Durability of latex with respect to harmful reactions and firmness

Is 100% natural latex immune to some reactions that degrade blended?

My understanding was that, at least with Talalay, blended latex is supposed to be more durable than 100% natural. But I chatted with someone through habitatfurnishings.com about their latex toppers and they claimed that:

Edit forgot to include this quote from the chat:

And they have an FAQ on their site that says:

Are their claims accurate?

How does durability of blended Talalay / Dunlop compare with 100% natural? Is 100% natural immune to some threats to blended, such as UV – or vice versa, blended immune to threats to natural?

How important is a protective cover for 100% natural and blended respectively? Would a fitted sheet style mattress protector provide adequate protection for a latex topper?

When shopping for blended latex, should I be concerned with what the proportion of natural to synthetic is?

This site says:

What ILDs is this talking about? Is it just the N1 firmness? If 100% natural latex is advertised with an ILD rating as opposed to N#, what ILD would this be applicable to?

Hi Catatonic,

You are getting some incorrect and/or misleading information here.

Not “immune” no but there are some differences between the properties of synthetic and natural latex in terms of how they age. Post #6 here has more information about the different types and blends of latex and post #2 here has more information about some of the differences between natural and synthetic rubber.

If they are referring to blended vs 100% natural Talalay then the manufacturer of the latex they use would disagree with them (see this page on the Pure Latex Bliss site which is owned by Latex International).

Antioxidants or antidegradants are added to latex formulas to reduce the effect of ozone triggered by UV light. You can see from the list here that ozone is one of the factors that can have a “severe effect” on natural rubber but it’s less for natural rubber than synthetic rubber because of the difference in their chemistry and polymer backbone. If you put a natural rubber layer out in direct sunlight for a while it could certainly harm the latex.

This again is misleading and puts the focus only on natural vs synthetic (which is more “marketing” information) instead of the specific type and blend of latex. It’s always a matter of specifics and degree and not just whether latex is natural or synthetic. Both types will degrade over time although all latex is more durable than other types of foam materials.

No

I believe it’s important over longer periods of time for the latex to have the longest possible lifespan. A fitted type mattress protector would be OK over the short term but I believe it would reduce the lifespan over the longer term.

The previous link probably answered this but in the case of Talalay you won’t have a choice (all blended Talalay is about 30% natural and 70% synthetic) but in the case of Dunlop it can make a difference both in the cost and durability … again depending on the specifics.

It would be a curve not a sudden change and would probably depend on many factors such as the body weight of the person and the position of the layer in the mattress but in very general terms I would say based on many conversations that they would probably even out somewhere in the range of mid 20’s ILD or higher.

You can see the range of ILD’s for each firmness level of Latex International’s 100% natural Talalay here.

Phoenix

Hi Phoenix,

Thanks for your reply.

Thanks for the links, I read those posts.

Yeah, that’s interesting. That is what they were referring to. Here is an excerpt from the chat:

And the synthetic polymer tested in that study was SBR, or the results can be applied to SBR I take it.

So in your viewpoint their statement that “Natural latex is not photo sensitive so UV light does not harm it or cause it to break down.” must be quite an exaggeration.

Ok. This is just one of the many things about beds and latex where it’s hard to get consistent, straightforward answers. I was looking at some toppers on mattresses.net and on one page that includes blended Talalay, all natural Talalay, and all natural Dunlop it says:

While on another page for all natural Talalay it says:

I asked them about it by email and this is what they replied with:

Ok, thanks. I’m only looking at Talalay at the moment, so that’s good to know.

What exactly do you mean by even out? Are you talking about where durability of 100% natural and blended would be equal?

I think I want something in the neighborhood of 19 ILD Talalay, 2-3", for a top comfort layer. So 19 ILD is right around the border between N1 and N2 (at least when talking about Latex International foam) right? For average / below average weight people, do you think N1 is too soft to recommend? What about N2?

Another issue is that 100% natural Talalay in N2 could end up feeling like 25 ILD blended Talalay, right? So if I want something more like 19 ILD, am I better off getting blended just because of that?

Thanks for your help

Hi Catatonic,

Here’s a few more links from different manufacturers that show some of the properties of different types of rubber that also indicates that without antidegradants in the forumla both SBR and NR are both susceptible to UV (sunlight), and ozone.

http://www.elbex-us.com/pdfs/General%20Properties%20of%20Elastomers.pdf
http://www.viprubber.com/page/technical_advancedmaterials (click on NR and SBR in the side menu)
http://www.rlhudson.com/material_profiles/index.htm (click on natural rubber and styrene butadiene in the side menu)

Yes … this would be my “best guess” based on my research and conversations and subject to the many other factors that can affect durability.

ILD is only one part of why any materials feels soft or firm and by itself can be as misleading as it can be helpful (see post #2 here). Every layer of a mattress will interact with every other layer in different ways and outside of personal testing or experience, the best way to decide on how suitable a particular mattress design may be is with a more detailed phone conversation with a knowledgeable and experienced manufacturer or retailer who will know more about how their mattresses match different body types, sleeping positions, and preferences “on average” than anyone else. There are just too many variables to be able to predict how anyone will “feel” on a mattress based only on ILD because there are too many other factors and variables involved (see mattress firmness/comfort levels in post #2 here). ILD is also not exact with any material (even the ones that list a specific ILD) and will fall in a range (see post #6 here).

Because it’s unknown how any specific cover or covering method will affect the latex inside it and allow light, oxygen, and ozone or other things that can affect the latex to go through and potentially speed up the softening or breakdown of the latex over time … I personally tend to take a more conservative approach with these types of issues and err on the side of caution and would put a cover on bare latex layers for long term use.

Phoenix

Hi Phoenix,

Thanks for these.

Ok…I’m guessing that means N2 all natural Talalay would have decent durability then.

The first link in this part didn’t work for me (“You do not have permissions to access this page.”). I’m not sure, but I think you may have interpreted my question to mean “do you think N1 / N2 is too soft to recommend for comfort” – what I meant is do you think N1 / N2 (respectively) are too soft to recommend for durability reasons. I don’t think I have a choice but to take an educated guess about what to buy – the opportunities to try materials like latex locally are just too limited and impractical. And at this point I’m planning to get a 2-3" Talalay topper of approximately 19 ILD blended or N2 all natural (these are the only measures I know of to identify the firmness I want). It’s a shame that the ILD ratings are not a very objective measure, but I don’t have much else to go on than the combination of latex process, composition, ILD, and manufacturer. As you noted in one of the posts you linked to, word descriptions of firmness are very subjective, so I’m not sure that talking to someone on the phone would yield more reliable information. And at this point I’m just shopping for a topper, so I’m not sure how well someone on the phone would be able to guide me since they don’t know how it’s going to feel on my mattress, even if they’re very knowledgeable about their product.

So you’re saying it’s unknown how well any particular covering will actually protect the latex, but you believe that any covering is better than no covering? And I take it you mean a cover that encases the latex as opposed to the fitted sheet style of mattress protector I mentioned?

Thanks

Hi Catatonic,

I linked back to a reply window on this thread instead of the post I meant to. Thanks for letting me know and I’ve fixed it in the original post and in your quote.

N2 Talalay is in a 20 - 25 ILD range so it would be more in the low 20’s normally. While it’s certainly a durable material compared to other foams and some people may prefer it for personal reasons … if I had to guess at how it compared to LI blended in the 24 ILD range I would say that the blended would be more durable (although this is based on preponderance of the evidence and best judgement). N3 would probably be where they were more comparable.

I would be fine with almost any latex in terms of durability (subject to the other factors that can affect durability) so it wouldn’t be a durability issue for someone that preferred all natural over blended Talalay and their “other reasons” for choosing it were more important than differences in durability. At your weight I wouldn’t make its durability an issue with either one and how it feels and performs in the mattress you are looking at would be more important but if the lower cost of blended Talalay was important to you and you were OK with the idea of using a blend of synthetic/natural for personal reasons or for some reason durability was the most important part of your personal value equation even if you didn’t like it as much in terms of PPP then I would choose the blended in a roughly equivalent ILD range, which would be 24 ILD, or in 19 ILD if I wanted something a little bit softer than N2.

In the absence of personal reference points, I would tend to use the suggestions in the topper guidelines which are based on how your mattress feels and how much additional pressure relief you are looking for as best you will be able to quantify it. If you are uncertain then the return or exchange policies may be a more important part of your personal value equation than any specs because it will give you a much more meaningful reference point for a replacement based on your actual experience with the topper on your mattress instead of relying on “theory” which can become an exercise in frustration or in some cases “paralysis by analysis”.

There are no specifications available about airflow or light, UV, and ozone penetration of different covers or covering methods that will give you any accurate means to compare them and there are also no specs available about the actual resistance of every latex formulation or the anti degradants they use in their formula. A cover can also help protect the topper from other types of damage so using a cover that fully encloses a topper is what I would personally do for the long term if I was buying a topper. This is once again be based on all the research I have done and the conversations I have had with many people in the industry and is based on “preponderance of the evidence”, “best judgement” and perhaps a little bit of extra caution that gives you higher odds of better protecting a high quality material from degrading more quickly than it otherwise would.

Phoenix

Hi Phoenix,

new topic about topper coversThanks for your reply. I’ll respond to your whole post later, but I wanted to let you know that I made a ]post about topper covers[/URL] that relates to what we were discussing here. It made more sense to create a new thread for it than to post it as a reply here.