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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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. |
Re: Latex ILDs compared to High Resilience PU foam firmness
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Wow. I have 55 and 45 PU foam in 3/4" thick. If that's the case, they would be as LOT firmer than my 44 ILD talalay latex layer of 1". That just doesn't seem right. I can honestly say that I don't feel that big of a difference in firmness.<BR><BR><BR> haysdb wrote: I sent an email inquiry to FoamOnline.com asking about their HR foam:<BR><BR><div style="margin-left: 40px;"><span style="font-style: italic;">We manufacture custom cuts on high resilience foam and supply it in a ILD</span><br style="font-style: italic;"><span style="font-style: italic;">34 which is compareable to the talalay latex ILD 44. We also offer a ILD</span><br style="font-style: italic;"><span style="font-style: italic;">45 which is firmer. The reason the numbers seem out of order is because</span><br style="font-style: italic;"><span style="font-style: italic;">the latex ILD numbers are softer than most other foam products. High</span><br style="font-style: italic;"><span style="font-style: italic;">resilience ILD numbers are firmer than most other foam products. You may</span><br style="font-style: italic;"><span style="font-style: italic;">price quote or order any foam from us simply by clicking on to the cube</span><br style="font-style: italic;"><span style="font-style: italic;">shape in the upper left hand corner of our homepage.</span><br style="font-style: italic;"><br style="font-style: italic;"><span style="font-style: italic;">Thank You,</span><br style="font-style: italic;"><span style="font-style: italic;">foamonline.com</span><BR></div><BR><BR>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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I stopped by a small custom mattress maker after work tonight. They had some foam samples of PU foam and talalay latex and the PU felt a LOT firmer than the same IFD latex. This really has my interest now. Why would this be so? Here is an email exchange I have had with one of the foam companies Them We manufacture custom cuts on high resilience foam and supply it in a ILD 34 which is comparable 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. Me ...what makes you say an HR IFD of 34 is equal to a latex 44? Are the tests performed differently? For example, is latex measured with a 5.6" or 6" sample rather than a 4" sample? I have read in PFA documents that IFD increases with thicknesses, which is why the standard specifies a 4" thick sample. Does it have to do with different "support factors", or resiliency, or what? Them The difference is the density or weight per cubic ft. of a particular foam type. The 3.0 lb ILD #34 HR vs. 5.6 lb ILD #44 latex. The tests are performed identical with different results due to density. Your correct firmness does increase with thickness. Different results due to density? But the Flexible Polyurethane Foam Association says density is not related to IFD: 1.1. Density continues to be one of the most misunderstood properties of polyurethane foams. Some people mentally relate density to the firmness of foams, and that relationship is totally incorrect. Foams with an extremely wide range of hardness can be made at an extremely wide range of densities. DENSITY STANDARDS AND GUIDELINES 25% IFD (indentation load deflection, see chapter 4) is a measure of the hardness of foams; and for example, a 20 pound/50 in2 IFD can be made at densities ranging from 1.0 PCF (pounds per cubic foot) to 10 PCF. The key is that density is in no way related to IFD. |