Pouch Machines

Flexible packaging has been around for a long time but is becoming ever more popular. Flexible packages reduce physical inventory. A warehouse full of bottles may be replaced by a single pallet of film rolls.

One popular form of flexible packaging is the 3 sided flexible pouch. These may be continuous or intermittent motion and can run as speeds from a few dozen to a few hundred pouches per minute.

This pouch begins as film on a roll. Any type of heat sealable film can be used. Film may be unprinted or continuous printed or it can pattern printed in register. Unprinted or continuous printed pouches are formed to length and slight variations between pouches will not matter. Registered film must be indexed to the registration mark to assure that the graphics are registered as they should be.

As the film comes off the unwind roll, a series of dancer rollers align and tension it. Proper tension is critical to a good pouch and good registration. On lighter rolls at lower speeds, the pouch machine will pull the film off the roll. On heavier rolls or higher speeds, a powered unwind may be required.

As the film exits the dancer rolls, it is folded in half by a “V” shaped plow. In the case of a standup pouch, a secondary plow forms it into a “W”. Zipper strips for easy opening and resealability may be inserted at this stage.

After folding, vertical sealing bars seal the trailing edge of one package and the leading edge of the next. As the film indexes, grippers grab the leading edge of the pouch and a knife makes a vertical cut between the two pouches to individuate them. In some cases, instead of cutting them apart they may be perforated or even uncut to form a continuous strip.

Shaped pouches are also possible. Instead of straight sealing and cutting jaws, contoured jaws are used. The excess film material is discarded.

The pouches move to a filling section where a pair of suction cups pull the film open to allow introduction of liquid or solid product using standard filling equipment. Depending the product, multiple filling stations may be used. A chicken noodle soup mix may contain soup powder and chicken chunks each filled individually. When filling, it is important not to get any product on the seal area as this can prevent proper sealing.

After filling, a pair of jaws seal the top of the pouch. In some cases a fitment, such as a dispensing screw cap, will be placed and the film will be sealed to and around the fitment.  The pouch is then discharged to the next step in the packaging process.

See also:  Form and Fill Machinery