Sofa shopping

17 04 2015

We did a series of posts on how to evaluate a quality sofa about two years ago, and judging from the questions we get from people, we thought it might be time to re-post these!  The 3-part series is divided into evaluating a sofa frame, cushioning materials and fabric (of course!).  Herewith, the first post:

So you’re shopping for a sofa, and you see this one in a store.

camille 1

In a different store, you see the one below.

blue sofa

One sofa (the one on top) costs $3000;  the other costs $1500.  Why the wide disparity in price?

Shopping for a sofa is fraught with anxiety – we don’t do it often (for most people it’s every 7 – 10 years) so we don’t know how to shop for it.  Knowing what to look for, and how to evaluate a sofa, might take some of the anxiety away.  And knowing a bit about the components and how they’re put together will explain some of the difference in price.  It’s important to keep that in mind while you’re being seduced by the alluring upholstery, svelte arms and come-hither cushions.  But if your darling’s joints are weak, springs loose and cushions flat, you’ll quickly lose that lovin’ feeling.  Not to mention the additional chemical guests you’ll be inviting into your home with the sofa.

Start by asking yourself questions such as who will use the sofa  – will the kids dump themselves and their bags on it right after school or is it in a room that’s just used for entertaining?  How long do you want it to last?  Do you want to sink into the cushions or sit up straight?  Nap on the sofa?

One of the first things you should do – really before doing anything else –  is look at the sticker price and concentrate on the amortized cost  (cost per day) of buying each one.  There is a reason for the price disparity – they have to cut corners someplace, so lower quality materials are used

And construction is …  well let’s just say it’s not built to last.  “Quality” translates into “useful life”.  For simplicity, let’s assume the top sofa will last 20 years while the bottom sofa will last just 5.  That would mean the top sofa costs $0.41/day while the bottom sofa costs $0.82/day = exactly double.  The cost of owning the top sofa is half as much as the cost of owning the bottom sofa.

Dr. Thomas J. Stanley, in his book The Millionaire Mind, observed: “By definition, millionaires tend to be accumulators, a trait they inherited from their parents who were collectors.  Their parents and grandparents held on to things that had value. So the majority of millionaires have a family legacy of collecting, saving, and preserving.  Waste not, want not is a theme acted out by first-generation millionaires today”.[1]

With regard to how this trait applies to buying furniture: They deliberately purchase furniture they can pass on to the younger generation.  This, in essence, is their definition of quality furniture.  It will outlive a person’s normal adult life span, will never lose its appeal, and will probably appreciate in value.[2] A good quality sofa is an investment, like any other quality purchase that you expect to last.

For the next few weeks I’ll break a sofa down into component parts and talk about each one separately, starting this week with the frame and suspension system:

FRAME:

A very low cost sofa is probably made of engineered wood – such as plywood, particleboard, Medium Density Fiberboard (MDF) or glulam  –  all of which can legally be referred to as “solid wood products”.   Engineered wood (or composite, man-made or manufactured wood) are made by binding the strands, particles, fibers or veneers of wood with adhesives – most often that means urea formaldehyde (a known carcinogen) and finished with polyurethane or aluminum oxide.  In laymans terms, MDF (for example) is sawdust held together with glue.  MDF has a life span of 1/10th to 1/4th that of solid wood, properly constructed – and costs about 1/10th to 1/4th that of solid wood.  Cutting, sanding, or releasing particles of MDF into the air might be a high risk and should be avoided.  If the MDF isn’t properly sealed, it can leak formaldehyde for years, pumping it into your home or office.

Often manufacturers use wood veneers over MDF cores, and consumers have no idea that they’re not buying real wood.  Veneers are also used on solid wood (usually a less expensive wood) –that has a similar property as the veneer, allowing them to swell and contract together with changes in humidity.  They also respond similarly to stain and finish products. The bond between manufactured wood (MDF) and the veneer is not as strong or stable as that of the solid wood because MDF tends to respond more dramatically to changes in humidity and temperature, and is more rigid than solid wood, making the bond less durable.

Recognizing solid wood veneer furniture is fairly simple. Look to the bottom and back edges of tabletops, drawers and shelves. Solid wood always has grain, whereas MDF and particleboard do not. These unexposed edges will not typically be veneered.

Another thing which is often cited as a way to evaluate quality is to pick up the sofa – if it’s really heavy, it’s probably made of solid wood – or so the saying goes.  However MDF is also very heavy – so weight alone cannot really be used as a test.

At the next step up, soft woods (like pine) may be used.  The highest quality furniture uses kiln dried hard wood, like ash, maple or poplar, which offer greater strength and stability.  But not all wood is created equal: we think that it’s important to choose a wood that did not come from an endangered forest (such as a tropical forest), and preferably one that is sustainably managed, because forests, according to the National Resources Defense Council, are critical to maintaining life on Earth.  And that’s something we should pay attention to!   (See our post about wood used in furniture at https://oecotextiles.wordpress.com/2012/08/23/how-to-buy-a-quality-sofa-part-2-wood/ )  Wood certified by the Forest Stewardship Council (FSC) ensures that the wood used in your sofa was from a managed forest. SFI, an alternative certification created by the American Forest & Paper Association, allows such things as clearcuts, use of toxic chemicals, and conversion of old-growth forests to tree plantations. So the certifying body matters!

How the wood is connected is important too.  Lower cost sofas are often stapled together, or you’ll get plastic legs screwed into the frame instead of wooden legs that are part of the posts or bolted into the frame.   Give it a year or two and the arms get loose or the frame wobbles.  Higher cost sofas are held together with glue and dowels or tongue-and-groove joints, making the joints even stronger than the wood itself.  Corner blocks (in each corner of the frame, near the legs, an extra piece of wood joins the two side rails) are important.

Finally, the wood is often stained or varnished – both of which emit harmful VOC’s of various kinds, depending on the stains or varnishes used.  A safe alternative is to ensure that the stains/varnishes used don’t emit harmful VOC’s such as formaldehyde, and are formulated without aromatic solvents, heavy metals in the pigments, toluene solvents or other harmful chemicals.

SUSPENSION SYSTEM:

The suspension system determines the bounce in the cushions, and how they support your weight when you sit on them.   The differing degrees of pressure your body puts on the cushions causes the coils to respond, giving what is known as “ride”.  Generally, the higher the number of coils, the better the ride.  The gold standard has always been the labor-intensive, 8-way hand-tied spring system. It’s expensive to do it right, and few companies do. When done correctly each spring is set into the deck webbing and attached, with various spring rates depending on what portion of the seat deck its located. They are then tied together (8 strings per piece) and knotted at each juncture (not looped! – only knotting keeps the spring deck together if a string breaks). Much has been said about how eight-way hand-tied spring-up systems are superior to any other kind. “It’s a sacred cow in the industry,” says Professor C. Thomas Culbreth, director of the furniture manufacturing and management center at North Carolina State University [3].

But not all eight-way hand-tied spring-ups are built the same way, and the sinuous spring – or S –  system,  will last just as long, and for most people the comfort level is the same.  Sinuous springs are “S” shaped and run from the front of the seat to the back. These springs are supported by additional wires that cross from side to side.  The S springs lack the localized response of a coil system but gives a firm ride that some people prefer, and it has less potential for sagging over time.   It also makes for a strong seat, and it might be the preferred option in a sleeker style as it requires less space.

Next week we’ll tackle cushions, because that’s, as they say, a whole ‘nother ballgame.

[1] Stanley, Thomas J., The Millionaire Mind, Andrews McMeel Publishing, 2001, p.294

[2] Ibid.

[3] http://money.cnn.com/magazines/moneymag/moneymag_archive/2003/03/01/337933/

 

 

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Bisphenol A in textile processing?

16 12 2011

If you’ve bought baby bottles or water bottles recently, I’m sure you’ve seen a prominent “BPA Free” sign on the container.

BPA stands for Bisphenol A, a chemical often used to make clear, polycarbonate plastics (like water and baby bottles and also eyeglass lenses, medical devices, CDs and DVDs, cell phones and computers).  And though it has been formally declared a hazard to human health in Canada and banned in baby bottles in both Canada as well as the EU,  U.S. watchdog agencies have wildly differing views of BPA:  The National Toxicology Program (NTP) reported “some concern” that BPA harms the brain and reproductive system, especially in babies and fetuses.  The Food and Drug Administration declared that “at current levels of exposure” BPA is safe.

But consider this:  Of  the more than 100 independently funded experiments on BPA, about 90% have found evidence of adverse health effects at levels similar to human exposure. On the other hand, every single industry-funded study ever conducted — 14 in all — has found no such effects.  David Case made the argument in the February 1, 2009 issue of Fast Company that this is a story about protecting a multibillion-dollar market from deregulation.  But that’s beside the point  which is:    nobody disputes the fact that people are constantly exposed to BPAs and babies are most at risk.  It’s also undisputed that BPA mimics the female sex hormone estrogen, and that some synthetic estrogens can cause infertility and cancer.  If you’d like to read more about this click here.

Bisphenol A is now deeply imbedded in the products of modern consumer society.  This is important because it’s used in so many modern products (making it pretty much ubiquitous), and because it is extremely potent in disrupting fetal development. BPA contamination is also widespread in the environment. For example, BPA can be measured in rivers and estuaries at concentrations that range from under 5 to over 1900 nanograms/liter.(1)

What this all means is that most of  us live our lives in close proximity to bisphenol A.

Because it’s used to make plastic hard, I never thought it would have a place in the textile industry.  So it was with some concern that I came across articles which explain the use of bisphenol A in the manufacturing of synthetic fibers.

Producing synthetic fibers and yarns is almost impossible without applying a processing aid to the fibers during the extrusion and spinning processes.   The fibers and yarns are frequently in contact with hot surfaces, or they pass through hot ovens.  In order to withstand these extreme conditions, the yarns and fibers have processing aids or finishes applied.    This applied processing aid or ‘finish’, in addition to helping the yarns withstand extreme temperatures, also  reduces static electricity, fiber-fiber and metal-fiber friction, provides integrity to the filaments,  and altogether eases the manufacturing processes.

But because modern manufacturing equipment runs at higher speeds and subsequently at higher temperatures, the finish degrades in the high temperatures – yielding lower quality fibers –  and generates unwanted decomposition products.  These byproducts can be in the form of:

  1. Toxic and nontoxic gases which have environmental and safety issues;
  2. Liquids, which leave a sticky residue on the yarns,
  3. Or they may form a solid varnish on hot surfaces that is very difficult to remove; the presence of the varnish interferes with continuous, efficient production leading to economic losses due to equipment shutdown and product failure.

To overcome the problems caused by the degradation of finishes, several additives are introduced to prevent or delay the reactions of oxidation and degradation.  Several classes of antioxidants are typically used as these additives in these finishes.

In a study sponsored by the National Textile Center, a research consortium of eight universities, three North Carolina State University professors investigated the thermal stability of textiles, specifically with respect to the antioxidants used in the finishes.  They investigated four different antioxidants – one of which is based on Bisphenol A. (2)

So I got interested, and began a bit of poking around for other mentions of Bisphenol A in the textile industry. I found two scientific references to use of bisphenol A in the production of  polyester fabrics.  Both reported similar use of Bisphenol A as this quote,  which states:  “ a woven polyester fabric was … finished with an aqueous compound  containing 5% polyethylene glycol bisphenol A ether diacrylate for 30 min at 60° to give a hygroscopic, antistatic fabric with good washfastness.” (3)

I found that Bisphenol A is used  in the production of flame retardants, and as an intermediate in the manufacture of polymers, fungicides, antioxidants (mentioned above), and dyes.   Because it is often used as an intermediate it’s hard to pin down, and manufacturers keep their ingredients trade secrets so we often will not know – unless somebody funds a study which is published.

I have not seen any studies which report finding Bisphenol A in a finished fabric, so this may be a tempest in a teacup.  But isn’t it worth noting that this chemical, which has been found in the blood of 95% of all Americans, and which some say may be the “new lead”, can exist in products in which we previously never would have thought to look?

(1)  http://www.ourstolenfuture.org/newscience/oncompounds/bisphenola/bpauses.htm

(2) Grant, Christine; Hauser, Peter; Oxenham, William, “Improving the Thermal Stability of Textile Processing Aids”,  www.ntcresearch.org/pdf-rpts/AnRp04/C01-NS08-A4.pdf

(3)  http://www.lookchem.com/cas-644/64401-02-1.html?countryid=0