Memory foam, or visco-elastic foam, is made of polyurethane. Convoluted foam, commonly referred to as egg crate foam, is made of polyethylene. They are similar materials, but create vastly different products.
Memory foam is dense and extremely viscous and energy absorbent. This is why memory foam is commonly used in all types of items ranging from padding car seats, to astronaut and football helmets, to memory foam mattresses and mattress toppers.
Egg crate foam is usually less expensive than memory foam, which makes it a popular choice for bed toppers. The peaks in the foam’s design create a soft, almost squishy surface. However, egg crate foam is not as energy absorbent as memory foam, meaning it does not hold up well under pressure. While the use of egg crate foam as a mattress topper, or in cushions can help relieve a little bit of pressure from bodily pressure points, it simply does not compete with memory foam in minimizing pressure point stress. Also, egg crate foam is not as dense as visco-elastic foam, meaning it is not nearly as supportive. This is why many shoppers seek the slightly more expensive memory foam mattress toppers.
Though visco-elastic foam is the superior choice for comfortable sleeping and minimizing strain on bodily pressure points, the egg crate version still has many uses, other than in packaging materials. Convoluted foam makes great padding for seat cushions where people are unlikely to sit for long periods of time. It is often used in mattresses in addition to memory foam, particularly in the top comfort layers. Because it is much less dense, convoluted foam weighs less than visco-elastic foam. Using the two in tandem in new mattress comfort layers helps add support and softness, while minimizing the total weight of the mattress. This is especially important in the larger size king mattresses and queen mattresses.
Though convoluted egg crate foam is not as dense as memory foam, and does not offer as much pressure point protection or as much physical support, it still has many uses in making everyday products more comfortable. Having convoluted foam does not mean a mattress will necessarily be less comfortable than a mattress that uses memory foam, though it might have a different feel to it. That said, it is important that mattress shoppers be aware that the two are not the same, in order to find the mattress that best suites the shopper’s needs.