How to Avoid Bag Breakage in Spout Pouch Production

Bag breakage in spout pouch production happens mostly at two stages: bag making and spout insertion, so control has to be applied point by point along the process.

In making the stand-up bag itself, pay particular attention to punching, bottom gusset forming and bottom heat sealing. The joint where the four layers meet the two layers is especially prone to breakage; the transverse sealing bar alone is not enough there, so an additional heat-sealing bar is fitted, and some products require reinforced sealing as well, so that the joint holds as it should.

A stand-up pouch with a spout also needs good opening performance, otherwise the suction cups cannot pull the mouth open for spout insertion. The friction coefficient of the bag surface has to be low, and surface static must be removed during bag making so that bags do not cling to one another, which would hamper the spout-sealing machine when it picks up a bag.

At present, spouts are fitted to stand-up pouches in China mainly by two methods: manual insertion and heat-seal insertion. The heat-seal method transfers temperature to the spout by conduction, melting the spout so that it welds to the PE sealing layer of the bag and forms a firm joint.

With their strong shelf presence, stand-up spout pouches are favoured across many industries, and in the daily-chemical field in particular more and more products are packed in them. Liquid soap and shampoo in stand-up spout pouches are now common on the market: the printing is fine, transport and carrying are convenient, and they are gradually replacing conventional plastic and glass bottles.

Liquid stand-up spout pouches serve not only as juice pouches, soymilk pouches, jelly pouches and sweet bean sauce pouches, but are also widely used for laundry detergent pouches, fabric softener pouches and other daily-chemical packaging, where the very same pouch format serves a very different kind of product.