Open-top, square-bottom bags have better compressive strength than paper bags.

Open-top square-bottom bags are a new generation of woven-bag products that were gradually introduced from the United States in the 1990s. These bags serve as medium- and small-sized bulk-container packaging solutions; they are convenient to use, easy to clean, and feature a compact design, making them one of the most popular packaging materials worldwide and particularly well suited for export and import applications. Square-bottom valve bags offer superior sealing performance. In conventional packaging bags, the bottom and sealing seams are stitched using sewing-machine thread, which often punctures numerous holes on the left side of the woven fabric at the stitching points. Since the sewing thread does not securely grip these holes, leakage is prone to occur. To prevent such leakage in self-sealing bags, it is sometimes necessary to line the bag with a plastic inner liner, which not only increases costs but also reduces labor efficiency during filling operations. By contrast, square-bottom valve bags utilize adhesive to bond the double-layer woven fabric at the bottom, thereby eliminating the risk of leakage at the source. After filling, these bags can be immediately stacked without requiring additional sealing.

Open-top square-bottom bags offer superior compressive strength compared with paper bags, are reusable, and exhibit excellent water resistance. A key advantage of these bags is their recyclability; they can be cleaned with tap water, which is a common practice. However, this method wastes water, and detergents containing phosphorus can contaminate soil. Moreover, standard cleaning methods generally fail to eliminate pathogens.

Application areas for open-top square-bottom bags include chemical raw materials, inorganic pigments, food additives, pharmaceutical excipients, and architectural decorative materials. The open-top square-bottom bag is a branded packaging solution that seamlessly integrates traditional design principles with innovative concepts. Its square bottom delivers performance comparable to that of square-bottom, tear-open bags, while its flat opening allows it to be sealed using conventional seam-sealing techniques—just as with sewn-bottom, tear-open packaging. Additionally, a thin film can be laminated onto the bag’s surface to provide waterproof protection for products requiring moisture resistance.

Open-top square-bottom bags are more environmentally friendly. With the advancement of new energy technologies, relevant authorities are vigorously promoting green and sustainable practices, even as air pollution continues to worsen. To address the problem of white waste and make our lives healthier and more sustainable, environmentally conscious individuals have turned their attention to a new product: the open-top square-bottom bag—whose advantages are self-evident.

Open-top square-bottom bag: also known as a valve bag or a flat-bottom bag, is currently one of the most popular types of packaging bags worldwide. It is filled through a top or bottom valve using a dedicated filling machine, and after filling, it is formed into a perfect cube. Key features of the open-top square-bottom bag include: high efficiency in increasing packaging height, convenient transportation, exceptional structural strength, and a low rate of damage. Compared with conventional bags, it offers a range of unparalleled advantages in plastic film packaging applications for chemical granules and powders, as well as agricultural products such as tapioca starch and fertilizers. For example: 1) The square-bottom valve bag boasts an aesthetically pleasing design and superior print quality; 2) Its high compressive strength enables it to withstand severe impacts and rigorous handling during transport, thereby reducing losses caused by package rupture.