Mattress Forum

When a rubber tree is damaged in the wild the milk of the rubber tree (latex) comes out and will actually naturally harden within a relatively short period of time.  Ammonia is typically added in large volumes in the shipping containers so that this does not happen during transport of the material.  Even a small amount is usually added even if it is processed in SE Asia.  

When it comes to sulfur content, zinc oxide, or ammonia...it has nothing to do with the process used...it has to do with vulcanizing natural rubber in general.  If you want to see the purest rubber around you have to get access to Eco Instituts test results for varying manufacturers that submit to testing.  GreenSleep and Cocolatex for example even publish these results so you can know the specific amount of sulfur content and also a super long list of VOC's that they test for.  These are both Dunlop latex foams...there is now some certified Talalay latex but none of these companies have published their results.

Thanks again! Really appreciate you sharing your knowledge with us forumers.

Its not too fair for me to speculate too much.  Most certified dunlop producers do not publish their results either, they usually just list that they have some kind of certification for 3rd party testing.

Budgy thanks for all the helpful posts.

Some questions from me.

1  Which latex lasts longer and which one does not sag?

Synthetic talalay or Natural talalay?

2.  what is the softest dunlop latex? who is making it?

3. For me I am having low back pains.

Should I be choosing synthetic talalay or natural talalay

or dunlop latex?

Thank you budgy

Please do keep in mind that I can only answer these questions based on my own and my customers varied experiences.  

1.  Natural rubber is more elastic than SBR (styrene butadiene rubber).  In theory, natural rubber should last longer, other than perhaps in a land fill where it will biodegrade quickly and SBR will linger on and on.  The only latex mattresses we have ever had excessive sagging issues in were made with blended talalay (30~40% Natural, 60~70% synthetic), and to be fair all of these ones so far also had some polyfoam in the quilting layers as well.  Although there was a customer in recent history that had issues, I went to inspect the mattress.  Even though the blended talalay core was not sagging, it had softened noticeably in one area.  That particular spot the cover on the mattress was discoloured with perspiration stains, if someone is a heavy perspirer, they may want to consider having a thicker wool cover to protect the latex.  Whether the latex is natural or synthetically blended nothing will break down rubber faster than the salts in our perspiration.  

2. I really couldn't say because there are so many dunlop foam producers and I have only examined/worked with a limited # of producers.  I can say in my opinion there are some fairly soft all dunlop latex mattresses available, the 6+4 Natural rubber from Sleeptek is one.  They make the naturally organic line for thecleanbedroom.com, the Suerte organics from the denver organic mattress showroom, and I also have this product in our store in Canada.  GreenSleep Dolcezza Model in the softest configuration is usually soft enough for most people as well. Unless they want marshmallow soft.

3. Lower back pain is usually a sign that your natural posture is simply not being supported.  This can be caused by many things, it could even be the posture you keep when you are laying in bed.  Before you buy a new mattress you should always evaluate some simple things like sleeping position, perhaps your pillow is propping your upperbody up too much and causing your back to be out of alignment.  There are a couple of prevailing myths concerning mattresses.  One is that people should sleep on a firm bed...firm does seem to be good in terms of keep our posture well, although it may be lacking in comfort, it decreases bloodflow and increases sleep fragmentation.  Soft mattresses are no good either because they hammock and do not support the spine properly, in the long term in can directly lead to scoliosis.  A good mattress (regardless of materials used) is supposed to be elastic and flexible.  This way it can support your entire body without being harsh on pressure points.  Soft and firm are subjective terms, a 100 lb person laying on one mattress may find it to be 'firm' another person @ 200 lbs may find the mattress to feel 'soft'.  Elasticity is objective, measurable and scientific, natural rubber is more elastic than synthetic rubber.  So in theory the better performing material then would either be natural talalay or dunlop latex.  Perhaps a combination of the two depending on your comfort preference.  Whether you also find it worth the price premium is debateable I suppose. But in the interest of trying to be as factual as I can be, natural rubber is better performing than synthetic rubber, much in the same way that synthetic rubber will outperform brittle polyurethane foams, flexible boxsprings outperform solid boxsprings (if designed correctly), and individual coils will conform better to body shape than interactive coil types (again if designed correctly).  

I happened to be looking at a Stearns and Foster 97% latex mattress just for fun (I was really there to look at their Intellicoil pocket coils which are made from one wire twisted into a spring within a spring; very ingenious design). Anyway as I was trying out the latex mattress a representative from S&F was there and asked me if I had any questions! Boy, did I! I am sure he did not expect to encounter someone who was well-versed in latex specs and who in all honesty probably knows more about it than he did.

However, he made the claim that natural latex will NOT last as long as synthetic latex (i.e. retain it's positive properties). I said I had heard different and was skeptical. He insisted that S&F's synthetic latex would last longer than natural. I can almost believe this or at least believe it is possible, because I have also heard it said with great conviction that Talatech latex would last longer than natural latex. (Talatech is made by Latex International who also makes the best natural latex, or one of the best.)

I am not saying one way or the other, and I do not mean to pick a fight with my friend Budgy who probably has more knowledge of latex than anyone here. But I do wonder if any really conclusive tests have been done that would prove one way or the other whether synthetic latex will provide support longer than natural latex. I doubt anyone has actually proven it, or vice versa.

One thing I did want to add is that when you go around shopping for latex, you have to be very careful because a lot of salesmen in stores will pretend to know and not really know what they are talking about. And remember always that "Talalay" is a process not a type of rubber. So synthetic latex can also be Talalay or Dunlop processed. "Talalay" does not mean "natural", it can be synthetic or natural. Stearns and Foster and Simmons both claim to use Talalay latex in their mattresses but it is synthetic. Again, whether that is bad or good is debatable.

I will also note that natural latex will turn to dust if left in the sun or extreme heat, as will synthetic. I have latex which is getting very dry. Frankly I don't know if it's Talatech or natural but it is getting very dry and brittle because I have at times left it laying where sunlight reaches it and dry hot air. Budgy, have you noted that natural latex will deteriorate from being in heat and sun? Will it not then also deteriorate (but slower) inside a mattress?

Based on the rubber samples we have had in our showroom I would say that natural rubber is more resistant to UV radiation than synthetic as well, but this is less than scientific because its not like this is controlled testing...just more an empirical observation.  But its not good for either one, in a mattress this typically shouldn't be an issue.  I just have a really hard time believing that blended rubber or synthetic rubber would be more durable given that it crumbles so easily compared to natural dunlop.  Perfection Mattress has a good group of informational videos on youtube, he had a customer that bought a 5" Natural Dunlop mattress from Sears made by GoodYear.  This particular mattress had lasted basically 50 years before they replaced it...the only thing wrong with it was the completely destroyed cover.  This is most likely an exception and certainly not the rule on how long any natural latex bed should last.  But basically what I am getting at is that natural rubber beds have been made for a long time, and we know because of how many of them have sold and that most last like 20+ years that they are an incredibly durable mattress type. We have also sold about 500 latex mattresses in the last few years, about half of them are blended talalay latex (lots of childrens mattresses though), and the other half are 100% natural, some with talalay, but most with all dunlop construction. Out of all those mattresses, we have had 3 issues with blended latex mattresses...believe me this is actually exceptionally good compared to all the S brand stuff we used to sell where warranty issues (just the ones that qualified...probably some that we dont know about as well) was in the range of 4~8% failure rate inside of 4 years.  More than half of those failures coming within 18 months of date of purchase.  To date we have no documented issues with 100% natural rubber breaking down prematurely, Talalay or Dunlop.  I am sure inevitably this data is going to change, but so far its in the lead for us based on customer complaints and documented warranty issues.  Note, this does not mean they are 100% successful in terms of comfort...just no defective products that we know of...yet.

When synthetic foam producers tell me their products will last longer...are they basing it on this kind of data?  Have they even been selling the product long enough to know how long it will last?  Phoenix had some very good information regarding why Natural Talalay latex is not currently made in the super low ILD's because of shear type force loads that could cause issues and how if natural rubber is made too low of a density it's elasticity will work against itself because of shear force (literally being stretched apart because the rubber is so flexible).  Anything above high teens in the ILD's the elasticity of natural rubber just helps it bounce back without losing firmness and the elasticity generally helps the durability.

Also knowing that UV radiation and the chemicals in our sweat are what causes rubber to break down faster than physical forces like those replicated in manufacturer testing (giant rollers beating on the foam), these kinds of claims also seem highly irrelevant to me.  What is relevant to me is real world data and experience. 

If synthetic latex was superior then why on earth would the same company blend any natural rubber into the mix at all when the cost of doing so is significantly higher?  it would be much cheaper to make the product 100% synthetically. 

Why does this company promote the blended or synthetic product to be better than the all natural when they charge basically the same for both? because they want you to buy the cheaper more profitable product. 

The last point being the main reason I still say that blended rubber is an awesome material to use in a mattress...but if the price difference is really small I would pay the premium to sleep on natural rubber. In our store the blended latex products are signifcantly less expensive than the all natural ones....so we carry both. Above and beyond all of this, is the whole chemical aspect, the resistance that natural rubber has to allergens like dust mites, moulds, bacteria....SBR is lacking these properties and at the end of the day it is a petroleum product.

Budgy, I called sleepez 2 times and the same guy told me that blended talalay latex lasts longer then natural talalay latex. And laso that it contours better to your body then natural talalay latex.

Do you think SleepEz does not know what they are talking about?

I think that a lot of retailers have been sold the story by Latex International to believe that their talatech latex foam is somehow special.  I am not going to say its inferior by any means, just that at the end of the day these are businesses, and businesses are driven by profit more than integrity.  I have yet to see any proper scientific comparison done between blended talalay and natural talalay, 'pressure map' tests done without numbers being listed, and claims by industry representatives is all we have.  Wikipedia has more relevant information regarding the differences between SBR and NR. 

Here is one of the few objective and scientific comparions charts on different rubber compounds. 

http://www.elderrubber.com/material.htm

In all the important ways, resilience, tear resistance in particular, NR vastly outperforms SBR. 

http://www.elderrubber.com/material1.html

Here is another chart showing that NR has higher resistance to UV radiation...also note the tensile strength is highest of all rubber compounds.