Shrink Wrap, Stretch Wrap, Saran Wrap—What’s the Difference?

Look, we understand—it happens all the time. When you’ve never heard of a company providing shrink wrapping service before, the first thing you think of when someone says “shrink wrap” is that thin, transparent, plastic material that you might wrap around a sandwich or stretch over the lid of a Tupperware container. And when someone starts talking about shrink wrapping boats, or cars, or helicopters, or cranes, you can’t help but wonder, “What in the world is this person talking about? How and why would you shrink wrap a boat?”

We sympathize, and we can explain. The material you’re probably used to seeing in the kitchen is just one of many kinds of plastic wrap made from different wrapping material with different application methods for a wide variety of purposes. Here’s a breakdown of the different kinds of plastic wrap, what they’re made of, and how they’re used.

Types of Plastic Wraps

The first distinction that needs to be made is that between shrink wrap and other kinds of plastic wrap. Many people mistakenly use the term shrink wrap to interchangeably refer to shrink wrap, stretch wrap, cling wrap—any kind of tight plastic covering, really. But this isn’t an accurate usage of the word.

The type you’re probably most familiar with is cling wrap, also known as saran wrap, food wrap, and more generally (and confusingly, in the context of this discussion) as just plastic wrap. Saran was first developed by Dow in the 30s and sprayed onto fighter planes to protect them from the corrosive effects of seawater spray, as well as being used in car upholstery. After the war, it was developed into the rolls of film that you may use in the kitchen. It’s made traditionally from polyvinylidene chloride, or PVC, though in recent years that material has started being replaced with low-density polyethylene, LDPE.

There also is sometimes confusion between shrink wrap and stretch wrap. Stretch wrap sort of bridges the gap between shrink wrap and cling wrap. Stretch wrap is usually made from polyethylene plastics and, as you can probably guess, is very stretchy, allowing it to be wrapped tightly around large objects. That makes it easy to secure groups of objects together for transport on a pallet, as well as protect them from dust and moisture. It can be wrapped around the products manually with a roller, or with a machine that performs the task automatically.

Shrink wrap is neither cling wrap nor stretch wrap. It can be made from a variety of plastics including PVC, polyethylene, and polyolefin. It’s applied around an object a bit loosely and then heat is applied to make it shrink and conform tightly to the shape of the object. Heat can be applied through a variety of means depending on the type of wrap, size of the object, and scope of the operation. Some methods include heating with a heat gun, in a machine that passes it through a shrink tunnel, or in an oven.

Shrink Wrap Materials

Shrink wrap can be made of several different kinds of plastics, which play a large role in determining what sorts of applications it can be used for.

Shrink film made from PVC is the cheapest form and is commonly used in a lot of lightweight retail packaging, often enclosing boxes containing CDs and DVDs, soap, candles, and more. Because PVC contains chloride though, it can’t come into direct contact with food. Industries often use it because it’s affordable and versatile.

Polyolefin, however, is starting to replace PVC. While it’s more expensive, it holds up better in a wider range of temperatures, becoming neither brittle and hard in the cold nor crinkled and sticky in the heat. The seal is also more durable. These factors contribute to protecting companies against potential losses. It’s also FDA approved for contact with food.

Another material available for shrink wrapping service is polyethylene. This is the thicker, stretchier shrink wrap that you may most commonly see bundling together water bottles in the grocery store. Along with polypropylene, it’s also the kind of shrink wrap used by companies like ours to wrap large objects and winterize boats.

Commercial shrink wrap material can also be modified for specific purposes. It can be UV protected, flame retardant, or have antimicrobial treatments that protect wrapped objects from mold and mildew. It can even be made with volatile corrosion inhibitors (VCIs) to keep equipment within from corroding without the use of grease or wax.

Shrink Wrapping Service and Application

Aside from materials, there are also various formats and applications for shrink wrap.

Centerfold shrink wrap is folded in half before being put on a roll. That way, as you roll it out there are two sheets, and you simply place the product between the two, seal the edges, and apply heat. This application typically has PVC or polyolefin materials but can be made of polyethylene as well.

Shrink sleeves are often placed over containers such as plastic bottles and have all the branding and whatnot printed right on. These typically can’t shrink as much to keep the words from being distorted, but allow for complex designs. Shrink banding similarly conforms around the cap of many medicine and toiletry bottles to create a safety seal.

Shrink tubing and shrink bags offer ways for a product to easily be sealed and shrink wrapped with minimal effort. A shrink tube is a continuous roll so that objects can be placed within, the wrap cut and sealed, and heat applied. It’s similar to centerfold wrap, but with two less sides to seal, at the cost of often being narrow and thus more suited for long narrow objects. A shrink bag is a similar concept but with one less edge to seal—it simply is a bag that an object is placed inside before the opening is sealed and heat is applied.

Industrial shrink wrapping service is distinct from those other types, but by now you’ve likely gotten a good grasp of the basics common to all shrink wrap. Companies like ours that offer shrink wrapping service for commercial applications commonly offer boat winterization as a main draw, but we also can shrink wrap any sort of large machinery, vehicles, scaffolding, furniture—you name it. Anything that needs to be transported, stored, or protected from moisture and other elements for a prolonged period, shrink wrapping service can keep in top condition.

If you have something in mind that could benefit from this sort of shrink wrapping service in McHenry, Unlimited Shrinkwrap is the experienced service provider you need. Just give us a call at (815) 759-8944 and our experts will consult with you about the needs of your particular project.

Whatever you’re looking to shrink wrap, we’ve got you—and your possessions—covered.

Unlimited Shrinkwrap
2350 W. Rte. 120
McHenry, Il 60051
(815) 759-8944