A laser welding system is directed to simultaneously joining respective layers of a first bag and a second bag. The system includes a first film layer adjacent to a second film layer for forming the first bag, and a third film layer adjacent to a fourth film layer for forming the second bag, each layer of the plurality of film layers being made of a thermoplastic material that absorbs laser radiation having a wavelength of about 2 microns. A non-absorbing carrier film layer is positioned between the second film layer and the third film layer, the non-absorbing carrier film layer being made of a material that transmits substantially all energy of the laser radiation. A laser source applies the laser radiation toward portions of the plurality of film layers to be joined, forming the first bag generally simultaneously with the second bag.