There’s this place where I live called “Jimmy’s Food Store” and it is, as you might expect, a store where food is sold.  But oh what food it is!  Italian comestibles dripping with Italian deliciousness, sold with Italian gusto to Italians and non-Italians alike.  At Jimmy’s Food Store you can get an Italian meatball sandwich that will bring tears to your eyes. You will literally be crying as you eat it because it is so tasty, and you’ll be crying after you’ve eaten it because you’ll be so sad it’s gone.  I just started crying quietly at my desk just because I am thinking about it, actually.

If there is a drawback to Jimmy’s meatball sandwich (and please note that when I say drawback this is like pointing out that Miss Universe had on one too many fake eyelashes at the last pageant) it is that you receive it in a Styrofoam container.  I remember learning that it takes something like nine billion years and a thermonuclear explosion for Styrofoam to break down and return to Earth, and that even as it does so it is poisoning things and wreaking havoc and stealing your purse at gunpoint. It is bad stuff.  And even if you accept the fact that it has some good points (is a cheap insulating material that basically lasts forever) the Styrofoam containers at Jimmy’s are evil because they MAKE THE SANDWICH A LITTLE BIT SOGGY IF YOU DON’T OPEN IT RIGHT AWAY.

Image courtesy ecolect.net

I starting thinking about this while eating lunch at Jimmy’s last week because I had come across information about PaperFoam, which is an injection-molded cellulose fiber-based packaging material.  Paper foam is itself made from recycled paper, and its properties are similar to thin Styrofoam or pulp in packaging applications.  According to Ecolect, “the product is extremely lightweight which lowers the transportation costs, and consumers can discard [it] with paper recycling or in the trash as it easily biodegrades…  PaperFoam CD packaging, for example, has an 85% lower carbon footprint compared to traditional, plastic jewel-case CD packaging.”  The product is produced in the Netherlands, Denmark, the United States and Malaysia.

So I am thinking that Jimmy’s needs to develop a PaperFoam extra special vented meatball sandwich container. It would be biodegradable, prevent the sandwich from getting soggy, and keep it warm at the same time due to its insulating properties.  And for those of you wondering how this is relevant to architecture – you can’t build anything on an empty stomach!

WU XING

I have filed this material under WOOD because it is made of tree fibers.

Cited:

“Check Out Paper Foam, an Amazing Material!” Ecolect.net. Accessed 10/5/11. URL.

Image courtesy www.aqua-velvet.com

Foam does more than cushion the inelegant landings of would-be circus performers; we use it to pad furniture, for insulation, packaging, and miscellaneous other products, such as foam-coated wire hair curlers that resemble play-doh spaghetti.  While we love foam because it’s light-weight, absorptive, insulating, and so on, the manufacturing process is energy-intensive and an awful lot of it winds up accumulating in landfill. 

In response to the problem, scientists have developed an “ultra-light biodegradable foam plastic material made from two unlikely ingredients: The protein in milk and ordinary clay” (Physorg.com).  Before you go out and throw some pottery shards in your 2%, let me explain how this works.  Nearly all of the protein in cow milk is casein, and we already use it in an industrial setting to make adhesives and paper coatings.  The substance is not particularly strong and it’s water-soluble, so to “beef up” the casein and increase its water resistance the researchers “blended in a small amount of clay and a reactive molecule called glyceraldehyde, which links casein’s protein molecules together” (Physorg.com).

Powdered casein courtesy www.spectrafix.com

The resulting mixture was promptly freeze-dried, producing a “spongy aerogel, one of a family of substances so light and airy that they have been termed ‘solid smoke.’  To make the gossamer foam stronger, they cured it in an oven, then tested its sturdiness. They concluded that it is strong enough for commercial uses, and biodegradable, with almost a third of the material breaking down within 30 days” (Physorg.com).  You can read more about aerogel here.

Images courtesy Biomacromolecules

The biodegradable foam could find a use as a packing material or as a protective coating that degrades after a period of time to reveal a different material underneath.  I suppose you could also shoot it out of a circus cannon but I’m not sure the Ringling Brothers would be keen about it.

WU XING:

I’ve filed biodegradable foam under earth because it’s made with clay!

Cited:

“Development of Biodegradable Foamlike Materials Based on Casein and Sodium Montmorillonite Clay.” Tassawuth Pojanavaraphan, Rathanawan Magaraphan, Bor-Sen Chiou, David A. Schiraldi. Biomacromolecules 2010 11 (10), 2640-2646.

“Biodegradable Foam Plastic Substitute Made from Milk Protein and Clay.” Physorg.com 10/20/10. Accessed 11/16/10. URL

Image courtesy wikimedia.org

Any kind of metallic material that contains voids can be classified as metal foam.  There are two distinct types: open-cell and closed-cell structures. The key difference between the two structures is that open-cell foams are permeable and will allow fluids to pass through the foam whereas closed-cell foams are impermeable (Metafoam).  I found this handy description that further characterizes the different species of metal foam by John Banhart (Source: Metal Foam Info).

• cellular metal: space is divided into distinct cells. The boundaries of these cells are made of solid metal, the interiors are voids. Ideally, the individual cells are all separated from each other by metal but often this restriction is relaxed.

• porous metal: the metal contains a multitude of pores, i.e. closed, curved gas voids with a smooth surface.

• metal(lic) foam: foams are special cases of porous metals. A solid foam originates from a liquid foam in which gas bubbles are finely dispersed in a liquid.

• metal sponge: space is filled by pieces of metal that form a continuous network and co-exist with a network of empty space which is also interconnected.

Metal foams are great because of their massive surface area; they’re light because they consist mostly of air; they’re tough and can resist high temperatures, corrosion and humidity depending on what metals are foamed; they’re stiff and ductile and can absorb impact energy; they can be recycled.  The downside is that metal foams are difficult to produce (by which I mean they are completely expensive and plagued by quality control issues).

Image courtesy frostytech.com

Metafoam manufactures open-cell metal foam for industrial electronics cooling and other applications.  They’re working on producing copper foams to replace the current copper powder-based wick structures used in heat pipes and vapor chambers, developing products that “have up to 100 times more specific surface area (20,000 m²/m³ on average) than typical metallic foams. This represents more than 3 football fields of surface in a single cubic meter” (Metafoam).  I love it when you can measure something in football fields.

What caught my eye about Metafoam was the extensive focus on “green” or “sustainable” manufacturing practices.  We use a LOT of copper in the construction industry – especially in mechanical, electrical, and plumbing systems.  The large surface area of a foam structure allows efficient heat transfer with much less material, and that saves energy.  Any time you can use less of something you’re better off, but some of the statistics Metafoam provided in their product information surprised me.  I don’t know if it’s true, but they assert that for every ton of copper they don’t have to use to manufacture a certain amount of metal foam, they save 22.0 cubic meters of fresh water.  Using less material also tends to reduce SO2 emissions in the smelting stage of copper metal processing, and less sulfur releases into ground and surface water that during mining and tailing.

Cited:

Banhart, John. “What are Cellular Metals and Metal Foams?” Metal Foam Info. Accessed 02/19/10.  URL.

Heon-Cheol Shin and Meilin Liu. “Copper Foam Structures with Highly Porous Nanostructured Walls.” Chemistry of Materials 11/07/04.  Accessed 02/19/10.  URL.