A note on convoluted foam (aka: egg crate or acoustic foam)
Convoluted foam was designed as an inexpensive method of doubling foam production. By splitting the foam in half and carving points into it (like an egg crate), you get two 4 inch thick sheets of foam out of one 4 inch thick sheet of foam. This is great for acoustic reasons, or to lower cost of packaging in crates, cases etc.... but this type of modified foam does not belong inside a mattress.
In recent years, mattress manufacturers have been looking for way to cut costs. So along comes the use of acoustic foam. Since they can double their foam production by making convoluted foam, they began to use egg crate foam inside the core of their mattresses. This is great, as they get the same mattress thickness, while saving money! The only problem is that you are paying for air, because half the original foam is missing! Everyone agrees that you need a minimum 2 lb density poly-foam for a durable support core. Convoluted foam removes half the weight of the foam, so you are left resting on small foam spikes (egg crates). In our opinion this weakens the support core and is insufficient for proper orthopedic support because the egg crates eventually collapse as a result of excessive body weight.
In order to promote the convoluted foam layer as a good thing, they give it a fancy name like an airflow system. However it's simple to see how this system fails. Since there is no way for the warmer air from the memory foam sleeping surface to reach the convoluted foam layer in the center core of the mattress. Plus there is no air left inside the mattress anyway, because the foam egg crates are crushed by your body weight and pressure.
Here is an example of this marketing hype and the actual customer comments
Under SLEEPS HOT and more here.............
We have been selling mattress toppers for over 15 years. Our biggest complaint from customers, is that their mattresses are just not as comfortable as they used to be. The reason is simple, most bed manufacturers add a pillow top to their spring mattresses. These pillow tops are usually made of a thin layer of low density convoluted foam and some poly-fill. It feels great at first, but in a short while it flattens out and then the pillow top comfort layer is depressed. That's good for us, because they end up buying a 5lb memory foam topper to save their mattress.
The second problem we encounter, are those trying to fix a mattress that is sinking and offering less support than it used to. The most common cause for this weakness is the use of low density foam, or a layer of convoluted foam (or both) in the support core. Unfortunately we cannot solve this problem, as the source of the dilemma lies in the mattress support core. The only option left for the disappointed customer, is to live with this issue, or buy a new mattress!
The proper way to build a mattress, is to use solid, non altered, high density foams in all layers of the mattress. This method is unpopular as it results in more expensive mattresses. However, the outcome is increased durability and proper support, because the integrity of the mattress has not been compromised by convoluted or lower quality (density) foams.