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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Good question BeddyBye, and one I have been wondering about myself. I'm sure they do feel different, even if they are the same IFD. I think we might gain some insight if we also knew the 65% IFD rating for each foam, which in turn would give us the "support factor" (also known as "deep down support") for each of the foams. Resiliency (measured by the ball rebound test) is something else that will affect the feel, but alas, we don't know those numbers either. I have been trying to understand this mystery of why some people just can't seem to get happy with latex. The numbers all say latex should be the ultimate mattress material, numerically superior to nearly any polyurethane foam in pretty much every category. And yet, some people just can't do latex. It's a mystery. I have been entertaining the idea of using a layer of 3.0 lb HR foam of something North of an ILD 44 for the bottom layer of my mattress. The price is reasonable, and a foam of this density should last for 10 years without significant degradation. This message was modified Sep 20, 2007 by haysdb
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Re: Latex ILDs compared to High Resilience PU foam firmness
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Where do you think you might purchase the HR foam? If my mattress guy can't sell it to me for a price I feel is reasonable, then I plan to buy it online IF I decide to use all PU foam and nix the latex for now. All I would need is one more 45 and 55. (The 55 is light yellow and the 45 is a turquoise type of blue.). I wonder if it's always sold in those colors to differentiate the IFD. Anyway;I can buy up to 1" thick in order for three of the layers to fit inside my mattress over the coils. The other two are 3/4"; thick. I might just do that if this new configuration I just created doesn't work. I'm hoping with the 44 ILD latex sandwiched in between the two PU layers, I won't feel the latex against my back as much. We'll see! I did put a fiber topper called the Cuddle Bed on top to soften it up a bit.<BR><BR><BR> haysdb wrote: Good question BeddyBye, and one I have been wondering about myself. I'm sure they do feel different, even if they are the same IFD. I think we might gain some insight if we also knew the 65% IFD rating for each foam, which in turn would give us the &amp;amp;quot;support factor&amp;amp;quot; (also known as &amp;amp;quot;deep down support&amp;amp;quot;) for each of the foams. Resiliency (measured by the ball rebound test) is something else that will affect the feel, but alas, we don't know those numbers either.&amp;amp;amp;lt;BR&amp;amp;amp;gt;&amp;amp;amp;lt;BR&amp;amp;amp;gt;I have been trying to understand this mystery of why some people just can't seem to get happy with latex. The numbers all say latex should be the ultimate mattress material, numerically superior to nearly any polyurethane foam in pretty much every category. And yet, some people just can't do latex. It's a mystery.&amp;amp;amp;lt;BR&amp;amp;amp;gt;&amp;amp;amp;lt;BR&amp;amp;amp;gt;I have been entertaining the idea of using a layer of 3.0 lb HR foam of something North of an ILD 44 for the bottom layer of my mattress. The price is reasonable, and a foam of this density should last for 10 years without significant degradation. This message was modified Sep 21, 2007 by BeddyBye
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Where to buy HR PU foam
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FoamOrder - Pelma Everflex V54, 3.2 lb, 45 ILD FoamOnline - 3.0 lb HR, 44 or 55 ILD Both offer it in whatever thickness you want, in one-inch increments from 2" to 8". |
Re: Where to buy HR PU foam
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Wow, that was fast! You must be out on the West coast like me! Thank you!<BR><BR> haysdb wrote: FoamOrder - Pelma Everflex V54, 3.2 lb, 45 ILD<BR><BR>FoamOnline - 3.0 lb HR, 44 or 55 ILD<BR><BR>Both offer it in whatever thickness you want, in one-inch increments from 2" to 8". |
Re: Latex ILDs compared to High Resilience PU foam firmness
| Many of the upholstery supply sites have HR foam. I bought some pieces from rockfordsupply.com to use in one of my experiments. The price of the foam was reasonable; the shipping charges were not. You might get some ideas by looking at this page, even though they don't seem to have the ILD you are looking for. http://www.rochfordsupply.com/buyersguide_foam.asp |
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. |
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. |
Re: Latex ILDs compared to High Resilience PU foam firmness
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This will be considered blasphemy by many or even most on this forum, but I am considering using a layer of firm HR foam to add some support to my latex core without spending $900 on another core. It was actually a guy at a custom mattress place who suggested it. The suggestion was for 1" of IFD 44 HR or even 55 foam placed between my two layers of 38. This seems worth a try. HR foam with a density in the vicinity of 3.0 lb should hold up for a good long time. Folks around here love their latex, and for good reason, but let's be honest, firm support isn't latex forte. I do think I would have been fine had I bought the ILD 44 core instead of the 40 (which came in on the soft side), but that's not an option for me now. |
Re: Latex ILDs compared to High Resilience PU foam firmness
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BeddyBye, I saw this post after responding to your Bonnell Coil thread, and now I REALLY think the latex is part of the problem. Latex will compress. It's very squishy even at high ILDs, but when you get off of it it pops right back up. That's why you can't actually see any sagging when you open your mattress. It's not sagging. It's compressing under your weight and pushing back against your body at the same time. The HR foam on your husband's side has completely different properties. It's passive rather than active. It's firm but it doesn't push back. My experience with it is that even at the same ILD it doesn't even seem to compress very much at all when you lie on it. But that might be because it actually is firmer than latex of the same ILD, as Haysdb's input indicated. Personally I find it much more comfortable than latex. I guess you've come to the same conclusion I have about the latex. It's not a good match for your back. I also think that 45 is too firm to qualify as a "comfort" layer over coils. I hesitate to suggest that if you really like the feeling of latex you try no more than an inch and a half of 32 ILD, because you're already having a hard time with latex. After six weeks of torture on a latex mattress I'm kind of wary of the stuff. I like memory foam as a comfort layer because it's completely passive and very good at pressure relief, but that's just me. |
Re: Latex ILDs compared to High Resilience PU foam firmness
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If you can find high density foam, whether it is polyurethane, latex, memory foam, or whatever, it should have a good lifespan. My Grandma has a sofa which has been in use for decades and shows no signs of wear. I would like to dissect it to find out what kind of foam is inside. Just from sitting on it, it feels like high ILD polyurethane. I am guessing it is also high density. I also don't understand why people here are so infatuated with latex. I think the scorn for PU foam was created by the S companies use of low density PU foam that failed quickly for many of the members here. If it is light in weight, expect failure soon. If it feels very heavy for it's size, expect it to last a while. Of course there are exceptions (like Resilitex). |
Re: Latex ILDs compared to High Resilience PU foam firmness
| I would be interested in knowing what is in that couch also. I visited two custom mattress factories yesterday and one commented that quality PU foam showed up on the market 12-13 years ago. He didn't elaborate. I don't know what the state of the art in PU foam was 20+ years ago, but I know that predates high resiliency and high density foams. |
Re: Latex ILDs compared to High Resilience PU foam firmness
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haysdb wrote: This will be considered blasphemy by many or even most on this forum, but I am considering using a layer of firm HR foam to add some support to my latex core without spending $900 on another core. It was actually a guy at a custom mattress place who suggested it. The suggestion was for 1" of IFD 44 HR or even 55 foam placed between my two layers of 38. This seems worth a try. HR foam with a density in the vicinity of 3.0 lb should hold up for a good long time. Folks around here love their latex, and for good reason, but let's be honest, firm support isn't latex forte. I do think I would have been fine had I bought the ILD 44 core instead of the 40 (which came in on the soft side), but that's not an option for me now.
One problem people can suffer from in the search for the perfect component combination is hypersensitivity/princess-and-the-pea syndrome. During my search I suffered this affliction but I've long since gotten past that and now I just sleep without any analysis. Good luck in your search. This message was modified Sep 26, 2007 by kbell
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Re: Latex ILDs compared to High Resilience PU foam firmness
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Something I find interesting is that IFD's of Polyurethane foam take bigger jumps than latex. PU goes from , for example, 33 to 44 to 55 to 77. I have inquiries into several places, including the Polyurethane Foam Association and "the foam guy" from a local custom mattress maker, to see if I can gain some understanding of why PU foam might be "firmer" than latex for a given IFD. One problem with mixing latex and PU foam is that people tend to prefer latex OR polyurethane foam, including memory foam. There just isn't much information out there about mixing the different foams. I occasionally read a comment from someone saying not to mix the different foams, but without any particular explanation for why they think it's not a good idea. Can anyone shed any light on that? |
Re: Latex ILDs compared to High Resilience PU foam firmness
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haysdb wrote: Something I find interesting is that IFD's of Polyurethane foam take bigger jumps than latex. PU goes from , for example, 33 to 44 to 55 to 77.</p><p>I have inquiries into several places, including the Polyurethane Foam Association and "the foam guy" from a local custom mattress maker, to see if I can gain some understanding of why PU foam might be "firmer" than latex for a given IFD. One problem with mixing latex and PU foam is that people tend to prefer latex OR polyurethane foam, including memory foam. There just isn't much information out there about mixing the different foams. I occasionally read a comment from someone saying not to mix the different foams, but without any particular explanation for why they think it's not a good idea. Can anyone shed any light on that? Heck, I have all three in my mattress. PU, latex and some memory foam. Now we'll see how they work together to make my back feel good! I may just have to go to all cotton if I can't come up with a solution soon! |
Re: Latex ILDs compared to High Resilience PU foam firmness
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I submitted the following question to the Polyurethane Foam Association: Are the IFDs of flexible polyurethane and latex measured the same way? A foam supplier has told me that an HR foam with an IFD of 34 will be about equivalent in firmness to an IFD 44 talalay latex. He says it relates to density, but pfa.org documents are explicit that IFD is not related to density. http://www.pfa.org/jifsg/jifsgs1.html It can't be related to resilience or support factor because latex will typically be at least as good as a PU foam in these two areas. Their reply... [1] IFD is measured the same way for both products. Many latex foam rubber products have greater compression modulus than conventional foam and HR foam products. In common terms, that's Support Factor. Here's what it means: IFD at 25% is a measured resistance to compression force. You could specify an HR foam with a 45 lbs IFD at 25% compression and essentially it would be equal to a latex product with an IFD of 44 lbs at 25% deflection IN TERMS OF SURFACE FIRMNESS. If you were then to measure the IFD at 65% compression, theoretically, the latex sample would have a higher number (greater support). Bob Luedeka Executive Director In other words, the ILD 44 latex should be MORE supportive than the 44 HR since it will have the same 25% ILD, and therefore the same surface firmness, but a higher 65% ILD, and therefore a better compression modulus or "support factor," for superior deep down support. I have also asked this question of Dewey at FloBeds. He didn't know the answer but was going to talk to his foam guy whom he says has a good feel for the equivalencies of the two foams. I am going to "get to the bottom of this" if it's humanly possible. [1] The forum rules specify that we can't quote emails, but this is purely informational and not personal in nature. This would seem to be in keeping with the "spirit" of the rules, if not the letter. This message was modified Sep 28, 2007 by haysdb
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Re: Latex ILDs compared to High Resilience PU foam firmness
I received samples of three different ILDs of 3.0 lb HR foam today from FoamOnline.
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