What are the characteristics of back sealed bags, three sided sealed bags, and four sided sealed bags? What are the differences in packaged food?

When it comes to plastic packaging bags, various packaging images come to mind. Although we see these everyday items every day, few people know which type they belong to. In fact, the three most common types of packaging bags in daily life are back sealed bags, three sided sealed bags, and four sided sealed bags. The following are three common types of sealing bags and their respective application characteristics.
1. Three sided sealed bag
The common snack food, rice, tea, facial mask, etc. in supermarkets are usually packed with three side sealing bags. In terms of bag type, three side sealing bags are the simplest and most common. Its style is three sided sealed and one side open, leaving only one opening for users to install products. Its advantages are: good airtightness, excellent moisturizing and sealing performance; High degree of barrier, extremely low degree of oxygen and moisture permeability; Strong ability to prevent moisture and mold growth; The appearance is bright and beautiful, and it is non-toxic and odorless; After forming the bag, it can be unfolded into a three-dimensional bag shape, with high space utilization efficiency;
In addition to the points mentioned above, the three sided sealing bag has strong expandability and can be customized according to needs. The resealable zipper, easy to tear opening, and hanging holes for shelf display can all be achieved on the three sided sealing bag.
2. Back sealed bag
A back sealed bag, also known as a pillow shaped bag or a middle sealed bag, is composed of three seams at the top, bottom, and back to form a pillow shape. The back sealed bag adopts a hidden longitudinal edge to ensure the integrity of the front pattern of the packaging to the greatest extent. In the packaging design process, the bag body pattern is set as a whole to maintain the continuity of the picture, exquisite and beautiful, and distinctive appearance characteristics. The sealing of the back sealed bag is on the back, which enhances the pressure bearing capacity on both sides of the bag and greatly reduces the possibility of packaging damage. Packaging bags of the same size sealed with a back seal have the smallest total length, which to some extent reduces the probability of the seal cracking. Finally, the back sealed bag can effectively reduce the cost of packaging materials, with less consumables used. It can reduce the amount of packaging materials by about 40% without affecting production speed, and has a significant cost advantage.
And its inherent advantages such as moisture-proof, waterproof, insect proof, and anti scattering make the back sealing bag widely used, mainly for product packaging, storing drugs, cosmetics, food, frozen food, etc.
3. Four sided sealed bag
Four sided sealing of the bag means that all four edges are packaged in the form of heat sealed bags. Usually, a whole packaging film is divided into two halves for relative packaging, and the overall heat sealing and single bag cutting method is used. During production, controlling the alignment of one side can achieve good packaging effect. So both in terms of packaging materials and production equipment, they have high adaptability and stability. After packaging the product in a four sided sealed bag, it appears as a cube with good packaging effect. It can be used for food preservation and is suitable for multiple recycling; By utilizing a new printing process, the packaging patterns and trademarks can be more prominently displayed, resulting in a visually striking effect. Four sided sealed bags are resistant to steaming, moisture, and have excellent vacuum pumping effects. In addition to the characteristics that other packaging bags may also possess, their strong antioxidant and anti-static properties can better protect products from damage caused by external environmental factors and efficiently extend shelf life.