About the only thing I remember from high-school chemistry is the vivid blue you get when you add copper sulfate crystals to water. Had the teacher explained all those chemical compounds and heat-induced reactions in terms of common household materials, I would have been a lot more interested, and decades later I’m sure I would remember more than just one color.
For example, aluminum compounds are central to the manufacture of plastic laminate and solid surface countertops.
In the case of plastic laminate, aluminum oxide particles, which are almost as hard as diamonds, provide durability and toughness. In fact, the more aluminum oxide in the mix, the more scratch resistant the wear surface becomes. Curiously, this same compound is also an important ingredient of sand paper, which is highly abrasive.
The aluminum oxide, so finely ground it is invisible to the naked eye, is mixed with a plastic melamine resin to form the topmost of plastic laminate’s three layers. This layer functions like protective glass in front of a painting. The second layer – the painting, so to speak – is a clear plastic sheet that has a color or pattern printed on it. Together, the top layer and the “painting” are a mere 5/1000’s (five one-thousandths) of an inch thick. The bottom layer, which gives plastic laminate its rigidity, is made up of phenolic-resin soaked sheets of brown paper, which resembles grocery bags. When the three layers are placed in a press, the high heat and pressure fused them together.
The printing process that creates the colors and patterns for plastic laminate has become so sophisticated that many laminates look exactly like the materials they are mimicking, such as marble and granite, unless you look closely. Others mask scratches so well that they seem to disappear. Despite all these advances, however, plastic laminate is not actually scratchproof or stainproof so you need to use a cutting board and clean up spills promptly.
The sophisticated printing process has also created such a surfeit of choices that many homeowners find making a selection daunting. Wilsonart now offers 278 colors and patterns, and Formica has 252.
The major ingredient of solid surface countertops such as DuPont’s Corian and Wilsonart’s Gibraltar is another aluminum compound, aluminum trihydrate.
To make the countertop the aluminum compound is mixed with a petroleum-based, acrylic resin binder, and a catalyst such as peroxide (much stronger than the stuff you put on your hair) is added to start hardening or “curing” the countertop.
The curing process is analogous to making a cake, where you mix wet and dry ingredients, put the batter in a hot oven and finish making dinner while a series of chemical reactions create a new material, i.e. a cake. Just as you can mix in the chocolate chips or chopped nuts to give variety to a cake, small granules of ground-up solid surface or other materials can be added to the countertop mix to produce a flecked look that mimics natural materials such as granite and marble.
When “cooking” solid surface ingredients, the acrylic binder starts as a small molecule, but as it heats up the molecules combine to form long polymer chains (this process is called polymerization). These in turn form a lattice-like structure that holds the aluminum trihydrate in the material.
A wide variety of solid surface colors are available, though not as many as plastic laminate. Corian currently offers 110 and Wilsonart offers 69.
Shetkastone, another solid surface countertop material, uses an entirely different process that recycles plant, cloth or paper fibers. Each type of fiber is pulped with water to create an oatmeal-like goo. The mix is placed in a mold and pressurized. As it dries, the fibers that became interlocked with the pulping shrink up and become even more interlocked, so that even repeated hammering can’t break them apart (this process is called hydrogen bonding). Unlike other countertop materials, Shetkastone can be endlessly recycled. When a Shetkastone countertop reaches the end of its useful life, it can be repulped and recast as a countertop or as any of the other items that Shetkastone currently makes, including desktops and window sills.
Shetkastone offers 7 different countertop colors with names that reflect their origins – Publisher Grey (newspaper), Latte (cardboard), and Counterfeit Green (shredded U.S. dollar bills donated by the Minneapolis Federal Reserve Bank, which wanted an environmentally benign way to deal with its paper waste).
Richlite countertops are made with 10 percent recycled paper, which is soaked with phenolic resin and laminated together under heat and high pressure. The manufacturing process and the product are similar to the backing for plastic laminate, but in this case the papers are colored and many more are used – to be precise, 210 sheets are needed to make a countertop that is 1-inch thick, extremely hard, scratch and stain resistant, and easily cleaned. It requires sealing every one to two years, depending on how aggressively you scrub it when cleaning.
Only about 10 percent of the paper used in Richlite is recycled because any more than this would compromise the structural integrity of the finished product, said Richlite’s president Doug Baum, who went on to explain that with recycled papers, bits of plastic wrapping can never be entirely removed and this adversely affects his particular product. Richlite is very hard, stain and scratch resistant, and easily cleaned. It requires sealing every one to two years, depending on how aggressively you scrub it when cleaning.
In addition to six richly saturated colors made with wood-based paper, Richlite offers a honey brown made with hemp-based paper. The particular hemp plant used, called abaca, is a close relative of the banana tree, not the variety that can be smoked.
The company has been active in the residential market since 2000, but Richlite has been widely used for food preparation tables in restaurants for more than 40 years.
With engineered stone countertops, known to most consumers by trademarked names like Zodiaq, Silestone and Caesarstone, chemistry transforms a mineral with great characteristics at the micro scale into one that makes great countertops. Crystallized silicon oxide, or quartz, is very hard, durable and readily available nearly everywhere on the planet, but not in pieces large enough to make a countertop (or even a floor tile). But, when it is pulverized, mixed with a small amount of polyester binder, heated and compressed, however, a very hard man-made material with a wonderful luminosity is created. It is difficult to scratch and, unlike many natural stones such as marble and granite, it is highly stain resistant, and it doesn’t require periodic sealing.
All the companies that make engineered stone use the same patented manufacturing process, which is owned by Bretton, an Italian firm. As one would expect with many chefs using the same recipe, manufacturers tweaks their product in their own way and produce differing results. The chefs have also taken advantage of quartz’s amazing flexibility. It can be ground and colored to mimic real stones such as granite and marble. It can take on any color and it can be polished to a variety of finishes including high gloss, honed (offered only by Caesarstone) or a matte-like leather (offered only by Silestone).
Homeowners considering engineered stone have many choices, though the total number is not as overwhelming as with some other materials. Zodiaq offers 36; Caesarstone, 40; and Silestone, 50.
Web site information:
- Plastic Laminate
- Paper Laminate
- Solid Surface
- Engineered Stone
Questions or queries? Katherine Salant can be contacted at www.katherinesalant.com.
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