You may not realize it, but you see four-seal bags all the time, especially if you buy your coffee at retail a lot.
This popular professional packaging format is designed to be used independently without assistance and offers a clean, modular look. With four panels that can display graphics and information, it’s a marketing department’s dream. Consumers also love the box bag for its easy storage and convenience.
1. Fabrication of four-seal bags
Four side seal bags get their name from the 2 vertical panels and 2 gussets that are joined together by four vertical seals. They also have rectangular or square bottoms so they can stand on their own.
Square bags can be purchased pre-formed from a film supplier for further processing on a bag packaging machine, or can be made in-house at your business using a vertical form fill seal machine. Here is an overview of the differences between the two:
1) Packing in prefabricated four-seal bag
Going the pre-made route means you load pre-formed quad seal pouches into a pouch packing machine, which fills your product and then seals it. Pre-made four-seal bags have a premium appearance and are easy to process on packaging machines, but can be costly if produced on a large scale.
2) Create quadrilateral bags on a VFFS machine
To keep costs down, many large businesses choose to create, fill and seal quadrilateral bags on vertical form fill seal (VFFS) machines. It works like this:
A long, wide roll of flat packaging film, called a web, is loaded into a VFFS machine. The roll of film is pulled through the equipment and guided over a rectangular forming tube, forming a quadrilateral bag shape. Four vertical seals give it its structured shape, the block bottom assembly forms the bottom of the bag, and the horizontal seal forms its bottom seal. After the bottom seal is created, your product will be filled into the quad bag and the package will be given a final horizontal top seal to close it.
Using a VFFS machine to make quad-seal bags is a popular choice and has unique advantages: Each bag costs less than buying pre-made bags and can often be made on a VFFS machine at higher speeds. However, being your own bag making machine comes with its own challenges: not the least of which is that operators require higher technical skills to operate the equipment and there is more room for error.
2. Advantages and limitations of four-side seal bags
This packaging format has many advantages that are attractive to CPG companies, contract packers and consumers. Four-side sealed bag:
- Stand upright without assistance. Unlike standard pillow bags, the quad seal bag is constructed to stand on its own, giving it a strong shelf presence.
- Great for heavier fills. With four vertical seals, quad seal bags are reinforced and strong, making them ideal for bulk products.
- is a sustainable choice. Since the gussets of the four-seal bag unfold in an accordion-like fashion, this pack type has a low pack-to-product ratio, which is a good idea for those who need to adjust the pack size to its contents to reduce waste. choose.
- Provide more space for branding or information. Both the vertical panels and the side gussets can be printed with messages, information and branding, making the quad bag a great marketing piece.
Despite all the positives, like any other form of packaging, quad seal pouches have their drawbacks. This package type:
- The cost is higher than some others. Four-seal bags do cost more to produce than less complicated bag styles like pillow bags. As a result, machinery that automatically packs products into quad-seal bags also costs more.
- Requires more technical expertise to create. When you choose to manufacture quad seal bags in-house on a VFFS machine, a machine operator with more technical expertise will be required. Since these machines have more components and moving parts, there is more room for error.
- May become unstable after emptying. The bottom of the 4-side seal bag is folded over, not flat. So when the pack is full, it’s heavy enough to flatten the bottom of the bag to stand up effectively. But when the pack is emptied, it loses weight, which means the seal may not be as flat, causing the quad bag to tip over.
- Can be laid flat for heavier fillings. Sometimes, when producing larger, heavier quad seal pouches, the weight distribution and design of the bag means it has to lay flat to remain stable. This will limit the visible panels for marketing and will take up more space on the shelf.
3. Packaging application trends of four-seal bags
Four-seal coffee bags have been the packaging of choice for most coffees in modern history, often with a one-way valve to preserve freshness.
Sometimes going through the extra process of folding and taping the top of the bag, this iconic bag type is considered the face of the packaging world and likely will be for many years to come.
1) Pet food packaging
Due to their durability and strength, four-seal bags are commonly used in pet food packaging (especially bulk packaging). For heavier fills, handles are often added to the top of the quad bag.
Many modern pet food companies are adding a matte finish to their square bags, creating a more premium look and feel for those looking for specialty products for their pets.
2) Sweets and Treats
Often featuring resealable options such as zippers and clear panels for viewing the contents of the package, four-seal bags for snacks and candy are a popular option. While quad seal pouches are used in these industries, these products will appeal to those looking for a premium, low-volume look.