Patent ID: 8454872

Claim:
A method of injection molding an opening device on sheet packaging material for packaging pourable food products; said packaging material comprising at least a first layer of fibrous material and a second layer, and having an opening formed through said first layer of fibrous material and sealed by a cover portion of said second layer; and said method comprising: injecting molten plastic material onto a first side of said cover portion of said second layer that seals the opening in the first layer of fibrous material; feeding said molten plastic material along said cover portion to cover said cover portion on said first side; and feeding said molten plastic material through an annular peripheral portion of said cover portion to form a spout of said opening device projecting from a second side, opposite said first side, of said cover portion; said molten plastic material covering said cover portion defining, with the cover portion, a user-removable sealing portion of said spout.