I have found that this form has an excellent source of information in its archives. In fact, quite frequently, some of the more interesting posts are found in the archives. For instance I found this piece listed in 2007. JimSoCal you should find this quite interesting. http://www.whatsthebest-mattress.com/forum/polyurethane-foam-association/31-0-1.html This message was modified Dec 2, 2009 by eagle2
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For those people who are really interested in knowing about what makes foam firm or soft, supportive or less supportive, then the information contained in this link should be of interest to you. |
This post is based on pure curiosity. I have a question. Can anyone tell me why it is that this thread has received so little notice, or comment, from those folks who claim to want to know all about foam and its firmness and supportive characteristics? There is more information in the links that I have provided regarding the subjects that anything that I have found anywhere. For instance. The difference between ILD and density of foam is extremely important to the understanding of the support that foam provides. Yet this thread has been on this forum for quite some time with no response whatsoever. Why do you suppose that is? |
Eagle, from the wording it looked like it was aimed mainly at Jimsocal and not totally clear what the topic was. So, people may have skipped over it. In reading it seems that density is a factor independent of ILD. A higher density will provide more support than a lower density foam with the same ILD. Possibly why you found the blended piece to be softer. And why dunlop feels firmer as well. At times I do feel like I am sinking in too much on the blended latex, so possibly the 100% natural or dunlop has advantages (especially for heavier people). |
Thank you for your response Sandman. I have changed the heading of this thread possibly that will help. I just think people need to read more to know more. What is the use of asking the same questions over and over again if were not willing to learn from what's already knowable? And I believe you are right about the blended piece of latex that I received from FloBeds. It is a 32 ILD but it feels like my medium hundred percent natural that as an ILD of 28. But the density factor comes into play. The blended piece is about 2 to 3 pounds lighter than my medium piece of hundred percent natural. Therefore they feel relatively the same. The thing is, that this post that I made has links to some PDFs that gives some very explicit information about this difference. It is one of the most informed pieces of information that I have found on the Internet. This message was modified Dec 2, 2009 by eagle2
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Do you know if 32 ILD blended (or natural) is denser than 28ILD.? If so, then you can pretty much offset the difference between the blended and natural by just going for a higher ILD in the blended (as you noted before). However, they still would not feel exactly the same. I would also note that the 25% test to measure ILD is an arbirtrary number. If they used 50%, for example, then 2 pieces that have the same firmness under the 25% measure might now measure to a different firmness. Perhaps the denser all natural or dunlop would measure higher with a 50% (or some other %) standard. Therefore they effectively feel firmer than the blended when your body weight compresses them by more than 25%. |
All anyone has to do is read the PDFs provided in the links to have a more clear, and comprehensive understanding of what is going on with the variances in foam. There are precise scientific approaches to rating foam. The problem will come in trying to find companies that adhere to these standards. That is why I believe that dealing with the first tier providers of latex is going to bring the customer closer to actually achieving their desired results. I'm not saying you cannot find individuals selling pieces of foam to the public that are dealing honestly and properly with their product. What I am saying is, at least for my reading on this form, and on the various websites of these foam manufactures, is that it is very difficult to really know what you're purchasing. For instance in the links provided they talk about" fillers" used by many manufacturers to do various things to their foam. This completely throws off the ILD and density ratings. I also found it quite interesting to learn that it is possible to manufacture foam that is both dense and soft as well as less dense and firm. So the point is, there is a lot more to this business than I previously thought. And this may explain why so many people are having difficulty finding a piece of foam that is satisfactory for them. When you cannot believe the specifications posted about a piece of foam how can you possibly be expected to find one that will work for you? The truth of the matter is we wind up believing whatever they say on their website and buying by price. Then when we get the foam we are disappointed in the results. This is one of the reasons I decided to go with FloBeds. They have well over seven years with no negative BBB reports. They must be doing something right.
For instance, consider this. From one of the PDF's. "Obviously, the denser the foam, or the more materials used to produce it, the more material there is in the cushion (mattress) to provide support for weight. It is important to remember though that foam surface firmness is independent for foam density. High density foams can be produced to be very soft. Low density foams can be made to be very firm. Therefore, there is no such thing as, "hard" or "firm" density. High density foam products generally offer a great deal of support but they may actually be fairly soft foams. What's the difference between firmness and support? Firmness,(25% ILD) is a measurement of the surface feel of the foam. Support is the foam’s ability to push back against weight and prevent the foam from bottoming out. Higher density foams help prevent the feeling of having the foam collapsed beneath bodyweight in any application. Both firmness and support affect foam comfort. There is even a measurement to determine the foam's ability to provide support. This measurement, "support factor", is determined by measuring the firmness (ILD) of the foam by compressing it 25% of its original height (a 4” block of foam to 3”) and then measuring the firmness when compressing the same foam sample to 65%. The ratio of the 65% ILD rating divided by the 25% ILD rating is the foams support factor. The better the support factor, the greater the ability of the foam to support weight. Foams with support factors of 2.0 or above are better suited for loadbearing applications like mattresses or seat cushions. Density also translates into foam durability. Again the more polymer material used to produce the foam the better foam tends to retain its original properties” Read the Polyurethane Foam Association's PDF’s! There is a lot of important information in their. This message was modified Dec 2, 2009 by eagle2
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It seems like dunlop and 100% naturual Talalay will have a higher support factor than blended Talalay. Not sure how much though, since it seems hard to find any data. The suport factor for "latex" that I found was around 2.6. That is probably dunlop, but not sure. |
Eagle2, I never replied because I just have not had the time and/or felt like reading technical info about foam. I should have said , "Thanks for the links. I'll read them at a later date. But don't have time right now." For me it's very much about just trying stuff and seeing if it works. I totally agree with you that knowledge is important, and I think a certain amount of basic info is essential. On the other hand, I'm not sure everyone needs to get a PhD in foam in order to figure out what they like. To do that, to me, the best method is to try certain ILD's and densities out and see how they feel. I mean, I have a "feel" for how HR is different from Omalon and how Omalon is different than M-Grade and how polyurethane is just a very low density crappy version of those. And I know that Dunlop feels denser than Talalay to me, and I know that memory foam can be denser or less dense and to me the more dense almost always feels better in memory foam, in fact I'd like it denser than any I've tried. So I guess I'm saying that in my humble opinion, knowing a lot about foam isn't AS important as experience. Also, a lot of times, it's an economic factor. If you can't afford latex, try M-Grade or HR high-density polyurethane. Anyway, all that is neither here nor there. Eventually I'll get around to reading the articles you posted! Thanks. (And I think I did take a quick look at them, but not enough to be able to post about them.) This message was modified Dec 3, 2009 by jimsocal
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Jim I just know the information I posted has helped me to better understand what is actually going on with my purchase of a latex mattress. For instance the new firm blended piece of latex I just received from FlowBeds feels no firmer to me than my medium piece of natural latex. Come to find out it has a lower density than the natural. This is all completely explained in the PDF's that I posted. I agree with you that there is nothing like trying something out to really know what's going on. You can have all the knowledge in the world and it is not going to help you unless the people you're purchasing from have the same knowledge and are honest about their products so that you can make an informed decision. But armed with this knowledge you're in a much better position to understand what is going on when you do get their product. One of the things that they talk about rather extensively in the information I posted, was how less dense foam can break down. I was not aware of the fact that manufacturers are able to produce foam that has a high density and therefore support qualities yet is soft to the feel. And conversely can produce low-density foam that is quite firm feeling but has poor support qualitys thus having the potential to "bottom out" and experience premature fatigue IE, body impressions and rutting. Since I have searched and searched for this kind of information on the Internet, and had been unable to find it, I thought that this discovery might prove helpful to some of the board members. This message was modified Dec 4, 2009 by eagle2
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Eagle, it would be interesting if you could compare the XF blended to the F 100% natural. |