Process and apparatus for assembling two films, in particular films of a few microns thickness

Apparatus for joining two films (1, 2) and of the type comprising an assembly table (5) to spread out the films, film-supply means (9), means (24, 25, 27) supplying reinforcing bands (3, 4) and a movable unit (6, 7) which is longitudinally displaceable above the assembly table (5) and holding on one hand positioning means (10, 11, 26, 33, 34) designed to align the edges to be joined of the films (1, 2) and the reinforcing band (3, 4) and on the other hand heatsealing means (14, 15, 16, 17) for said films and reinforcing band, said apparatus comprising:

• the supply means (24, 25, 27) of reinforcing band (3, 4) comprising means (24, 25) supplying a junction tape (3) and means (27) supplying a plane, so-called positioning tape, the heat-sealing means (14, 15, 16, 17) are designed to:
• seal the junction tape (3) on the longitudinal edge of a so-called first film (1), seal the positioning tape (4) or the longitudinal edge of a so-called second film (2) to that side of the junction tape (3) which is opposite the first film (1), the positioning means (10, 11, 26, 33, 34) comprise:
• guide means (10, 11, 26) designed to position within the same alignment a longitudinal edge of the first film (1), the junction tape (3) and the positioning tape (4), positioning means (33, 34) for the positioning tape (4) which are designed to position within the same alignment the longitudinal edge of the first film (1) hemmed by the junction tape (3) and the positioning tape (4) on one hand and on the other an edge to be joined of the second film (2), means (31, 35, 36, 37) for separating the positioning tape (4) from the junction tape (3) are mounted on the movable unit (6, 7) in order to separate said junction tape (3) from the said positioning tape (4) in such a manner as make possible the joining of the edges of two films (1, 2) aligned by the positioning means (33, 34) of the positioning tape (4).