Patent ID: 7076930

Claim:
Process for the packaging of products with thermoplastic and stretchable film, comprising the steps of: tubularizing of a stretchable and thermoplastic film unwound from a feeding bobbin, with longitudinal welding of its longitudinal edges, in such a manner to form a continuous tube, arranged almost horizontally and having a transversal section with a width which is suitable for the introduction of the product to be packaged; sealing, with at least one transversal welding, of the head of said film which comes out from the tubularization and longitudinal welding phase and supporting of the said closed head, in such a manner that the same tube remains in a substantially horizontal position; introducing of the product, inside of the tubular wrapping portion formed around a forming tube, closed and anteriorly supported, in such a manner to result near to said anterior end of the tubular wrapping; transversally blocking of the wrapping film in a zone which does not touch the product; longitudinally stretching of a portion of the tubular wrapping posteriorly blocked, the whole in such a manner that said wrapping portion assumes a length which is superior to the length of the incorporated product, while the same wrapping, because of the reaction to the stretching, tightens transversally on the product and wraps it in a close manner; closing with at least a transversal welding, of the posterior end of the tubular packaging longitudinally stretched, further closing with at least another transversal welding of the head of the tubular wrapping which follows the formed packaging, transversal cutting of the tubular wrapping film in the zone lying between the two said weldings, while the head of the new tubular wrapping is retained, while the tail of the formed packaging is also retained too, while said packaging is horizontally supported and while in phase the head of the same packaging is abandoned, in such a manner that the film which composes the same can longitudinally react to close adhere also in this sense to the packaged product; supporting the transversally closed head which comes out of the tubularization and welding phase, in such a manner that the same tube remains in a substantially horizontal position; said transversal blocking comprising braking of the wrapping film by pressing the film against said forming tube in a zone which does not touch the product; interrupting the transversal braking action of the packaging film, in phase with the closure of the posterior end of the formed packaging; and abandon of the grip of the posterior end of the formed packaging and displacement of this latter from the packaging zone.