for producing a plastic film having a plastic fastener , with male and female interlockable profiles , and accessory strips , such as ribs and strips , in preparation of a reclosable plastic bag , there is provided a first forming die which extrudes the accessory strips , a separate second forming die which extrudes the fastener , a pair of nip rolls for press - bonding the accessory strips onto the surface of the film being fed in the vicinity of the first forming die , and a bonding roll for receiving the film with press - bonded accessory strips and the fastener from the second forming die placed onto the film surface such that the fastener is bonded to the surface of the film at the bonding roll by virtue of heat .