I apologize, as I know the “Natural vs Blended” question has been heavily tread, however, the threads I’ve read focused on durability questions, while I’m looking to know about the difference in compression modulus, particularly in the 6" core support layer.
I’m a heavy guy (315 lbs, slowly losing weight, ~25 lbs a year) and the affordably available 6" cores (specifically Latexco Dunlop) seem to top out at 36 ILD, which I suspect may be a little on the soft side for my current weight.
If I understand compression modulus and ILD ratings correctly; at the same ILD, the lower modulus blended would ‘start’ firmer than the higher modulus natural, but fall behind as the piece was compressed further.
Essentially, firmer if compressed by less than 25%, equal if compressed 25%, and softer if compressed by more than 25%.
My questions are thus;
1: Am I likely to compress the core support layer by more or less than 25% enough for the difference to appear at all?
2: If #1 is yes, is this difference substantial enough to become a support effectiveness concern? The responses I’ve seen say “most people aren’t likely to notice” but with my weight being well above “most”, I’d like to be sure.
Welcome to the TMU Forum ! Thanks for your question.
Great work on your DIY project, Asbrandt! Sounds like you have a good understanding of your personal preferences and are narrowing down on materials of interest and layering. From your other post #1 “Seeking Advice on DIY Build”, I see that you received sound guidance from Expert member @KenHightower/ Arizona Premium Mattress. Ken has a deep understanding of latex components and attributes, as well as many years’ experience designing quality products based on consumer preferences; I think highly of his advise.
I dropped by AZ Premium’s site to review the Latexco 6" All Natural Dunlop Latex Solid Core (I’m guessing that is where you are considering a purchase?) and confirmed product specs indeed top out at 36 ILD. Just curious: as Ken previously suggested “For the base I would go with Dunlop firm in the 35-39 D-85 range”, he likely would have a means for sourcing that. Is this particular Latexco core one you both discussed as an option?
[quote]If I understand compression modulus and ILD ratings correctly; at the same ILD, the lower modulus blended would ‘start’ firmer than the higher modulus natural, but fall behind as the piece was compressed further. Essentially, firmer if compressed by less than 25%, equal if compressed 25%, and softer if compressed by more than 25%.
[/quote]
One of Latex’s greatest advantages lies in its level of firmness (ILD)/ support factor, also known as compression modulus. For those following your research, Phoenix’s article “Mattress Support Cores- Latex” is an excellent read for learning more Latex’s inherent advantages over other support core materials. Also in keeping with thoughts from Phoenix’s post #7 “Denver Mattress Snowmass vs Ultimate Dreams”: “The biggest difference between Talalay latex vs dunlop) is what is called compression modulus. This is a measure of how quickly a foam gets firmer as it is compressed more. ILD is generally (but not always) a measure of how much weight it takes to compress a foam by 25% of it’s thickness. At compression depths less than this Dunlop will be softer (compress more with the same weight) while at compression depths more than this Dunlop will be firmer (compress less with the same weight). They have a different response curve in other words and since Dunlop gets firmer faster than Talalay … even though the different response curves may cross at the 25% compression level … beyond this Dunlop will not compress as much as Talalay which is why it is generally considered more supportive or “firmer”. Another way to say this is that Dunlop starts off softer and then ends up (at compression levels more than 25%) firmer than Talalay.”
[quote]My questions are thus;
1: Am I likely to compress the core support layer by more or less than 25% enough for the difference to appear at all?
2: If #1 is yes, is this difference substantial enough to become a support effectiveness concern? The responses I’ve seen say “most people aren’t likely to notice” but with my weight being well above “most”, I’d like to be sure.[/quote]
You will “feel” more of the upper comfort layers than the deeper support layers when you first lie on a mattress. Your own experience is the only way to know which “feel” you prefer with any certainty. Again, I will defer to our expert members suggestions as they are the “best” expert on the feel and performance of their mattresses and on which is the best match for the different body types and sleeping positions of different people.
Looking forward to hearing which way you decide… .
Thank you, and yes I did consult Ken first as I intend to purchase from one of his sites, but I think he skim read over the part in my second post where I asked about compression modulus, I get the impression he’s busy.
By my understanding, a given ILD rating is really about in the middle of a range of ILD values because the Dunlop process isn’t precise in its resulting ILD, so I assumed that “35-39 D-85” was the real value range of a piece rated as 36 ILD.
Posts by Phoenix on the subject of Natural vs Blended mentioned that Synthetic (and by extension, Blended) Latexes would also have a lower modulus than the equivalent natural, but I didn’t have a sense for how that quantifies compared to the difference in modulus between Dunlop vs Talalay, hence the posting of this thread.
That’s the tricky part, as I mentioned in the thread with Ken, I’ve tried some mattresses and found that I am not picky and don’t have “immediate” comfort issues, so I’m looking at possible differences of overnight support effectiveness, wanting to cover all my bases before I proceed.
! Thanks for your question.
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