Vertical form fill seal (VFFS) packaging machines are used in almost every industry today, for good reason: They are fast, economical packaging solutions that conserve valuable plant floor space.
Bag Forming
From here, the film enters a forming tube assembly. As it crests the shoulder (collar) on the forming tube, it is folded around the tube so that the end result is a length of film with the two outer edges of the film overlapping each other. This is the beginning of the bag forming process.
The forming tube can be set up to make a lap seal or fin seal. A lap seal overlaps the two outer edges of the film to create a flat seal, while a fin seal marries the insides of the two outer edge of film to create a seal that sticks out, like a fin. A lap seal is generally considered more aesthetically pleasing and uses less material than a fin seal.
A rotary encoder is placed near the shoulder (collar) of the forming tube. The moving film in contact with the encoder wheel drives it. A pulse is generated for every length of movement, and this is transferred to the PLC (programmable logic controller). The bag length setting is set on the HMI (human machine interface) screen as a number and once this setting is reached the film transport stops (On intermittent motion machines only. Continuous motion machines do not stop.)
Post time: Jul-27-2021