Canning and Fish Packaging Technology

Unit 11 - Heat Sealing

11.1.1.2.Hot wire sealing
This gives a bead seal. A hot wire contacts the two films placed between it and the opposing unheated surface. The wire is raised to red hot temperature electrically which seals and cuts the film at the same time.

This method can be used on homogeneous thermoplastic materials which can tolerate high temperatures for atleast a short time and which have a low viscosity in the fused state. This method is mainly used for the manufacture of bags and pouches from polyethylene film in tubular form. This method is particularly suitable for cutting PVC cling films or shrink wrap film.