Why does plastic wrap cling

Here, in a nutshell, are the two schools of thoughts on what makes plastic wrap stick. The act of peeling plastic wrap off a roll heaven help you if you lose the end of the film in the wrinkles on the roll , you create a static charge. The plastic picks up the charge, and since plastic bowls often have their own minutely negative charge, the positive charge in the plastic wrap makes it stick to the plastic bowl.

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. The Saran Brands website states the brand name wrap can be microwaved, but not heated in the oven. Unless stated on the product safe for oven or microwave, food plastic wrap is not recommended to be heated.

Untreated plastic wrap can release chemicals and melt when heated. Below is a video of food plastic wrap vs. A watt heat gun is used to heat the plastic wrap to show what happens. Pallet Length in. Pallet Width in. Pallet Diagonal Value in. Height in. Width in. Film width needed in. Frequently Asked Plastic Wrap Questions. Plastic granules are heated until they melt. The liquid is then forced through a die to form a tube of stretchable plastic. Compressed air is blown into the tubes to form a bubble.

The bubble stretches the plastic into the desired thicknesses. The bubble is collapsed between metal rollers to form a plastic film. The film is then rolled onto a large metal roll that may hold several kilometers of film.

From the large roll, the plastic wrap is unwound, cut, and rerolled onto smaller rolls. The rolling and unrolling of the plastic wrap help to provide more cling. The rolls are then placed into cardboard containers with serrated edges or packed individually for the end-user. Pallet Diagonal Calculator Enter the correct measurements per label. Some plastic wrap is hydrophilic, grabbing on to any water it gets close to.

Some is hydrophobic, repelling water. Water, unless it's pure, also conducts electricity. Plus, all wraps wad up like dirty laundry, or stick on like burrs. If static electricity made them work, they would sometimes be repelled by themselves, or other substances. That would make them impractical to use. It's materials science, not electric charge, that gives cling wrap its clinginess.

Most cling wrap is made of one of two materials; polyvinyl chloride or low-density polyethylene. Both of these are long polymers - chains of molecules. These chains cling to each other very well. In fact, the polymers in polyvinyl chloride are so bound together that they do not let water or air get through them. The military used to spray "Saran," the early name of the chemical, on fighter planes to prevent corrosion.

It was also used in upholstery.