9. Vacuum sealing

For production rates lower than those of thermoformers, e.g. for semi-industrial installations such as butcheries or wholesale delicatessens, there are vacuum or protective gas sealers, which work from 2 to 8 cycles/min, with rigid trays.

Tool movement is automatic; sealing plates can be equipped with either cold zones for atmosphere packaging, or heated zones for skin-type packaging. Trays are ejected automatically at the end of the cycle. The lower tool pulls the film.

The film is fed by grippers, independently of the tooling movement. The film feed pitch is adjustable according to a time delay set by a printed spot detected by fiber optics. The operator can change format in just a few minutes.