What makes plastic wrap sticky

Cling wrap, plastic wrap, Saran Wrap — no matter what you call it, or what brand it is, the clear adhesive plastic has been a staple in households for decades. Its ability to preserve and seal has been revered by the food industry, auto industry, and even the U. There's a reason for that — and it has nothing to with saving money. T he original wrap contained a chemical that's toxic to the planet. Polyvinylidene chloride, or PDVC, is the polymer in plastic wrap that makes it stick to itself so well.

It also keeps odors in and is microwave-safe. What makes kitchen plastic wrap cling so maddeningly to itself, and so conveniently to the sides of bowls and plates?

Plastic wrap clings for two reasons: it's elastic and it's sticky. That probably seems pretty obvious, but let's explore the chemistry beneath the elasticity and stickiness of plastic wrap. Plastic wrap is elastic because of its molecular structure. A molecule of plastic is incredibly long and coiled up like a spring.

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Or so the theory goes. The problem with the static-cling argument is that plastic wrap also clings just as well to metal and glass, two materials that conduct electricity and would thereby eliminate any difference in charge between the bowl and the wrap — and any stickiness. In fact, plastic wrap actually clings better to glass and metal than it does to plastic!