What would be the property or properties that would the same volume of gel memory foam softer or firmer? Would that be density?
I’ve tried googling this, and even looking on this site, but it’s really not clear.
The differences that I see in the ‘soft’ memory foam mattresses is simply that layer(s) of memory foam are thicker. That is not what I am asking or looking for.
I want to know, if you have a 2" layer of foam, what makes one harder to squeeze with your hand than another 2" layer?
My son has a 2" gel MF topper, and I ordered the exact same one about 9 months later. However, the new one - same company, same product, everything - is noticeably firmer (read: harder to compress). Does gel-infused foam soften with age?
I want the softer/squishier version, but I don’t know how to find it because I don’t know what properties I’m supposed to be looking for.
Also, I am fine with giving up ‘durability’ for comfort - being uncomfortable on a firmer bed for a longer period doesn’t sound in any way enticing…
Thank you!
Hi latexintheatx,
Memory foam is produced by reacting an isocyanate and with polyol in presence of a catalyst, water and other additives, and through the manipulation of catalysts and surfactants, partially open cells can be produced, which help create the slow-recovery part of the memory foam process (air is slower in moving in and out of the foam). Another way to create a memory foam (more common) is to manipulate the catalysts and polyols to control the viscoelastic polymer structure, which changes the hydrogen bonding and the glass transition effects in the polyurethane soft phase. So the viscous nature of visco-elastic foam is hence altered. I was reading an article from a chemical R&D director which stated succinctly that the memory foam is designed on purpose to be a poorly performing spring (polyfoam is a polymeric spring). The specific ratios and additives that foam manufacturers use would be closely guarded trade secrets and you would not find this information shared online. They can vary the firmness, the recovery time, the sensitivity to temperature (viscous nature) and so on. Density and hardness aren’t necessarily related in memory foam, and all memory foam is generally quite plush (ILDs in the 8-18 range are quite common).
While that is not always the case, with more plush material on top of the firm polyfoam core in a typical mattress, there would be more comfort material, which in general in a memory foam product would result in a softer overall feel.
All foam softens with use over time, so it would be normal that a new topper would feel firmer than an old one. This is assuming that the foam is exactly the same, which you wouldn’t know from the packaging. Manufacturers will make running changes in formulations quite frequently, and there will also of course be variations in foam batches.
The only true way to tell this would ultimately be through your own personal testing. Higher density memory foam will be more durable, but that won’t tell you the speed of recovery, temperature sensitivity, or the overall softness (overall ILD is difficult to measure in memory foam). A conversation with the foam supplier you are considering would be helpful, as they would be in the best position to put into “layman’s terms” how their different memory foam topper options would compare to each other.
Phoenix