Latex ILDs compared to High Resilience PU foam firmness
| I'm pretty sure my mattress maker told me that the one inch 44 ILD talalay latex layer and the 45 HR high density PU foam 3/4" were very close in firmness. But wouldn't they still have a different sensation? Latex being more bouncy and firm PU being less so.<BR><BR>I think I've just about given up trying to make my latex layers (only 2 inches) work for me. I couldn't figure out why husband's side of the bed felt firmer than mine. I swear mine seems to compress throughout the night and yet when I open my mattress I don't see any sagging or compressions. That includes the coils. But my husband's side didn't seem to be quite that way. Well, I opened his up and found NO latex inside! I had forgotten that I took the two 44 ILD layers and one 45 ID PU foam. He, on the other hand, had three layers of PU foam. 55, 45 and 45. Coils, too. No wonder if was firmer!<BR><BR>So, I kept the 55 PU foam in both of our mattresses and sandwiched the 44 ILD between the 45 PU foam. The 55 is the base over the coils ending up with the highest layer the 45 PU foam. We shall see how it works tonight! If my back is still sore, I plan to order two more layers of HR PU foam in 45 and 55 and we can both forget the latex! I'll keep it around just in case. <BR><BR>I really am beginning to wonder if my back and latex make a good match. I'm doubting it. |
Re: Latex ILDs compared to High Resilience PU foam firmness
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Maybe I could talk Dewey into sending me a set of latex samples, and then dig up some samples of HR foam somewhere. I would like to get some sense of how the different foams "feel". It's just one of those "inquiring minds want to know" things for me. I did some searches to see if I could find some beds made with super firm HR foam, and didn't really find much except that some of the ILD 50 and 55 stuff is used for a "deep down support" bottom layer. I do question how PU foams can be any more supportive than latex (for equal ILD), just based on the numbers for density and "support factor". Latex is a 4.4 to 5 lb density, with a support factor of 2.5, 2.6, somewhere in there. Even the high quality PU foams are 3.0 to 3.2 lb, with support factors 2.2-2.4. And keep in mind, not many mattresses are being made with this quality of PU foam. This is a "premium quality PU," which is somewhat of an oxymoron. Latex can be soft and yet has a "deep down support" that typical PU foams can't match. Something interesting in the way of psychology is that my first impression of my ILD 38 core was that it was "too soft." But after a few days, when I lay down on it now, it feels very firm. What happened? Dewey at FloBeds told me that most of his customers have the same initial reaction: "it's too soft," but it's just the different feel of latex vs. an innerspring mattress. Something else interesting is that 3 layers of the 38 feels firmer than 2. I think this comes back to something I read about ILD testing, that thicker samples will have a higher 25% ILD. A 5.6" core will have a higher ILD at 25% than would a 4" thickness of the same material. |
Re: Latex ILDs compared to High Resilience PU foam firmness
| I don't know why my lower back is suddenly starting to hurt again. It's not just sporadic anymore. It started after we got back from a 2 night trip to Mendocino. We slept on regular mattresses (no latex). One was very comfortable. The other not as much so. But, now ever since then my mattress at home has caused my lower back to hurt. I've tried tweaking the layers to no avail. I'm going to take out my last latex layer and see if that helps. I do have a fiber topper which is sooooo comfortable. I sure hope I won't have to take that off! It's only been there a few days, but the back pain started long before. Gee, all I want is a painless night of sleep! I'm hoping 3 layers of high density PU foam over the medium support LuraFlex coils will work. If not, I'm at a loss. I can't afford another mattress, especially if I have no guarantee that's even the main problem. <BR><BR>Do you think sitting at the computer for hours can cause lower back pain? Am I blaming my bed when it's really SITTING that is causing the problem??? Hmmmmm.... |
Re: Latex ILDs compared to High Resilience PU foam firmness
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I think the two are related, but a mattress should allow your back to recover during the night, not make it hurt. I have heard it said that if your back hurts, blame you back, not the mattress, but that's a cop-out on the part of the mattress industry IMO. There is a reason chiropractors recommend some mattresses and not others. It seems to me that you would only want maybe 4" of foam over a set of coils. I have nothing to back that up, it's just "intuitive". More than that and the springs can't do their job very well. I'm going to see about getting some samples of HR foam. |
Re: Latex ILDs compared to High Resilience PU foam firmness--to haysdb
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haysdb wrote: I think the two are related, but a mattress should allow your back to recover during the night, not make it hurt. I have heard it said that if your back hurts, blame you back, not the mattress, but that's a cop-out on the part of the mattress industry IMO. There is a reason chiropractors recommend some mattresses and not others.<BR><BR>It seems to me that you would only want maybe 4" of foam over a set of coils. I have nothing to back that up, it's just "intuitive". More than that and the springs can't do their job very well.<BR><BR>I'm going to see about getting some samples of HR foam. <BR><BR>Besides the coils, I have only 2 and 3/4 inches of HR PU/latex. Then the lightly quilted cover. So, the coils are definitely doing their job...I hope! I agree that someone's back shouldn't hurt as a result of sleeping on a particular matttress, unless it's hopelessly sagging or not doing its job anymore. Mine isn't quite a year old and I have quality interchangeable "parts", and that includes the zippered cover. So, I know it has something to do with the configuration of this mattress. I'm starting a new thread regarding innerspring coils and something that I'm going to experiment with starting tonight. That might be my answer right there.... |
Re: Latex ILDs compared to High Resilience PU foam firmness
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Does your HR PU foam feel softer in the middle than at the edges? If so, it is shot. That could be stressing out your back. Foam (or any mattress material) should feel consistent in firmness from edge to center and to the next edge. Even if a crater is not seen, if softness can be felt, the material is shot. This message was modified Sep 23, 2007 by MequonJim
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Re: Latex ILDs compared to High Resilience PU foam firmness
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No, it's firm all the way through. It's less than a year old and HR with high IFDs. My mattress person showed me some examples of crummy PU and compared it to what he uses in his mattresses. He's not big on gimmicks or even convoluted foam. I have two 3/4 layers of solid, firm PU foam in there and it sure better not be shot after less than a year! He said HR foam like this shouldl last a good 10 years. He has a warranty of 20 years on the mattress, itself. And, if it shows compressions at an inch, he'll exchange it or whatever necessary to make it better.<BR><BR><BR> MequonJim wrote: Does your HR PU foam feel softer in the middle than at the edges?&nbsp; If so, it is shot.&nbsp; That could be stressing out your back.&nbsp; Foam (or any mattress material) should feel consistent in firmness from edge to center and to the next edge.&nbsp; Even if a crater is not seen, if&nbsp;softness can be felt, the material is shot. |
Re: Latex ILDs compared to High Resilience PU foam firmness
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I do think people need to differentiate between high quality HR (high resilience) polyurethane and the 1.6 and 1.8 lb density garbage. This message was modified Sep 23, 2007 by haysdb
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Re: Latex ILDs compared to High Resilience PU foam firmness
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So do I. There really is a difference. <BR><BR><BR> haysdb wrote: I do think people need to differentiate between high quality HR (high resilience) polyurethane and the 1.6 and 1.8 lb density garbage. |
Re: Latex ILDs compared to High Resilience PU foam firmness
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I sent an email inquiry to FoamOnline.com asking about their HR foam: We manufacture custom cuts on high resilience foam and supply it in a ILD 34 which is compareable to the talalay latex ILD 44. We also offer a ILD 45 which is firmer. The reason the numbers seem out of order is because the latex ILD numbers are softer than most other foam products. High resilience ILD numbers are firmer than most other foam products. You may price quote or order any foam from us simply by clicking on to the cube shape in the upper left hand corner of our homepage. Thank You, foamonline.com This is interesting but I don't understand. 25% IFD is an industry standard measure. How can you say that a 34 IFD of one foam is equivalent to a 44 IFD of another foam? I'm not saying they are wrong, and it certainly would explain why some people just can't seem to get the support they need with latex, I'm just saying I don't understand. And if it's true, I think we need a translation table that equate's PU IFD's with latex IFD's. |
Re: Latex ILDs compared to High Resilience PU foam firmness
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The only "performance" measures I am familiar with in regard to foams are 25% IFD, 65% IFD, support factor (65% IFD / 25% IFD), resilience, and density. There are also durability tests. These are the only ones I have ever seen discussed in the Flexible Polyurethane Foam Association publications. Unless FoamOnline is claiming a higher support factor for their HR foam, or higher resilience, then their assertion that an HR foam is more firm for any given IFD is just hot air IMO. I'm keeping an open mind, I just need a plausable explanation for how this can be true. |