Procedures (First Draft)

Procedures:

Evaporation:

1.      Add Liquid to beaker at approximately ______ml and record how much was put in.

2.      Put plastic wrap over each beaker.

3.      Repeat steps 1-2 for each plastic wrap (4 wraps).

4.      Repeat steps 1-3 for each liquid (3 liquids).

5.      Each day check the rate of change of the liquids (in ml).

6.      After a week, measure the liquid (in ml).

7.      Record the amount of liquid in the beaker.

8.      Find the rate of change.

9.      Repeat steps 5-8.

Oxidation:

1.      Place an apple on a cutting board.

2.      Cut the apple into four equal pieces.

3.      Place apple in Tupperware.

4.      Cover Tupperware with the plastic wrap.

5.      Repeat steps 1-4 for each plastic wrap.

6.      Continuously monitor the apple through the day.

7.      After one day, measure the brownness of the apple on a visual scale.

Abstract (Before Experiment)

Abstract

This project is testing which of four plastic wraps (PVC, PVdC, LPDE, and Press and Seal wraps) prevents oxidation (on a visual scale) and evaporation (in ml) the best. Oxidation is the chemical reaction in which an atom of an element loses one or more of its electrons to a different atom. Evaporation is the change of water from liquid to gas.

Problem

Which of four plastic wraps (PVC wrap, PVdC wrap, LPDE wrap, and press and seal wrap) will be the most effective against oxidation and evaporation?

Materials

·         PVC Wrap

·         PVdC Wrap

·         LPDE Wrap

·         Press and Seal Wrap

·         4 beakers

·         Water

·         Window cleaner

·         Vinegar

·         4 plastic containers

·         4 Apples

·         Visual Scale

·         (The rest is yet to be determined)

Variables

The independent variables are the types of plastic wraps that are being tested. The dependent variables are the measurement of evaporation (in ml) and the amount of oxidation (on a visual scale of 1 to 10). The constants are the temperatures of the liquids being tested in the evaporation section and the apple slices in the oxidation section. The control is measuring the oxidation of the apple and/or the evaporation of the liquids without the wraps in the temperature of a refridgerator.

Hypothesis

Press and seal wrap will be the most effective against oxidation and evaporation. Research shows that this wrap has a special gum-based sealant that creates a perfect seal when pressed correctly. The seal creates a barrier that does not let any liquids or air in or out. This increases the length of time that the food or liquid stays fresh. The gum-base also prevents the food from becoming toxic, that some plastic wraps have in their sealants. However, the sealants in press and seal wrap are not toxic. Therefore, the food will not become toxic when wrapped in press and seal wrap.

LDPE wrap will be the second most effective against evaporation and oxidation. Research shows that the wrap’s sealant has low peeling probability, keeping food non-toxic. LDPE wrap is the most common wrap that can be found in stores. Some of the brands include: Glad Cling Film® and Saran Premium®. This wrap is also more ecologically acceptable because it does not have chlorine in its molecules.

PVdC wrap will have a consistently good average against oxidation and evaporation. Research shows that this wrap has high clinging ability and adhesive purposes. It also has a low permeability to liquids, but it loses some liquid due to condensation. The wrap preserves the food’s aroma and some of its freshness. However, it will not keep the food fresh as long as some other plastic wraps.

PVC wrap will be the least effective against oxidation and evaporation. Research shows that PVC wrap is mostly used in food catering for short periods of time. The wrap is not usually used for long lengths of time. The wrap is also is excessively clingy, that the fibers can peel off when not applied correctly. This makes the food toxic.

Plastic Wrap Info

This is a list of the plastic wraps and their chemical/physical quantities about them:

• PVC Wrap: PVC is an acronym for polyvinyl chloride, its chemical name. Plastic wraps that are made of PVC are called PVC wraps. The films in PVC are used for catering purposes. These films are useful because they make for visual appeal by instantly clinging on to most surfaces of foods. Unfortunately, the films can compress to the food too much and stick to the food, making the food toxic. PVC wrap was the first wrap ever made in the world. (http://www.ehow.com/)
  

  

  
  

• PVdC Wrap:PVdC is an acronym for its chemical name: polyvinyledene chloride. PVdC wrap is exclusively used for its adhesive purposes. It is also known for impermeability to air and fluids. The aroma of the food lasts longer when reopened after is has been stored either in the freezer or refrigerator. PVdC wrap is also known as saran wrap. (http://www.ehow.com)
  

  

  
  

• LDPE Wrap: LDPE is an acronym for low-density polyethylene. It is known for cling-wrapping food. LPDE wrap is the most common wrap in this era. Name brands that use this wrap include: Saran Premium, Glad Cling Films, and some other common brands. This wrap has, unlike the others, a low clinging ability/adhesion. Despite this fact, it is accepted as a higher-quality product because of its absence of chlorine in its molecules. The food still is freezer safe and microwavable, though. (http://www.ehow.com/)
  

  

  
  

• Press and Seal Wrap: Press and Seal Wraps are a new and upcoming form of wrap. It uses a special gum-based sealant that creates a perfect seal. The gum-based formula is edible if the films peel off on the food, preventing the food from being toxic. However, the films must be pressed and closed in order to be sealed (e.g. the name of the kind of wrap). This wrap uses special waves of films that flatten when pressed. Press and seal can prevent food from dehydration or freezer burn. The food that is wrapped in this is microwavable. (http://www.ehow.com/)

Experiment Starting Soon

My experiment should start soon! It may not be this weekend, but the next weekend. My family and I are moving this weekend into a new house. Barring any problems, it should get done soon!