Back Sealed Bag Introduction

Back sealed bag, also known as center sealed bag, is an exclusive word in packaging industry. Simply, it is a kind of packaging bag with its back sealed. The back sealed bags have a wide range of application field, usually candies and fruits, instant noodles, milk packaged in bags, etc. can adopt this kind of packaging form.

Compared with other kinds of packaging forms, back sealed bag has no side seals which assured the integrity of the front picture on the package which is more beautiful. At the same time, the designer can finish the picture on the package as an integrity which ensures the coherence of the picture. On the other hand, because the seal is on the back, so the both side of the bag should take much more pressure which lowered possibility of the damage of the bag. More over, compared with the same size packaging bags, the back sealed bags has the shortest seal which lowered the broke up of the bag on the sealed side.

From the aspect of the material, there is no difference between back sealed bags and heat sealed bags. In addition, there are a lot of examples for the changing of package, such as aluminum-plastic and aluminum paper compound bags. The most common examples are the package of the milk and big packaged sunflower seeds.

The difficulty of the manufacture of the back sealed bags and the package is the heat T-seal. It is very difficult to control the temperature of the T-seal. If the temperature is too high, the other parts of the bag will be plicated due to the high temperature. If the temperature is too low, there will be too difficult to seal T-seal well.

There is one thing the designer should pay attention to when designing the picture on the package of the back sealed bags: the front picture should be larger than the size on the finished product in case the front picture is too small when the picture is on the package. At the same time, the designer should consider if there is need for the up and down, left and right to have a seal or if the set of the spot position conform to the need of the bag cutting. In addition, confirm if there is need to use transparent color or same color to connect is the other aspect the designer should pay attention to.