Introduction

What is Plastic Wrap?

Plastic wrap, also known as cling film, Saran wrap, or cling wrap, is a versatile packaging tool used for both industrial and domestic purposes. It is a thin, transparent plastic film that clings to itself and food containers to create a tight seal. Plastic wrap is primarily used to preserve the freshness of food by protecting it from air, moisture, and odors. It is widely used in the food industry, as well as in households, to extend the shelf life of various food items.

The Evolution of Plastic Wrap

The history of plastic wrap dates back to the early 20th century. In 1933, a lab worker at Dow Chemical Company accidentally discovered the key chemical used in plastic wrap while trying to clean beakers used in the development of a dry-cleaning product. This chemical, known as polyvinylidene chloride (PVDC), was initially used as a spray to protect fighter planes and other military equipment from water. In 1949, Dow Chemical introduced Saran Wrap, a commercial plastic wrap made from PVDC, which quickly gained popularity for its ability to preserve food items stored in the refrigerator.

The Ingredients of Plastic Wrap

Plastic wrap is primarily made from two main ingredients: polyethylene and polyvinylidene chloride (PVDC). Traditionally, plastic wrap was made from PVDC, which provided exceptional cling properties and a high barrier to oxygen, water vapor, and flavor molecules. However, due to environmental concerns and potential health risks associated with the chlorine content of PVDC, manufacturers transitioned to using polyethylene in the production of plastic wrap. Polyethylene is a safe and microwave-safe material that offers sufficient cling and preservation properties for most household applications.

Manufacturing Process

Processing the Raw Materials

The production of plastic wrap involves the processing of raw materials such as polyethylene and PVDC. Polyethylene is derived from simple hydrocarbons, while PVDC is synthesized from vinyl chloride and vinylidene chloride. The raw materials are obtained from petroleum or natural gas through various refining processes.

Polymerization

Polyethylene is polymerized from ethylene, which undergoes a process of heating and pressurization in the presence of oxygen. This process creates free radicals that combine with each other to form chains of polyethylene. PVC and PVDC are polymerized from vinyl chloride and vinylidene chloride, respectively, in a similar manner.

Formulation and Packaging

Once the polymers are formed, they are processed into thin films using extrusion techniques. The films are then cut into appropriate sizes and packaged into rolls or boxes for consumer use.

Types of Plastic Wrap

Polyethylene Plastic Wrap

Polyethylene is the most common type of plastic wrap used in households. It is a safe, microwave-safe material that provides sufficient cling and preservation properties for most food items. Polyethylene plastic wrap is versatile, affordable, and easy to use. It can cling to itself and food containers, creating an airtight seal to keep food fresh.

PVDC Plastic Wrap

PVDC plastic wrap, also known as Saran Wrap, was the original type of plastic wrap introduced by Dow Chemical in 1949. PVDC offers superior barrier properties, including high resistance to oxygen, water vapor, and flavor molecules. However, due to environmental concerns and potential health risks associated with the chlorine content of PVDC, its use in plastic wrap has been phased out in favor of polyethylene.

Applications of Plastic Wrap

Food Preservation

The primary application of plastic wrap is to preserve the freshness and quality of food. By creating an airtight seal, plastic wrap helps to protect food from air, moisture, and odors, thereby extending its shelf life. Plastic wrap is commonly used to wrap leftovers, fruits, vegetables, sandwiches, and other perishable food items.

Food Service Industry

Plastic wrap plays a crucial role in the food service industry. It is used by restaurants, catering companies, and other food establishments to wrap and store food items for later use. Plastic wrap helps to maintain the hygiene and freshness of food during transportation and storage, ensuring that it reaches the customers in optimal condition.

Industrial Packaging

In addition to its use in the food industry, plastic wrap is also used for industrial packaging purposes. It is commonly used to wrap and protect pallets, boxes, and other bulk items during transportation and storage. Plastic wrap provides a secure and protective barrier, preventing damage and contamination of industrial goods.

Safety Considerations

Microwave Use

When using plastic wrap in the microwave, it is essential to follow the manufacturer’s instructions. Plastic wrap made from microwave-safe materials, such as polyethylene, can be safely used in the microwave for short periods. However, it is crucial to prevent the plastic wrap from touching the food directly to avoid potential melting or the release of harmful chemicals.

Contact with Food

To minimize potential risks, it is recommended to avoid direct contact between plastic wrap and fatty foods during heating. This is especially important for commercial plastic wraps made from PVC, which may contain additives such as plasticizers that can migrate into the food under certain circumstances. When defrosting meat in the microwave, it is advisable to remove it from the plastic wrap or trays to prevent any potential chemical migration.

Environmental Impact

Plastic wrap, like other plastic materials, contributes to environmental pollution and waste. It is important to dispose of plastic wrap properly and consider alternative packaging options whenever possible. Recycling programs for plastic wrap are available in some areas, and using reusable containers or biodegradable wraps can help reduce the environmental impact of plastic waste.

Choosing and Using Plastic Wrap

Selecting the Right Plastic Wrap

When choosing plastic wrap, consider your specific needs and preferences. Look for plastic wrap made from microwave-safe polyethylene for household use. If using plastic wrap for commercial or industrial purposes, ensure that it meets the necessary safety and quality standards.

Proper Usage Tips

To use plastic wrap effectively and safely, follow these tips:

1. Leave a corner of the dish uncovered when microwaving to allow steam to escape.
2. Avoid direct contact between plastic wrap and fatty foods during heating.
3. Consider using alternative coverings, such as unprinted paper towels or microwave-safe containers with removable lids.
4. When storing food in the refrigerator, minimize contact with plastic wrap by using containers or bags specifically designed for food storage.
5. For long-term storage in the freezer, opt for containers or bags designed for freezing rather than using plastic wrap.

Conclusion

Plastic wrap is a versatile packaging tool that serves various purposes in both domestic and industrial settings. It helps preserve the freshness and quality of food, ensuring that it remains safe for consumption for an extended period. By understanding the types of plastic wrap available, their manufacturing processes, and proper usage guidelines, we can make informed choices to promote food safety and minimize environmental impact. Remember to choose the right plastic wrap for your needs, follow safe usage practices, and consider alternative packaging options whenever possible to reduce plastic waste.