At picnic time, what do
we cover the potato salad with? Here's a casserole for the in-laws; what shall
we wrap it in? Stick the leftover dinner in the fridge but first cover it
with... As you might suspect, the solution in all the above situations is likely
to be Clear
Plastic Tube. Yes, this thin, clear plastic film has become an integral
part of our culinary preparations since it became publicly available in 1952.
Even though there's hardly an American who doesn't know what it is, almost no
one knows how plastic wrap is made. Read on to find out how chemical-laden
crude oil becomes food-grade plastic wrap. First, the most basic raw materials
are processed to make a suitable grade of plastic. This involves a lot of
heating, pressurizing, and the addition of LOTS of strong chemicals.
The end result is
granular plastic bits. These plastic granules are put into a boiler that heats
them melting point, which is between 200 and 400 degrees, depending on the
specific type of plastic being used. The liquid plastic is then forced through
a die that squeezes it out as a rope of warm, elastic plastic. As the tube is
squirted out, it is carried along a path lined with air nozzles. These air
nozzles are injected into the side of the tube of plastic and blow it into huge
bubbles much like we blow bubble gum. This blowing process stretches the
plastic to the necessary thinness of plastic wrap. The huge bubble is then
gathered up and fed between two rollers to make it into a film of plastic. The
film is then wrapped around a tube to make a gigantic roll.
Just one of the rolls
may easily hold enough plastic wrap to stretch over several miles. Next the
mega roll is unrolled and cut to fit the standard consumer-sized cardboard
tubes and boxes. This is usually a size of about 50 feet long by a foot wide.
Interestingly, all this rolling, unrolling, and re-rolling builds up a bit of
static electricity in the plastic. This charge is what make the clinging effect
of cling wrap. Once it is re-rolled on its final cardboard tube, the plastic wrap
is boxed, sealed, packed and shipped. The plastic wrap arrives at your local
store and you go in there, pick up a box, and take it home. There you have it.
This same plastic wrap has come all the way from bits of melting plastic to the
convenient wrap that plays such a major role in your everyday life.
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