Hi Offthelake,
Acella-flex polyurethane foam is made by Sleep Innovations (originally made by the leggett and platt foam division which was bought by sleep innnovations) and like all polyfoams can be made in many different ILD's and densities. Typically it would be about 33 ILD and 2.0 lb density (such as used in the
ecosleep mattresses) . This would be considered a good quality HD polyfoam and suitable for use mattress core.
The "green" poloyfoams typically use either soy or castor oil to replace part of the petrochemicals in the foam and the percentage that is replaced is typically under 10% although in some cases it is more. While it is certainly a step in the right direction ... thy can hardly be called "green". Acella Flex replaces from 3% to 6% of its oil based polyols with plant oils. Green, soy based, or plant based foams are not a new category of foam (in spite of what many mattress outlets or salespeople will tell you), they are simply a new "buzzword" for polyfoam which has had a small percentage of its oil based polyols replaced with chemically altered plant oils. Even calling soy based oils "green" is a misnomer since soy is a crop which is a major contributor to the destruction of the South American rain forest. More about soy based polyols and green foams here
www.bedtimesmagazine.com/Articles/2010/F...ingTheSpotlight.html
Denser memory foams are usually softer than the less dense memory foams (they have smaller cell structures) and of course more durable and typically slower to respond (have a longer memory). I understand how you like the feel as I also prefer the feel of a layer of denser memory foam in a comfort layer. They are more difficult to find though as many manufacturers reserve their denser and higher quality foams to manufacturers or to higher quality outlets to "prevent" their foams from being "lumped in" with cheaper lower quality foams.
In general ... 4lb memory foam from a reputable manufacturer would be the best quality that can be reasonably be expected to be used in a low cost memory foam mattress. Genuine higher quality is certainly available but the cost goes up.
I would only consider using memory foams where the manufacturer or sales outlet discloses the source and density of their foam and it can be verified that it is certified by Certi-Pur. Oeko-Tex class one certification would be preferable as it is a "tougher" standard (suitable for use with babies) however I doubt that there are many polyfoams or certainly memory foams which would pass this standard. Most Talalay latex and high quality Dunlop latex passes Oeko-Tex class 1.
I have talked with AstraBeds and our conversation became somewhat "difficult" when I questioned some of the things I was being told. They may have been having a bad day however and they are better value than others on the internet although not in the same value range IMO as the manufacturers that are members here. The conversation was a little too "high pressure" for my liking. We did not discuss his memory foam products. Like all memory foam products and outlets ... I would only consider an outlet that fully disclosed the source of their memory foam ... especially when they are selling higher densities which are often sourced in China. High density/quality memory foams are more expensive than lower densities and when I see high density prices that are very low I certainly would ask some questions and make sure I was satisfied with the answers.
In the case of memory foams which use the name "ecocell" ... these are made by
Dormeo which is an international drop shipper of memory foam mattreses. Their "typical" memory foams are 58 kg/cu meter (3.62 lbs/cu ft) so I would take the claims of an 8lb foam with a grain of salt and would certainly verify the actual weight. Many memory foam sellers measure their foam per 2 cubic ft which would make their foam seem to be twice as dense as it really is. I don't know if this is what is happening here however I would seriously question a claim of 8 lb memory foam at these prices. These "cheap" ecocell memory foams are widely available on the internet.
An example of a true high quality high density memory foam mattress (using Foamex foams) is here
www.chirosleeper.com/chirosleeper-diagram.htm however it is not "cheap" (sells for a little under $2000 in queen). An actual mattress manufacturer will usually give you memory foam information that can be more trusted to be accurate. It is generally not worth purchasing memory foam from unknown manufacturers or from outlets that are not transparent about their memory foam.
Hope this helps
Phoenix
