Four-Side Seal Pouches

Pouches can be made in a variety of styles. However, the majority can be categorized into one of four groups pillow pouches, three-side seal pouches, four-side seal pouches, and stand-up pouches. 

Flexible packaging such as laminates, films, pouches and sachets relies on various styles of seal. These may be fin (inside to inside) from a single web, overlap (inside to outside) from a single web, inside to inside from two separate webs (four sided seal), or one web folded over by a centre fold (three or four sided seal). 

Three-side seai pouches (Fig. 9.2(a)) contain two side seams and a top (or bottom) seam. The remaining side contains a fold. All seals are made between inner layers of the pouch material. If the pouch design incorporates gussets, these pouches can be capable of standing erect. In some applications, three-side seal pouches are used, but the side with the fold is also sealed, thus blurring the lines between three- and four-side seal pouches. 

Figure 9.2 Pouches, (a) three-side seal, (b) four-side seal (reprinted with permission from [2])...

Four-side seal pouches (Fig. 9.2(b)) are made from two webs of material, which are sealed together at the top, bottom, and both sides of the pouch. Unlike the pouches previously discussed, the front and back sides of the four-side-seal pouch can be made from different materials. A variation on this idea is production of pouches in nonrectangular shapes. These pouches may have a variety of decorative shapes. 

Find examples of three-side seal and four-side seal pouches. Describe each one. 

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