Latex - Maximum/Highest Firmness or Indentation Load Deflection (ILD) for Dunlop

[phoenix]

Hi aldaarias,

Phoenix, thank you so very much for your speedy and detailed response, so appreciated.

You’re welcome!

I previously had a cheap and too soft coil and poly foam mattress from Ikea and I believe that’s where my issues stem from. My husband and I are petite people; I am 5’3" tall, 130 lbs and a BMI of 23.0, my husband is 5’6", 146 lbs with a BMI of 23.6. I have a herniated disk at L1/S1, so yes lower back problem indeed. We definitively prefer firm sleeping surfaces and sleep in all positions.

I’m sorry to learn about your low back issues. But it seems that you certainly prefer a firmer sleeping surface, as what you have right now is generally considered quite firm.

The first seller states on their site their GOLS organic Dunlop is sourced from ARPICO in Sri Lanka. The second seller states their 100% natural latex is sourced from Lien A in Vietnam. The first seller says their layer has 90 density. The second seller says the layers I’m considering have a 5.9 and 6.0 density respectively. How can I use these numbers for an apples to apples comparison of the higher firmness I’m looking for? Could the Lien A latex contain additives to get to the higher ILD?

As I commented previously, the density will be the more reliable comparison between two Dunlop layers, and the ILD isn’t quite as accurate unless a specific core of foam has been tested. Overall, the hardness of the latex can be influenced by such factors as the density, type and mix of the latex, fillers, method of vulcanization, and the size and distribution of the pin-holes.

Most Dunlop manufacturers test ILD using a 6" core. The ILD rating is then taken at either a 25% compression or at a 40% compression. The most common measurement for cores in North America is 25%. If the core is 6" then 25% would be 1.5", and 40% compression would be 2.4". So the 40% ILD number would be higher than the 25% ILD number for the same latex. With Dunlop, some ILDs are estimated via formulas the manufactures have set up. Others are actual measurements.

In some charts I have for Arpico (I’m not sure of the actual blend of Dunlop), they list “possible” ILDs for their 85 (+/-5) kg/M3 in the 31-36 ILD range (at 40% compression). At 95 (+/- 5) kg/M3, they list the possible ILD range as 39-45 ILD.

The numbers you were given for Lien A are in lb/ft3, so the 6 would translate roughly to a 95 kg/M3 density. This is sometimes termed an XX Firm, and in the attached chart you can see it rates as an approximate 46 ILD, but I’m not sure of the compression of this (25% or 40%).

There’s another chart I have (see attached) of common Dunlop ratings from around the world, and in this chart (at 40% compression), there is a representation of Dunlop in the 95-100 kg/M3 range listed with an approximate ILD of 59-66, of which the 63 ILD you are being quoted would fall right in the middle.

All of this goes to show you that ILDs are not quite as clear-cut a manner to compare Dunlop latex, and while the different piece of latex you’re considering should be firmer than your current product, I don’t think the difference will be as dramatic as the ILDs have been represented to you, for the reasons in ILD representation as I’ve described.

Maybe a zoned core would be best for us. Would you know which TMU sellers stock GOLS organic Dunlop zoned cores in the US?

As for site members who sell zoned latex cores, you may wish to investigate:
Arizona Premium
FloBeds has a very unique zoned system
SleepEZ may be able to procure a zoned Dunlop core for you, but you’d have to phone them

Most people that are looking for an “organic” mattress or materials are usually concerned more with “safety” than whether the materials have an actual organic certification and they usually aren’t aware that an organic certification isn’t the same thing as a safety certification. There is more information about the three different levels of organic certifications in post #2 here and some of the benefits of an organic certification in post #3 here and there is more about the different types of organic and safety certifications such as Oeko-tex, Eco-Institut, Greenguard Gold, C2C, and CertiPUR-US in post #2 here and more about some of the differences between organic and safety certifications in post #2 here and there are also some comments in post #42 here that can help you decide whether an organic certification is important to you for environmental, social, or personal reasons or whether a “safety” certification is enough.

Phoenix