In 2021, more parcels were sent within Germany than ever before - 4.51 billion. Very few recipients pay attention to the artistic packaging. What would packaging be without a closure? Today, the tuck-in closure is standard for many carton sizes, and not without reason: it is practical, inexpensive, can be used multiple times, and allows for good visual solutions. Time to take a closer look at this modest all-rounder!

What is a push-in fastener?

A push-on closure is a type of closure in which a protruding tab on the lid of a carton is inserted into a punched opening provided for this purpose. It can be one longer flap or two shorter ones.

The plug-in closure is held in place by an additional closure tab, which in turn is pushed from the carton into the lid. This design allows the carton to be opened and closed again and again. The carton can thus be used several times.

What are the advantages of a push-in fastener?

It is no wonder that the push-fit closure is used extensively today, as it offers many advantages:

• Quick and easy closing of the package.
• Inexpensive: Flaps and openings are already integrated when the cardboard is cut to size. Additional adhesive tape is not necessarily required.
• Multiple use: The box can be opened and closed as many times as you like, only the material itself sets limits.
• Visually appealing: The entire lid of the box and the side walls can be printed.

For which products are cartons with tuck-in closure suitable?

The plug-in closure can be used for boxes of different sizes. You can therefore find it on flat maxi letters, medium-sized shipping boxes or even oblong formats. Three examples from practice:

1. Maxi letter box: The dimensions of the maxi letter box are based on the Deutsche Post criteria optimized. This means: maximum height 5 cm, length up to 35.3 cm, Width up to 25 cm.
   
   The Maxibrief may weigh up to 1 kg and is priced at 2.75 euros. cheaper than a package. Sent as a maxi letter, there are no restrictions on the content - it can also be a gift of a book with a personal letter.
   
   An adhesive strip may not be necessary. However, you can use it if you want to make sure that everything arrives in one piece and will only be opened by the intended recipient.

   If you are shipping online, another function of the Maxibrief box is even more interesting and important for you.
   
   Boxes in this format can be sent even more cheaply as book and merchandise shipments: up to 500 g for 1.95 euros and up to 1 kg for 2.25 euros. Anything that is considered merchandise is permitted - from books to small electronic parts or textiles.
   
   However, at most an invoice or delivery bill may be enclosed, not a letter. With this form of shipping, Swiss Post reserves the right to open in order to check for misuse.
   
   The plug-in closure with sealing flap makes this easy. Online retailers who ship a lot can also use the format for merchandise mail. It also has fast transit times and special conditions for collection.
   
   However, a separate contract with Deutsche Post is required for this. Feel free to check if this option is advantageous for you!
   
   

2. Set-up carton with push-fit closure: You have an online shipping business and can't manage with the Maxibrief? Set-up boxes with push-fit closures come in a variety of sizes, from small boxes measuring 10 cm x 8 cm x 6 cm to large parcels measuring 43 cm x 30 cm x 18 cm.
   
   Most of them can be loaded with up to 30 kg - the maximum allowed by Deutsche Post. Whether dog food, winter jackets or spare car parts: The corrugated cardboard box reliably protects the goods so that they reach the recipient undamaged.
   
   The package can be easily closed with the plug-in closure. Don't forget to pad the carton if you want to transport sensitive goods in it.
   
   Another advantage is that when the set-up carton is not in use, it can be folded flat and does not take up much space.
   
   This means that it is no problem to always have a stock of different sizes of it and to be prepared for all situations. These boxes can be unfolded and filled very quickly. Optimal, therefore, when the customer needs to be served quickly.

3. Folding boxes with plug-in closure: Some folding boxes are the size of a maxi letter, while others can be used to pack entire poster rolls or plans, up to a size of 75 cm x 11 cm x 7 cm.

   Posters in folding boxes do not have to be shipped as bulky goods thanks to their rectangular, stack-friendly format, which saves postage.
   
   The double outer walls make folding boxes particularly stable and up to 30 kg may be shipped in them. However, they are also popular for smaller and lighter parts, such as electronics. In the well-padded folding box, such items reach their recipient without damage.
   
   

Cartons with plug-in closure are available in various sizes. Books, handy goods and even posters can be shipped in them.

Packaging and marketing

A carton is initially used as a container to transport goods safely to the customer. But why not use the space that the box has? Next to the addresses there is enough space for your logo or motto.

Thanks to the plug-in closure, you don't need any or not much tape - and the customer can immediately see which longed-for package has arrived. Most boxes are in a practical brown color. However, if you want to really show off your logo, you can also choose one in white.

Material cycle of corrugated board

Packaging cartons are usually made of corrugated board. Corrugated board is known to be made from the renewable raw material wood, mostly from thinning and broken wood. The cardboard can be completely recycled. New corrugated board already consists on average of about 80 percent waste paper.

Even the adhesive used to produce the corrugated board is now plant-based. Today, cardboard packaging can therefore always be returned to the material cycle. This protects the forest and saves energy.

• Reuse: Manufacturers and mail-order companies pack new merchandise in new cartons. However, if the goods are not returned as a return, they will not see these cartons again. Normally, however, the cartons are still in very good condition when they reach the recipient.

Therefore, it is optimal if recipients use them again, for example to store things or to send personal gifts. Direct reuse is the best possible utilization of the raw material. The fact that a cardboard box with a plug-in closure can be opened and closed again and again offers an advantage in this regard. In this way, the material is protected, which increases its service life.

• Recycling: One possible form of recycling in the commercial sector is when cardboard is shredded and used as filling material. If no direct new use can be found for the cardboard, it can be sent for recycling.

The tuck-in closure helps ensure that only a minimum of tape needs to be used to secure goods in transit - in some cases, none at all. Adhesive tape damages the carton, reducing its ability to be used multiple times. Adhesive tape also cannot be recycled and must be removed before recycling.

Packaging cartons made of corrugated board can be fully recycled. The eco-balance can be additionally improved if shipping cartons are used several times.

Alternatives to the push lock

In addition to the tuck-in closure, there are also other closure variants depending on the carton size and purpose. For example, the shape of the tuck-in flaps can vary, they can have side flaps or be notched for security. Some prefer a self-adhesive closure. But then the carton is not so easy to use again.

Another form of packaging are slip lid boxes, which are often used for gifts. For special formats such as bottle or tire cartons, there are individual solutions that require adhesive tape.

Conclusion

The cardboard box may have been around for more than 100 years, but there have never been as many of them in circulation as there are today. Online retailing has revolutionized our shopping behavior - and with it the packaging culture, which is always on the lookout for efficient, economical solutions. The push-fit closure is one that has really stood the test of time - functional, inexpensive and environmentally friendly all at the same time.

FAQ

1. What closure options are available for shipping cartons?
   Depending on the carton shape, there are various options, for example tuck-in flaps, self-adhesive closures or the tuck-in closure. For particularly large, heavy or breakable products, there are special designs with individual solutions.

2. Do I need additional adhesive tape for a plug-in closure?
   Not necessarily. If it is a well-packed, not too heavy goods, a minimum is enough if you want to be completely safe. It is not necessary to wrap the box with it several times! For a heavier item, however, a little more tape is recommended.

3. How often can you use a carton with a tuck-in closure?
   It is particularly environmentally friendly to use a carton multiple times. However, you should make sure that the intended recipient of the package is clearly visible and that old addresses do not cause confusion during delivery.
   
   We can't guarantee how long a box will last, because that depends on the contents and how it has been handled. However, feel free to use your stored shipping boxes to send Christmas and birthday gifts!