How Are Brown Paper Bags Made?

Bag Styles and Materials

There are several main paper bag styles, including serrated top, folded top, die cut, macramé and knotless macramé. The serrated top bag is the most common and the most economical; some come with paper twist and plastic tube handles. There are two types of folded-top bags, ultra modular and JV slit. The die-cut bag has a serrated or folded top. The knotted and knotless macramé bags come in four styles: 1 ½-inch top fold, soft-handled with an inside patch, the slit top and the ultra, which has a value-added smooth finish. Paper bags come in several different paper grades, including natural brown and bleached white Kraft, oatmeal, flipside, beater-dyed, white claycoat and synthetic. They also come in coated and uncoated textures. Weights vary from 60# to 184# for the synthetic bags, which do not crack and yield superior holding strength. Some companies order paper bags with print and artwork, which is done in various colors, inks and print styles. Based upon wood, a natural renewable resource, paper is biodegradable and recyclable and a source of energy after use. The pulp and paper industry is well fitted to meet the challenge of sustainable development, from the forest through the production of pulp and paper and finally through recycling.

Methods

The present invention of paper bags, such as shopping bags, are manufactured with angulated bottoms and handles by continuously moving a material paper forward in a rotary-type manufacturing machine. Two types of machines are used for manufacturing shopping bags with handles. One is a rotary-type machine that feeds material paper wound in a roll. The other is a sheet-fed type that feeds material paper cut to a predetermined size. The process flow of a bag includes a material paper feeding process, a cuts making process, a pasting process, a reinforcing pasting process, a material cutting process, and a top edge portion pasting and folding process, respectively.

The Basic How

Material paper is wound in a roll and continuously fed by the paper feeding unit to the cutting device. A rotary roller and pinch roller are rotated in mutually reverse directions to abut the cutting blade. Lateral slits and letter J-shaped nicks are formed in positions corresponding to the tapes of the handles. It is then conveyed to a handle pasting device by the paper feeding unit. The pasted handles are fed to the cutting device and conveyed to the folding device, which folds in the top edge with a drum. The front and back flaps of the bag are folded toward the inside and pasted together. The bottom is folded by the press rollers and pressed to form an angulated bottom. Finally, strings may be laced through the bores and tied to the paperboard.

Resources

• Earth 911
• Make your own gift bags