In the wide world of flexible packaging, shrink film is perhaps one of the most common materials found on packaging lines throughout the globe. And while there are many different types of shrink film available, perforated films are one of the more curious forms of this soft plastic substrate.
Here at Industrial Packaging, we have been selling perforated shrink films for generations. One of the questions that we’ve been asked is: what exactly is the purpose of perforated shrink film? In addition to the prevention of ballooning, there are various benefits to perforated shrink film for specific applications. Today, we will take look at perforated shrink films and what they have to offer the modern packaging line.
What Is Perforated Shrink Film?
Perforated polyolefin shrink film is commonly used for packaging food and other items that emit a scent. Unlike regular shrink film, perforated shrink film has small holes punctured throughout the film. The holes are no bigger than a pinhead and are almost impossible to see with the naked eye.
There are a variety of ways that perforations are created. Some are hot needle perforations while others are now laser etched into the film. Traditionally, standard needle perforation is still the most common way to perforate film. This involves running the film over a roller with spikes on it which punctures small holes in specific patterns on the film.
Perforated films are often used to package hot bread and the air holes allow for crust bread. Sometimes called crusty bread film. It is up to you if you want to make changes. The blog is about perforated film, not necessarily how it is made.
Perforated film allows for the scent of the product to be experienced by the consumer. Once perforated shrink film has been shrunk inside a heat tunnel, the holes are not visible.
The holes in perforated shrink film are usually 2 - 2.5 centimeters apart and run throughout the entirety of the roll of film. The holes are useful for packaging products such as soap, potpourri, scented candles, food and other products emitting a scent that can impact the experience for the buyer.
Perforated shrink film is an excellent choice for packaging applications in which the products being packaged can benefit from being seen, handled and smelled by the consumer. Perforated films are commonly used with L sealers.
Certain OEMs produce film which is per-perforated prior to delivery to their clients. In this case, during a special operation unique to per-perforated film, the film is removed from the roll and is then run across rollers with needles protruding from the surface of the rollers. The precisely spaced needles imprint a pattern made of small holes across the entirety of the film. The perforated film is then wound back onto the roll.
End users who are utilizing equipment that has an old perforating system or lack thereof will find per-perforated film to be a welcomed solution for their packaging needs.
When it comes to figuring out the perfect number of perforations and the appropriate pattern of holes to imprint, experimenting is key. The process will likely involve making tweaks and adjustments until the best combination of perforations is discovered.
In this respect, a fair bit of trial and error should be expected however, reaching out to your local packaging expert may give you the opportunity to expedite the process via their advice and recommendations.
Need Help Choosing The Right Shrink Film?
Perforated shrink film has various benefits including:
- Scent Friendly Packaging
The tiny holes present in perforated shrink film allow for the scent of foods and other items that emit a smell to reach the noses of consumers. The perforations allow for the scent to escape the packaging much better than that of regular shrink film. This produces a level of interactivity and engagement with potential buyers who will often pick up the product, inspect it and smell it. Additionally, on top of interactivity and engagement, it's necessary for some products that sell themselves based on scent.
- Prevents Ballooning
Shrink film ballooning is a common problem that occurs when the shrink film comes in contact with hot air after the sealing process. Air becomes captured inside the shrink film causing it to appear as a balloon. Perforated shrink film negates ballooning as the air escapes from the holes as the film shrinks to fit the shape of the product while moving through the heat tunnel.
- High Clarity
Perforated shrink film has phenomenal clarity and is a great material to use when packaging items that have a visual appeal to consumers.
- Safe For Packaging Food
Not all shrink films are safe for packaging food however, perforated polyolefin shrink film is approved as food-safe by the FDA.
Potential Drawbacks Of Perforated Shrink Film
Perforated shrink film has a lot to offer certain packaging lines and applications, but it is not a good fit for all applications. Perforated shrink film comes in a limited array of sizes and may not work for certain sized products. Depending on the number of perforations in your film, running perforated shrink film may also produce wrinkled or sagging film. These symptoms can be negated by using a film with fewer perforations.
Dog ears (or unwanted flaps of film on seal corners) are another potential symptom of running perforated shrink film. In order to lessen the manifestation of “dog ears," it is advised to boost air evacuation by using perforated films with strategically placed perforations.
Reducing your bag size will help to eliminate dog ears. When running perforated shrink film and attempting to combat dog ears, slow down your conveyor speed and increase the air velocity and temperature of your heat tunnel. Finally, refocusing the shrink tunnel’s air flow onto the ends of the package will also help to reduce dog ears.
Is Perforated Shrink Film Right For You?
Depending upon the size and type of product you are packaging, perforated shrink film may or may not be a good fit for your particular applications. If you are packaging food and other items that emit a pleasant sent, perforated shrink film may be a good choice for packaging your products.
If your product should not be exposed to air or requires an airtight seal, perforated shrink film is not a good choice for your needs. In lieu of perforated shrink film, clear or printed shrink film would be a better fit in this instance.
When choosing a type of shrink film for your products, it is highly suggested that you reach out to a local packaging expert. Request an analysis of your current packaging processes and materials as well as the products you are planning to run. This will allow you to get quality advice and information about which size, width, gauge and type of shrink film will work best for your applications.
Depending on what type of film you are currently running, there may be some simple optimizations available to you. Implementing these optimizations could improve your current process, machinery, and materials and may result in significant cost savings without any upfront investment. For a free analyses of your current operation, please consider contacting one of our packaging professionals.
