SANDWICH WRAP By: Shannon, Karina and Amel

Introduction Sandwich wrap (also known as plastic wrap) is used for many things throughout our daily lives. It easily wraps anything and seals itself so that nothing can get in the way, without almost any help… but have you ever thought why? Why is it that its attracted to almost everything, including itself? Is there a trick behind it, or is it just static electricity… In this PowerPoint, we will show you what’s really behind it all with a few pictures, some examples and a video. We hope you enjoy!

WHAT IS IT USED FOR?

Our commercial for sandwich wrap ! STARRING: Amel Bouanani Shannon Ford Karina Makarova GUEST STAR: Sara Parker

Plastic wrap is used… ■To keep food fresh by protecting it from air. ■To prevent dry foods from absorbing moisture and wet foods from losing moisture. ■To seal in food odor – preventing it from spreading to other foods near by. ■To keep sandwiches/messy foods in place (within the wrap).

WHY DOES SANDWICH WRAP CLING?

Why does it cling to other objects? ■Mainly, sandwich wrap clings because of the fact that it’s elastic and sticky. Plastic wrap is attracted to any object with an opposite charge, which is why it clings to almost anything. ■For example, if the sandwich wrap is neutral, it would automatically cling to anything else that is charged (no matter, positively or negatively).

Why does it cling (scientifically)? ■Another reason why plastic wrap clings is because of its molecular structure. A molecule of plastic is very long and coils up when you stretch it out. ■When you release the sandwich wrap, you’re releasing the molecules of plastic which make them bounce back. That’s why when you cover a container with sandwich wrap, it springs back and tucks under the rim of the bowl.

Why does it cling to itself? ■Plastic wrap clings to itself because it easily picks up a static electric charge caused by friction. ■The friction causes the electrons to move to one side of the plastic wrap (which gives it a negative charge), then the protons to the other side (giving it a positive charge). So because of the opposite charges on each side, the plastic wrap ends up clinging to itself.

CONCLUSION

QUIZ TIME!!! ■Groups of 2 (at each table) ■First pair to raise their hands simultaneously (AFTER question is asked) will be chosen to answer ■Right answer gets a point, wrong answer goes to the pair to raise hands second ■Group with most points wins! ■Good Luck!

Question #1 List 3 things plastic wrap can be used for

Question #2 What 2 words describe plastic wrap?

Question #3 Why does plastic wrap cling?

Question #4 What makes plastic wrap stretchy and bounce back underneath the rim of a bowl?

Question #5 Why does plastic wrap cling to itself?

Question #6 What causes the electrons to move throughout the plastic wrap?

BONUS QUESTION #7 List 3 things that are COMMONLY wrapped in plastic wrap

LAST BONUS QUESTION In what way does plastic wrap protect the foods inside it?

Thank you for listening! For our opinions on if its necessary, visit our blogs: Karinam2015 Shannonf2015 Amelb2015 We hope you learned a bit about sandwich wrap!

Resources: Wrap.html ce/plastic-wrap-cling