| 摘要 |
An air-evacuable bag has a one-way valve therein having two layers of valve film (38,42), neither of which is the sidewall layer (40,44) of the bag. A method for the manufacture of such air-evacuable bags incorporates a roll (20) supplying a first valve film layer (38), a roll (30) supplying a first sidewall layer (40), a roll (22) supplying a second valve film layer (42), and a roll (32) supplying a second sidewall layer (44). As the film (38) coming off the first valve film layer roll (20) passes the roll (30) supplying the first sidewall layer (40), both the first sidewall layer (40) and first valve film layer (38) move in close proximity to one another until the first valve film layer (38) is tacked to the first sidewall layer (40). The second valve film layer (42) and second sidewall layer (44) are processed simultaneously in a like manner, and all four layers (38,40,42,44) are joined at a sealing station. <IMAGE> |
