Mattress Forum

I have posted on this before. There is a difference between ILD and density. ILD is a measure of surface tension. Density is a measure of how much material is actually in the latex. ILD is measured by taking several readings at 25% of the depth of the piece of latex being tested. Density is measured by taking a reading at 65% of the material being tested, and dividing that by the 25% reading.

It is my understanding that Dunlop is a denser material than Talalay. This is why it feels so different. I have been told by those who claim to know such things, that you need to have a piece of Talalay that is at least one ILD rating higher than the Dunlop to have an equivalent support factor in the piece of latex.

Never having slept on Dunlop all I can do is relate the information I have.

I think the free shipping is only if you buy a whole mattress.   Hopefully they will give you a break on 1".  

When I talked to them once, I got the impression that they did not stock all of the different thicknesses, so they may have to special order for you.   Not sure how long that would take.  I guess you will have to call to asses the total situation.

Density is simply a measure of lbs per cubic foot, which is very difficult to measure with latex because of the holes in the product, it is a complex 3D shape in comparison to say a block of memory foam.  Realistically, I don't know how accurate what you have been told in the past is with regards to Talalay needing to be one ILD point higher than Dunlop to have a roughly equal firmness rating.....could be true, however an ILD difference of 1 is something that a human being simply could not feel in a blind comfort test, and again not every single piece of foam will actually have its ILD rating tested, so a 1 or 2 point variation is somewhat normal.  if you are buying a 22 ILD piece of latex it could be as low as 20 or as high as 24 ILD.

There are honestly way too many variables involved with latex to say 100% of the time that Dunlop is denser than Talalay, generally yes, but as with most things there are exceptions to the rule.  There are also different sub species to the rubber tree that can produce different qualities of latex, some seeds produce a more elastic rubber which for the same density rating as other latex would read higher on the ILD scale because it is more resilient.  So this way of measuring density would seem inaccurate because you cannot use the ILD rating as a factor in measuring density. 

Anyway I am getting way off topic, I will end my rant lol.

Poor Jim, this mattress tweaking is so tiresome(pun intended!).  Sometimes I have a hard time just remembering that a sore mid-lower back is from too soft foam(memory foam is an especially soft foam no matter what), hip and shoulder aches come from too firm foam, and neck ache comes from pillow issues.  Once we get to where we want to be, our brains let go of most of this info and we just want to stop futzing with the whole thing, LOL!!!
I think you are on the exact right track.  HR foam can give up, latex is probably the best bet.  I have not gotten any latex for my bed yet...still doing well with the bed as it came plus a polyfill topper.  Just try not to overthink it...simpler can be better...
Kait

budgy, you sound very knowledgeable about latex. Did you or do you work in the business?
Thanks for that info re Dunlop vs. Talalay.

yeah, my family runs a small independent store in Canada.  we specialize in latex products, thing is we are one of maybe 2 or 3 stores in North America I have been able to find that carry latex manufactured by most major manufacturers; latex international, dunlopillo (when they were still around), and latex green, as well as one smaller entity that actually owns their own latex plantation in malaysia.  its my job to sift through the BS that some manufacturers use to describe their product and learn what is truly accurate.  Even though we specialize in latex we seldomly even talk about the processes used (dunlop or talalay) as it is surprisingly unimportant in the greater scheme of things.  most talk about one process being better than another tends to stem from what product that company is selling rather than empirical evidence and un-biased analysis. 

Excellent info! Thanks.
So, if I can ask to help clarify:
For example, I once laid on some Dunlop latex and it seemed much more "dense" and others here in the past have noted that Dunlop latex tends to be denser, or feel denser, less spring-y, more of a "dead" feel as opposed to a bouncy feel. I know many including myself have had this impression and talked about it.

Are you saying this is just coincidence, that it depends on the maker, or batch, or something like that?
Or is our description "generally true" but not always true?
Or am I just plain wrong. (Nothing wrong with that, I'm willing to admit I might be wrong because I have very little experience with Dunlop latex.)

Your description is generally true but not always true.  I can think of a couple exceptions to the rule for sure. 

Thing is, there are many variables with latex much more so than Dunlop or Talalay process.  Especially since the words Talalay or Dunlop does not specify which material the latex is even made of. 

A list of the main variables in latex quality (not density):
1. What the latex is made of.
If the latex is all natural or even a partial blend the following will also play a role:
1. How much vulcanization and stabilization chemicals are used:
2.  How long the rubber is stored before being processed into a foam core.
3. Where the latex is grown (is it sourced from North Africa, or SE Asia, in particular your best latex comes from malaysia, but the rest of the good stuff from SE Asia)
4. What specific subspecies of tree the rubber is sourced from.
5. and finally the process will obviously matter, below I will explain why I list it so low on the hierarchy.

There are basically two substances that are considered latex.  Any plant milk which can be vulcanized into rubber, primarily the rubber tree would be the plant in question 99% of the time and 100% of the time with regards for latex in mattress use.  There is of course also synthetic rubber, made from petrochemicals it is called styrene butadiene.  You can make Dunlop or Talalay process rubber out of either 100% natural sourced latex or 100% petrochemicals.  With the same ILD rating, the performance of 100% synthetic vs 100% natural dunlop latex would be dramatically different.  You can also of course (and most commonly in North America) make latex using a blend of natural and synthetic rubber, typically 30% natural is the standard blend that latex international uses now-a-days and is the type of mixture you will see used in just about every mainstream companies beds.  They of course talk about the virtues of Talalay latex very commonly, which is the process they use for blended rubber. 

Interestingly enough even though you can make dunlop or talalay latex in any mixture of synthetic and natural rubber you can dream of you never see certain things too often.  primarily, you will almost NEVER see or find a manufacturer that uses Dunlop process for blended latex (synthetic and natural).  Most dunlop latex on the market will either be 100% synthetic (some cheaper Ikea mattresses) or 100% natural rubber (if you look at high end organic mattresses that use latex cores, usually dunlop is used all the way through or atleast the core).  Talalay process you will usually see made in synthetic blends, although sometimes 100% synthetic (like the stuff Sealy makes for themselves) or 100% naturally sourced Talalay, although more rare, latex international makes some like this but its not very common because it is not typically as pure of an end product as 100% natural dunlop rubber so you don't see too much of this being used in a lot of the most expensive beds around. 

Realistically most Dunlop latex is 100% natural and most talalay latex available is a blend, this is the main reason why you would typically be right in assuming dunlop will be denser and usually is.  Natural rubber is much heavier than styrene butadiene.  Of course don't take my last sentence to describe what dunlop or talalay IS, always make sure you know what the breakdown of materials is.  Chances are if you laid on a piece of dunlop latex that felt really dead it was either 100% synthetic or just an incredibly high ILD natural content. 

Anyway I am gonna tell you WHY Talalay is primarily used.  natural and synthetic latex have inherently different densities, when you mix the two of them together they cannot mix evenly, not to mention that vulcanizing agents will also have different densities.  Since most talalay latex here is made by latex international I will use them as an example.  Especially since the product is made in the US, but the rubber comes from North Africa.  When a rubber tree is damaged in the wild the milk of the tree would come to the surface area and form a giant rubber knot to fight off infection, this rubber will normally solidify within a matter of hours with exposure to air.  To prevent this from happening ammonia is added to the natural latex to prevent it from curing.  I personally am not privy to the exact details on how long the rubber sits around before being processed but since they send it by boat I think I am right to assume atleast a couple of weeks would go by if not longer.  Because the latex sits around for this long the appropriate amount of ammonia must be added, the more ammonia added the more vulcanization agents will need to be added to cure the end product.  So as time goes on you will always have a slightly less pure end product.  Once you have all these ingredients in a blend it is basically out of complete necessity that they must use the talalay process or there would be huge inconsistencies in the product.  On the flip side if one was using 100% synthetic or natural latex there really isn't much of a mixture at all in the first place and therefore no real need to even use the talalay process.  especially if the latex is processed close to the plantations as it will not be sitting around as long and very little extra chemicals will have to be added.  This is one of my biggest gripes with the industry constantly telling people Talalay is more consistent, obviously it is more consistent blend when you are using a blended latex, however it is actually the blending of latex in the first place from which almost all the inconsistencies are born from.

As far as what is bouncier, natural rubber is more elastic than synthetic rubber.  This is exactly why condoms and medical gloves still use natural latex because for safety reasons these things need to be able to stretch without breaking, synthetic rubber is far more brittle and actually more prone to cells being destroyed from compression and stretching due to a lack of elasticity.  This is also why density doesn't always mean a product is 'better' but the extra weight of natural latex is from proteins which make it more elastic, which is typically very desirable.  And would also mean the cores can conform more articulately with the shape of the human body.

I  could actually go into much greater detail but I am afraid I have a short story here no one will read anyway lol.  in closing though, you can compare Talalay to Dunlop in terms of ILD ratings quite fairly, however try to make sure you are comparing the same source material.  It wouldn't be fair to compare a synthetic blend talalay to an all natural dunlop, I would say this also works vice versa but as I mentioned no sane manufacturer would make a blended dunlop.