Mattress Forum

When you have a mattress that is made of closed cell foam such as what is mostly used today you have a structure on top of a spring system that is designed to support your body....think in some pillowtop mattresses now there can be copious amounts of foam (over 5 inches), enough in some cases that the spring system itself is essentially irrelevant.  The issue with closed cell polyurethane foam is that you essentially have trapped air inside each cell...when this is compressed you are forcing air through a closed cell wall into adjacent cells, causing degradation to the cell walls and reducing support.  Eventually leading to a body indendation and a noticeable loss in support as the cell walls are collapsing far more easily.  This is something that most people will feel happen even before a significant body indentation is formed.  Think of Tempur-Pedic as a prime example.  It is a very dense material that is quite resistant to permanent body indentations compared to normal polyurethane foam....yet the mattresses always become softer with use due to the same phenomena.  The inherent issue of polyurethane foam in essence then is not simply body indentations, it is the material itself softening up unevenly inside the mattresses making it virtually impossible to get good spinal alignment after a certain point of time.  The denser the foam the longer this generally takes to happen.

When natural fillings are used body indentations still occur.  However the way in which the material breaks down is very different from foam.  Wool for instance is a good example of a durable elastic fibre. The material compresses easily and will take on a permanent body indentation as well when stitched right into place.  However it does not soften like polyurethane foam does. There is no breakage in the material itself, atleast not for quite some time.  The same is generally true of most natural fillings...they actually become firmer when compressed.  This is why old school mattresses used to get firmer with initial use despite metal fatigue, and modern ones get softer.  Foam is being used instead of natural fillings.  Now at a certain point if you get enough permanent indentation in a mattress with no foam it might still become undesirable as the shape of the mattress is potentially preventing you from also acheiving that ideal alignment or it has simply gotten too firm.  There are different stats for different types of fibre, however thick cheviot types of wool can bend over itself 10,000+ times before breaking, each fibre is essentially a little spring. Cotton batting depends on what staple of cotton is used....horsehair is supposed to be incredibly elastic (they even used skeins of horsehair in ballistas to launch spears hundreds of yards). 

Before I got rid of the S brands this year they were asking me what kinds of mattresses we are doing well with at the same price points they were going for, I was telling them about Natura's new line called GreenSpring...contains cotton batting and sheeps wool, everyone said "cotton batting?! good luck with that, and the body indentations".  In reality they are probably right about the indentations although I doubt any more severe than what we have dealt with in the past relying on polyurethane foam and polyester to do the work.  If they are all going to compress, why sleep on plastic?  So the same companies that 30 or 40 years ago said those indentations were a sign of the mattress working properly have since turned their backs on that era and now make other beds that also compress (much more so) and are still saying that "high quality" materials are meant to conform to the shape of your body and so long as its not excessive its a desirable thing.

Rubber on the other hand is one upholstery material that not only keeps its firmness well like other natural fillings, but also does not compress very easily.  They usually still take some body set because they are either upholstered with polyfoam containing FR's or wool.  If it was perfectly legal to just sell a mattress with no quilting layer and just a solid slab of rubber than we could have mattresses that might visually look great although wool tends to keep everything nice and dry which means cleaner in the long run and probably healthier overall to sleep on. 

Or we could sleep on mattresses made out of coconut coir and that would also probably last virtually forever,  just not going to be terribly comfortable.  Generally though, body indentations are not a good thing when in excess, its the number one reason I think people replace their mattresses.  At the same time any mattress that will yield and conform well to body shape will likely take some permanent indentation.  One thing I do agree with wholeheartedly is that these complex layering schemes really do go awry and most mattresses are ridiculously over complicated given the simple task they are supposed to accomplish.  I think so long as someone has acheived their desired comfort preference when it comes to upholstery less is more.

This is also the reason guarantees are worthless. Even when a foam has lost it's compression resistance and has become really soft, it still "comes back" most of the way. It's just become really weak. To be able to take advantage of a guarantee, the depression (1.5" - 2") has to remain without any weight on the mattress and of course the manufacturers know that that is unlikely to happen. Long past the point where the mattress becomes unuseable because of loss of support and foam degradation, it is still "fine" according to the guarantee.

"So the same companies that 30 or 40 years ago said those indentations were a sign of the mattress working properly have since turned their backs on that era"

This was what I was trying to get to in my post. Was it really a sign of the mattress working properly or were they just saying it even then. Were body indentations to a certain degree (using compressable materials that don't degrade and get harder over time) functional? Was the idea of the time to make sure a body impression would happen "in a certain way" (not too much and not too little)? Was the choice of material used in the stuffing all about "customizing" the body impression to make it fit the customer?

Nowadays with the different foams playing a more active role in support (to the point where as you said in some cases springs are almost irrelevant) when the foam wears (softens and degrades) you lose a major part of what makes a good bed. With the more traditional stuffings, as the bed would "wear" or break in, you could actually improve your sleeping surface to some degree.

Was most of the mattress "design" of the time about choosing stuffing material (to manage body impression) and springs (to customize the supportive or "active" part of the mattress) and how much of the effort was put into each. Did people argue even then about the benefits of different materials and the quality or strength of different springs or was there more "consensus" on what made a good bed and the choices were more about price?

Phoenix

Just to clarify: by "back then" I am meaning from the beginnning of the more widespread popularity of innerspring mattresses in the 1930's up until the widespread popularity of polyfoam in so called "quality" mattresses which probably runs roughly parallel with the popularity of the memory foam mattress from the 1990's onwards.

My new BR which is a much cheaper crappier model (of course, since that's how they're made now) is about 1 month old and is getting body impressions and I"m happy with that. I personally prefer body impressions to foams because I just get too darn hot on foam. My biggest concern with my new mattress is that it's going to do what we expect it will do--develop deep undesirable "body impressions" that make the mattress unuseable, within a short timeframe.  I put body impressions in quotes there because I think that when they get too deep, they are no longer body impressions per se (which are a good thing) but defects or breaking down of the mattress.

If I wasn't feeling so desperate to get a new mattress, and if I had not already spent $1600 just over a year before, I would have gone with one of the "old fashioned" mattresses which are still available if one looks hard enough.  And next time, I just might.

I really hope this one lasts, but I fear it won't.

I don't really think so.  I take Hastens as a good example...they make their mattresses out of horsehair wool and cotton on top of springs.  They claim that about 50% of their customers prefer the mattress feel after some initial indentation and the other 50% periodically do the massage technique to their mattress toppers to reloft the fibres.  I think that those who have legitimate back problems will likely find the flatter the mattress surface the better it seems to be...while those that simply like to feel nested would like a little bit of settling in these materials.  Again though, with limits. 

The whole conforming to body shape thing should be inherent in a well designed mattress, natural fillings have less 'structure' than any variety of foam therefore can conform far more precisely to body shape even before they have compressed permanently.  A flat new mattress can do this as well as one that has broken in so long as they are designed well.

Just noticed the comments about body impressions near the bottom of the page.

There is so much interesting stuff all over the place about mattress construction and philosophy. I had no idea I would get this involved (laughing)

That is one reason zoning makes some sense (with either different firmness of springs or foam).

The third way would be form the mattress conform more to the body shape.  Either by not having a flat surface to start with or by the underlying materials mold to the body.

Obviously, if the impression is due to foam losing it structural support (the most common case), then it would be a bad thing.

Body impressions seem to be unavoidable yet it seems clear that certain materials will get them less than others. Natural latex is one that gets them less than others.

Then there's memory foam which is built on the concept that body impression is good. I think the idea of memory foam is good in theory but they have not perfected it. The fact is it breaks down too fast for many people who have sensitive backs. I believe the people who like it are mostly people who "can sleep on anything" (even though the advertise it as being good for bad backs). I'd be curious from some of you who sell mattresses (Budgy?) if you fid that to be true: that people with bad backs are more likely to NOT like their Tempurpedic. That would be my guess, based on my own experience. It started out great and after a week or two it was killing my back due to not having enough support.

I think it is clear that cotton batting and wool and silk and such natural materials make a better mattress, no? It's just that most people can't afford them.

I think the bottom line on the mattress industry today is that not only do they use cheap material like PU foam but they use the CHEAPEST of the cheapest, crappiest of the cheapest PU foam in order to make a mattress that feels fine in the store but will end up breaking down in only a few months - after the exchange option is passed.

I also think that probably a good 50% or perhaps much higher percentage of people "can sleep on anything" and that's how they get away with making and selling so many cheap crappy mattresses.

Those of us who have sleep "issues" such as bad backs or bad shoulders are the ones who have a helluva time finding a good quality mattress that works for us, and for us these cheap mattresses with PU foam are simply not going to work. I wish I was a millionaire  - for many reasons! ;-D But for one thing, so I could go out and try some really high end mattresses made with materials like cotton batting and wool and silk and see if one of them might actually give me a satisfying night's sleep.

Meanwhile I believe that DIY mattresses are the only option for those who aren't rich.

The big S's used poly foam because it solved two problems - it was about the same price as garneted cotton (at that time) and it met GOVERNMENT regulations to make mattresses resist combustion from a smoldering cigarette.  In fact most of the major companies kept using cotton with poly on top of the cotton because we thought cotton made a good mattress.  Cotton has some drawbacks - ever try to dry a cotton mattress after it got wet?  If a cotton mattress did have a cigarette drop on it it was not uncommon to smolder for hours before bursting into flames!

Yes there is cheap poly out there and there are cheap manufacturers who will use it - but it is cheap... why are you even looking at that kind of product?  The better manufacturers use very good high quality poly.  TDI a componet used in the making of poly is in very short supply so the poly makers would rather not use their limited supplies of TDI on junk poly.  Poly is not all that cheap.  But it does make sure that the mattress you try on the sales floor feels like the one you get home.  Thats a good thing.

Major mattress makers now have to meet new government regulations (1633) and having been on the manufacturing side I can tell you, you may not have any idea just how difficult it is to make a mattress resist an open flame of 1180 degrees for 60 minutes at five different ignition points on a mattress without bursting into flames - and do this on a national basis - meaning perhaps as many as 30 factories can get the same certified raw materials on a consistent day to day basis to meet their volume needs.  Remember there are lots of ways to meet federal 1633 regs, but only a few are applicable on a national level for 25 - 30 factories needing a reliable supply ot make mattresses five or six days a week.

As far as mattress makers making the cheapest stuff designed to last just a day or two past exchange limits or warranty limits then again I ask just what kind of product do you buy?  There is cheap product for sale and there is High vale product but at a higher price, and better performance.  However, no matterss maker can make product that will solve all sleeping problems, back problems, alergy problems, or every other problem that people want a mattress to fix.  Remember factory owners are just that factory owners - they have invested their personal money because they think they can do this as well as others or better than others - and because they are taking a risk with their own money they want a return on that investment - that seems fair to me!

If you are upset because they can't solve your sleep related problem - have you asked your doctor how to solve your problem?  And if they (Doctors) just want to throw drugs at you, or invite you back evey week for two years for another adjustment, or another round of having pins stuck in you... charging you each time for their services, and you go...    Yet we get upset at mattress makers for making money...

Most every mattress factory owner takes great pride in the product they make.  Not every maker wants to be that ultra high end mattress maker but they see a need they can fill and they make the best product they can make for a price that will sell - time after time to meet a need.  But they have pride in what they do. Most are not out to just make a buck and run! 

Now if the market place is demanding lower and lower priced product and there are only three ways to meet that demand - cheaper raw materials, lower profit margin, or new types of raw materials or technoligies - then you through in the government says certin standards have to be met, then a class five hurricane wipes out half of the worlds supply of TDI,  you have to believe mattress makers are doing a very very good job!!!.

Gunman

There are quite a few who are claiming that their polyfoam is superior to Latex http://www2.basf.us/urethanechemicals/Specialty_Systems/fb_pluralux.html

Energia from Foamex is making similar claims (which they also did with resilitex which has been discontinued) as are many others.

Part of the problem I believe is that the newer and better polyfoams are not "real world" tested in terms of how long they really do last and keep their qualities. Resilitex was supposed to be amazing but then apparently the complaints started rolling in. There could be other reasons that I don't know about why they discontinued making it.

What is clear to me from the research I've done is that for now, I don't trust them as much as latex ... at least in the upper layers.

And the fire regulations in my opinion are a joke. They enact laws to "keep people safe" and protect them from themselves yet at the same time who knows how many health problems have been caused with the toxicity of some of the solutions .... not to mention the money they have cost consumers and the (mis)direction it led the mattress industry.

Phoenix

Jim: Good question about what our customers experience.  I can actually say whole heartedly that on Tempur beds in general people are much happier than on a typical mattress....but....yeah we have had people with legitimate back problems or even pressure relief issues find a good dunlop latex mattress with a healthy layer of wool to be better.  100% of our customers that ever brought back a Tempur on a comfort exchange went for a latex mattress of some variety or another and all have since been happy, two thirds of that crowd now own a Green Sleep mattress.  All told though, way less problems with that product than say a typical pillowtop mattresses which we have seen break down excessively within as little as 3 months.