TOPIC:

I've been searching for hours and so far have come up dry. Dunlop processed latex is inherently less uniform, denser on the bottom due to settling during the process and so provides a sort of integral layered property of softer on top, firmer on bottom. Is this for all dunlop process? (molded, not continuous pour variety). Or does this tend to hold more true of natural and less true of synthetic? Also, I've been trying to find out if there's any 'rough' estimation of the firmness difference from top to bottom.

For instance, it's accepted that talalay has a sag factor of around 3 associated with it. Dunlop has a sag factor of around 4 associated with it. Is there someplace I can find that would have this info? Such as 'dunlop being denser on the bottom than on the top, this equates to roughly a 10% or 20% difference between the top of a core and the bottom'? Something along the lines of typically, the bottom surface of a 6" core will be x amount firmer than the top.

Also, is the tendency to be firmer on the bottom half more related to natural than it would to something more consistent like sbr? Or does it have more to do with the dunlop process itself (ie, regardless of natural or sbr, the dunlop method always has more density along the bottom).

My reason for asking is I'm considering a 6" blended dunlop core that's 80/20 (mostly synthetic). Being that most of it is synthetic material, will there still be that density variation providing me some benefit in being able to flip the core soft side down if I need it more firm (similar to swapping a firm/med pair of 3" layers).. or has that benefit been decreased substantially due to the high amount of sbr? The price on the single core is attractive, but if there won't be much difference achieved from flipping it should I want to try a different configuration, I might be better off with 2 3" layers. I'm sure it's only a minor difference flipping a 6" core. Guessing in the dark here, but I imagine if it's 36 ild on top of the soft side, a 6" core would feel similar to 3" 36 over maybe 3" 40 ild on bottom. If a bigger variation was needed, it would take 2 3" layers with a wider difference, correct?

If the answer is yes, all dunlop (hopefully blended being more similar to natural than all synthetic) by nature is denser/firmer on it's lower half, then a 6" core would provide me with at least some noticeable adjustment by flipping it. If the answer is no, being 80% synthetic it will be more consistent and lose much of that density/firmness difference top to bottom that dunlop is known for, then it won't give me much wiggle room to make any adjustment by flipping it. Obviously 2 3" pieces of say 36 and 44 would give me much more clear cut firmness adjustments (and be much easier to handle) but it's also much more costly. I just don't want to be suckered in by a good price only to find out that flipping that particular blend makes hardly any difference (more like talalay, where if you flip 36 ild any which way it's all the same just a thicker piece).

Thanks

Hi brass,

I've been searching for hours and so far have come up dry. Dunlop processed latex is inherently less uniform, denser on the bottom due to settling during the process and so provides a sort of integral layered property of softer on top, firmer on bottom. Is this for all dunlop process? (molded, not continuous pour variety). Or does this tend to hold more true of natural and less true of synthetic? Also, I've been trying to find out if there's any 'rough' estimation of the firmness difference from top to bottom.

This would be more true for molded Dunlop than continuous pour Dunlop and there is also a wide range of differences between individual cores. For example some pincores are telescoping so they can be larger in the deeper parts and thinner in the upper parts to help compensate for the differences between the top and bottom of the core. I haven't seen any specific information that talks about the actual difference in terms of ILD on a manufacturer by manufacturer basis but I do know that in most cases it's fairly noticeable with molded Dunlop. Some manufacturers for example that slit a 6" core into two 3" layers themselves will have to assess and "rate" the top and bottom layer individually because the difference between them can be significant enough to "rate" them differently.

For instance, it's accepted that talalay has a sag factor of around 3 associated with it. Dunlop has a sag factor of around 4 associated with it. Is there someplace I can find that would have this info?

The only place I know that would provide this would be a specific manufacturer if they were willing to disclose these types of specs for each of their materials which isn't likely. For most people it would be meaningless anyway because there are so many other specs that affect the feel and performance of a mattress that any one of them by themselves would say little and a combination of all of them would be overwhelming to most people if they were to try and use them as a way to choose a mattress or a material outside of more generalized information. This would be a good subject for a PHD thesis but is much to involved to have any practical use in "real life".

Also, is the tendency to be firmer on the bottom half more related to natural than it would to something more consistent like sbr? Or does it have more to do with the dunlop process itself (ie, regardless of natural or sbr, the dunlop method always has more density along the bottom).

It's related to both. Dunlop isn't "flash frozen" like Talalay and natural latex has a wider range of particle sizes and is usually less consistent and can stick together more than synthetic latex.

My reason for asking is I'm considering a 6" blended dunlop core that's 80/20 (mostly synthetic). Being that most of it is synthetic material, will there still be that density variation providing me some benefit in being able to flip the core soft side down if I need it more firm (similar to swapping a firm/med pair of 3" layers)

I don't know the specifics of the top and bottom differential of particular manufacturers or blends of Dunlop (they don't provide this information and I haven't seen it anywhere) except to say that it's likely that there would be "some" difference. If it's molded Dunlop there would likely be "enough" difference that you would feel it even with a mostly synthetic blend but I don't know enough to attach a number to it and the same number may not be accurate for other manufacturers.

When you are looking at this type of overwhelmingly complex technical information the "experiential" knowledge of a manufacturer or supplier about the materials they sell would probably be a more accurate source of information than trying to find out and then "translate" these types of very complex combinations of material specs.

Phoenix

Hi Phoenix, thanks for the prompt reply. I was hoping the answer would be simpler, maybe there was some sort of correlation like on average, a 10-15% firmness difference or something like that. Seems I never have simple questions On the bright side at least there's some notable difference. I just didn't want to opt for a solid core and find out there was so little difference it wouldn't matter (similar to flipping talalay, it doesn't matter what side it's on) and end up shooting myself in the foot. Find out later that this would have been a feature of the dunlop only if I'd gone 100% natural, but because it was a mostly synthetic blend I should have opted for 2 varied 3" pieces.

The core I found isn't labeled, but if I had to guess I'm assuming it's a Latexco. Tri-zone 5.5", 32-36-32 ild, 80/20 blend, almost identical to the one offered at mattresses.net. However they list theirs for around $400 for a full/dbl plus a fairly hefty shipping fee that's a little over $100. This other one I found is $340 plus $12 shipping so it may be worth taking a chance.

After doing some more checking around, I found a place called STLbeds not too far from me in the city about 45min away that has savvyrest models so I'm planning to get up there and check them out to get a better feel for the differences in firmness and types of latex. Hopefully can make that trip in the next few days or so. On the bright side, if for some odd reason it turns out I can't find comfort with latex (I doubt that) and need to go back to considering innerspring, the same place also deals in 2 sided mattresses and share similar thoughts about the "S" brands (avoid them, lol). So it looks like they have some more useful insight than most of the outlets around me.

Thanks again Phoenix

Hi brass,

After doing some more checking around, I found a place called STLbeds not too far from me in the city about 45min away that has savvyrest models so I'm planning to get up there and check them out to get a better feel for the differences in firmness and types of latex. Hopefully can make that trip in the next few days or so.

You've probably seen this already but STLBeds is one of the better "options or possibilities" that are included in the St Louis list here .

Phoenix