What Is A Memory Foam Mattress Made Of


January 9, 2024

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What makes memory foam mattresses so good? It's all about the materials. We will dive deeper into what a memory foam mattress is made of and cover these; 

  • How memory foam is made and its history
  • How to sleep on a memory foam mattress?
  • What makes a good foam mattress?
  • Are memory foam mattresses any good?

In memory foam, polyurethane is primarily used along with chemicals to increase its density and viscosity. It is also known as viscoelastic polyurethane foam or low-resilience polyurethane foam (LRPu). Open bubbles or 'cells' in foam create a matrix in which air can move.

Memory foam history and construction

Efficient mattresses don’t just offer a good night’s rest but also keep your back pain in check. It’s evident from stats that around 16 percent of the Australian population suffers from back pain.

Much of the back pain originates while sleeping. Also, a lot more weren’t satisfied at all with the quality of sleep they were getting. So at this point, it won’t be surprising that the answer might simply lie in the mattresses.


NASA perfected the concept of memory foam. Yes, we’re talking about the National Aeronautics and Space Administration. The concept isn't even close to new. The collaboration between Stencel Aero Engineering Corporation and NASA occurred in the 1960s. 

Charles Yost invented memory foam in 1966 while he was trying to create padded seat cushions for NASA spacecraft that could withstand the pressure caused by G-forces during takeoff. Even though NASA didn't use his design, it appeared in car seats, medical equipment, and eventually mattresses.

Memory foam construction

Memory foam is also known as viscoelastic foam, which belies its essential properties: it becomes viscous and elastic when subjected to heat and weight. As a result, it’s excellent for relieving pressure on sensitive parts of the body like the back, shoulders, hips, and spine.

To give memory foam its viscosity, polyurethane polymer is combined with hard-working chemicals. 

What chemicals are in memory foam?

Memory foam is made of polyurethane foam, containing three different chemical components: polyols, diisocyanates, and a carbon-based blowing agent. By combining these three components, a chemical reaction is triggered, which produces a liquid. As the liquid cools, it hardens into foam.


In a reaction with isocyanates, polyols are converted into polyurethane foam. The foam's bulk is polyols.


Diisocyanates are commonly used to make rigid and flexible foams (such as memory foam products), sealants, adhesives, and more. There are two types of diisocyanates used to make memory foam: MDIs and TDIs. You're likely to see MDIs in home insulation, sealants, weather-resistant materials, or binders. TDIs are most common in furniture, bedding, and packaging. For example, mattresses contain large quantities of both TDIs and MDIs, but they are not carcinogenic.

Carbon-based blowing agents

In the process of converting liquid to foam, blowing agents are used. Chlorofluorocarbons (CFCs) are the most commonly used blowing agents in memory foam. Today, many mattress makers use safer blowing agents, such as water.

VOCs are organic compounds that are produced by the three materials listed above. For example, it is typical for a newly opened memory foam mattress to emit a chemical smell - these are VOCs. Exposure to VOCs is not harmful, but it may irritate those with allergies or respiratory problems. Off-gassing odours usually dissipate after a day or two, but if they persist, you can open the windows and air the room out.

Can you cut memory foam mattresses?

Memory foam, latex, and general foam mattresses are easy to cut. Mattresses with pocket springs can also be cut, but it requires a bit more effort. You just need the right tools. 

Choosing the right cutting tool: Electric vs manual

It is possible to cut your mattress with a general-purpose kitchen knife or box cutter and a scissor, but it will be time-consuming, require elbow grease, and the cut will not be straight.

A decent electric knife or hot knife (both costing about $20) will make the job a lot easier, and you can use them later for other things as well.

It comes down to personal preference, and both are good options. Electric knives are easy to handle, make straight cuts, and aren't too expensive.

The best way to cut a mattress - desired size or half size

Whether you want to cut your mattress in half or create custom dimensions, follow these steps.

The following equipment is required:

  • [Paid options] An electric carving knife, electric bread knife, hot knife, box cutter, or hand saw.
  • [Common household items] Bread knives or utility knives.
  • If the mattress cover is not removable, use dressmaker shears or a sharp scissor to cut it.
  • To measure dimensions, use a measuring tape or a ruler.
  • Pencil or marker to mark the cutting line.
  • [Optional] Seam ripper for opening mattress covers. This step is only required if you want to save the mattress cover.
  • [Optional] T-square or straight edge plywood or cardboard for precise cuts.
  • [Optional] Sewing kit and thread to re-stitch the mattress cover. Also, you can use a staple gun or glue gun to stick the fabric together (not the best fix, though).

How to Cut Memory Foam, Latex or All-foam mattresses.

Step 1: Place the mattress on a firm surface, such as plywood or cardboard. If you're cutting the mattress on the floor, you don't want the knife to damage the bed frame or flooring.

Step 2: Next, remove the outer mattress cover. Unzip the outer cover if it is removable. Using a seam ripper or scissors, you can cut the cover along one of the seams if the cover is not removable. The cover should be cut carefully along the seam if you plan to reuse it.

Step 3: Use a pencil or marker to mark the exact dimensions of the cut on the foam layer. Using straight edge plywood or cardboard, measure the distance between opposite ends of the cut and mark the straight line.

If you want to cut the mattress in half along the length, measure the middle point on both ends (width-wise) and join the points with any straight edge.

Step 4: Make light incisions along the marked line with your tool of choice (electric or normal knife, bread knife, saw, box cutter, etc.). Avoid compressing the foam while cutting.

You should make several shallow cuts until you have cut through the entire thickness of the foam. In general, the bottom layer is denser and harder to cut. When cutting, use a sawing motion instead of a slicing motion, as it will give you cleaner cuts. To ensure a clean, straight cut, apply even pressure while cutting.

When using an electric knife, you should make multiple passes rather than trying to cut through the entire thickness in one pass, since it might get stuck, and you might end up with uneven cuts.

Step 5: Cut off any excess foam. Using a utility knife or scissor, remove any excess foam that's hanging off the edge once you've cut through the foam.

Step 6: The final step. Your mattress is now divided into two pieces. The mattress cover can be stitched back together, glued, or wrapped in a fitted sheet to create a custom-sized mattress.

Is polyurethane foam the same as memory foam?

Not at all. In contrast to memory foam, polyurethane foam, or poly-foam, is different. This type of foam is cheaper, and therefore of lower quality.

Likewise, poly-foam comes in different densities, but the higher the density, the more durable the foam. While it can provide some cushioning, it does not offer the same level of individualised support as memory foam. You will commonly see this material as a support layer to a memory foam comfort or top layer. However, this will be high-density polyurethane foam for durability.

What is reflex foam?

Memory foam is very similar to reflex foam; it's just constructed differently. Although faster reshaping is one of its distinguishing characteristics, and it’s a little firmer than memory foam, it makes a great base layer or component for supportive orthopaedic mattresses.

What is medical grade foam?

Orthopaedic and medical memory foam is designed specifically to relieve chronic back pain and joint ache. To provide extra cushioning around joints and problem areas, the foam is carved with grooves and channels.

What is the difference between foam and latex mattresses?

Heat and compression are used to bond latex particles into a solid form. Both synthetic and natural latex can be used to make mattresses.

Latex does not soften when in contact with body heat, so some people may find it too firm. Also, natural rubber has excellent eco-credentials as well as being a durable material.

Is a hybrid mattress better than memory foam?

Not always. Depending on your sleeping style and preferences. Hybrid mattresses combine the best features of several mattresses into one. For added comfort, spring mattresses are often combined with a layer of memory foam.

When you have specific sleeping needs, like getting too warm at night or having different mattress support standards between you and your partner, a hybrid mattress could be the right solution.

How to sleep on a memory foam mattress

Don't worry if the mattress feels a little firm here and there. The more you use it, the quicker it will adapt to your needs. This is due to its viscoelastic properties. 

If you don't want to wait that long, you can also increase the temperature of your bedroom. Now let's talk about sleeping on a memory foam mattress. Then, when you get out of bed, the foam springs back to its original shape after a short time.

Unboxing the memory foam mattress

Step 1: Go ahead and get the mattress out of the box.

Step 2: Lay it down on your bed.

Step 3: Remove the vacuum-sealed packaging and unfold it.

Step 4: Let it sit until it takes the shape of the mattress.

Try to leave it as long as possible before sleeping on it, usually 24 hours.

Sleeping positions

You can sleep on a memory foam mattress in a variety of ways. Here are a few of them.

Side sleepers

In the long run, sleeping sideways is not only comfortable but also good for your health. If you like to sleep on your side, memory foam mattresses provide excellent pressure relief and are perfect for you.

Front sleepers

Spine overarching is common if you’re sleeping facing the mattress. Since a memory foam mattress adapts to the shape of your body, it provides support for your spine. But most memory foam only mattresses might be too soft to get proper support in this position.

Back sleepers

Sleeping on your back has many health benefits. The reason is that when you sleep in that position, you're able to distribute your body weight on the mattress evenly.

However, it might also be the reason you wake up with sore lower back muscles. When this happens, it is a clear sign that you need to change your mattress. If you are, there's nothing better than a memory foam mattress.

Memory foam benefits

Memory foam mattresses can significantly impact sleep and spinal health. Among the benefits are;

  • Pressure relief
  • Durable and long-lasting
  • Suitable for different body types
  • Support and comfort of the highest quality
  • Dust-mites are prevented from entering with high-density foam
  • Your partner's tossing and turning will be minimised by movement absorption

What is a good foam mattress?

A good foam mattress will have multiple layers of foam and a study base which would generally be high-density foam. Due to this, the mattress can provide excellent breathability and support. Below are two excellent memory foam mattress picks.


Emma stands at the top of the memory foam mattress world. So when you are looking for a mattress that offers high reviews and fantastic comfort, this is the mattress you should consider.

More so, its layers of foam provide the perfect comfort level for side sleepers. Plus, if you love memory foam, get yourself mattresses from Emma. For more information, check out our Emma mattress review.


Koala is a brand that perfectly reflects the sleeping needs of Australians. It offers mattresses that are "not too firm, not too soft." In addition, Koala foam mattresses are eco-friendly. They have, however, recently moved production of the mattress to China to cut costs, but the reviews haven't mentioned the quality of the mattresses they offer. Read our Koala mattress review for more.