To start with, what is shrink film actually? Imagine you are in a landlocked place and want to eat fish. You go to a store and buy a pack of fish. But how the fish that is caught hundreds of miles away from your place, wrapped in a packet is still fresh to eat? Well, thanks to the brilliant packaging option called the Shrink Film, also known as shrink wrap!
How does it work? Shrink film is an adaptable material made out of polymer used in packaging goods. When the products are wrapped with the film and heat is applied to it, the film shrinks tightly around the item. As a result, the item will have a barrier of protection around it from outside materials.
Now there are different kinds of shrink films – Polyolefin shrink film (POE), Polyvinyl Chloride (PVC), and Polyethylene films (PE). But before we talk in detail about them, we’ll look at the various the characteristics of shrink films and how the packaging industry benefits from this. Let’s dive in.
Considerations of shrink films you must be aware of:
1. Shrink Force (Measurement)
Shrink Force is essentially the measurement of the amount of force exerted by the shrink films on the products. The shrink force varies from one shrink film to another. Polyolefin shrink film (POE) has high shrink force while the Polyvinyl Chloride (PVC) exerts a low amount of it.
This is basically the physical alignment of shrink films. The two major orientations they come in are bi-axial and preferential. Bi-axially oriented shrink films typically shrink equally along both the horizontal and vertical directions while preferentially oriented shrink films shrink in a specific direction.
3. Shrink Percentages
Shrink percentages can be altered when preferentially oriented films are used. If you chose to use bi-axially oriented films, this can still be achieved by lowered and continues to use these films.
4. Puncture and Tear Resistance
A measurement to find out the level of resistance a shrink film has towards possible breakage or tears after a puncture. A film with high resistance to puncture will have high resistance to tear and conversely, a film with low resistance to tearing will have lower resistance to puncture.
5. Moisture Measurement
The measurement of the amount of moisture passing through the package is called the moisture vapor transmission rate (MVTR). Depending on the required moisture transmission, you can alter the MVTR.
A very important quality check for packagers is minimizing or eliminating fog build-up from the packages. Anti-fog films can ensure there is no fog inside the packages, especially for food items.
7. Odor Blocks
Films that block bad smell to enter the packages ensure customers receive products that look and smell fresh. You don't want your customers getting packages that release bad stench.
Now that you know what is a shrink film and some important characters of them, let us look at different types of films available and their advantages.
Different Types of Shrink Films
1. Polyvinyl Chloride (PVC) Shrink Films
During the earlier days of shrink films in the packaging industry, and for a very long time, PVC was the most popular and widely used shrink film in the world. However, because of various health hazards in the process of creation and disposal of PVC, new types of shrink films Polyethylene and Polyolefin shrink film have come into existence. The PVC has enjoyed less popularity since then.
Main Characteristics of PVC
-Harmful chemicals and environmentally unviable
PVC has dangerous chemical composition unsafe by-products during decomposition which lead to its reduced usage. They are now mainly used in construction and related materials packaging.
-Sensitive to temperature changes
PVC is cannot withstand certain high and low temperature. Also, its lower resistance to punctures has made it the least preferred shrinking film.
-Not highly recyclable and delicate
PVC is the least recyclable compared to other types of shrink films. The other negative characteristic is its fragile nature. Due to this, PVC is not ideal for packing multiple items together.
Polyolefin (POF) Shrink Films
POF films are the most versatile of all the available ones. They are extremely durable, very safe for packing food items and approved by FDA, and support high-speed packaging applications and have a great puncture and tear resistance. All thee makes Polyolefin shrink film the most preferred and premium wraps.
Main Characteristics of POF
-Value for Money
The durability and cost-effectiveness makes POE films most preferred film by many suppliers
POF mare also completely recyclable which makes them the most environment-friendly shrink films available.
-Faster Shrink Rates
POF makes the wraps shrink faster. It is great to pack food and consumer products. Because of its excellent clarity and polished shelf appearance, they are used to pack food and consumer retail products
Polyethylene Shrink (PE) Films
PE is a type of polyolefin shrink films but comes in several forms. It is used in protective packaging called shrink film and stretch film. They come in three forms – HDPE, LDPE, and LLDPE.
-High-Density Polyethylene (HDPE)
HDFE film is made of petroleum with a high ratio of strength and density. They are used in the manufacture of tough plastic products like bottles, plastic jars, milk jugs, and piping’s. Just like POF, because of durability, they are used in consumer products like beverage bottles, personal care, and retail products.
-Low-Density Polyethylene (LDPE)
This has a lower density and subsequently lower mass. They are highly recyclable too and hence are widely used in manufacturing bottles, lids and cables.
-Linear Low-Density Polyethylene (LLDPE)
LLDPE is stretch films making them very popular in the packaging industry. They offer more strength and excellent mean for stretching. Hence they are widely used for packing heavy loads, snacks, frozen foods. LLDPE also have more strength and durability compared to other PE films.
Now that we have seen different types of Shrink Films, we will see the advantages they offer as a whole to the packaging industry.
Shrink films offer a great deal of protection to the items in the package. Because of their high resistance to puncture and tear, shrink films minimize the damage to products during the transit. They can also work as odor barriers and hence increase the shelf life of products.
2. Better Visual Presentation
Because of their ability to control moisture movement into and out of the packages and anti-fog characteristics, shrink films can provide a better visual presentation of food packages. Polyolefin shrink film is also suitable for graphic prints and designs which will increase the visual appeal.
3. Recyclable and Environmentally Viable
One of the greatest benefits of shrink films, especially Polyolefin shrink film and PE is their ability to recycle. They also do not have a harmful environmental characteristic like PVC, which makes POF most desirable packaging solution
4. Cost Effective
The durability and strength of shrink films mean that packaging can be done with multiple products together which improve productivity and reduce cost. Heavy products also have a lot of protection including uses of shrink films, and hence to reduce exterior damage. This makes shrink films the most cost-effective package solutions.
To sum up, Shrink films, especially the Polyolefin shrink film and PE are very versatile and durable packaging options to pack and transport large quantities, both heavier and delicate, products with minimum damage and higher efficiency. While POF is clear winners considering their reliability, recyclability and the protection they offer, there are different types of shrink films based on a variety of requirements. However, it is important to take the environment and protection into consideration while doing so.