oils in their manufacture. These plant oils could be derived from substances like soybeans, castor beans or canola.

These plant-based oils are then modified to create biopolypols which are then are combined with isocyanates. Most of these memory foam products are free from harmful chemicals.

However, most of these memory foam products are made of a combination of petroleum and plant oils. Typical combinations are 25% plant oils with petroleum forming the rest.

Quality of memory foam mattress

Many manufacturers make a number of memory foam products to provide buyers with a wide selection and price range. However, attempting to reduce costs, downgrades the quality of memory foam used. Besides, many companies produce their memory foam overseas that may not adhere to quality standards.

It is thus advisable to invest in memory foam products with suitable certifications that meet certain standards or ones made in the United States. CertiPUR-US, is one such certification that assures buyers that the memory foam meets certain criteria and environmental standards.


Different manufacturers use different contents and processes to make a wide variety of memory foam. Narrowing down on a product would depend on your needs and budget.

While gel based foams are cooler, high-density foams are better for support. Look out for certifications and seals that guarantee you’re making the right choice.

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