초록 ▼

Molten thermoplastic, such as polyethylene, and a hot melt adhesive are coextruded through a channel shaped profile die. While still molten, the channel shaped strip, having adhesive between the ribs thereof, is brought into contact with a moving web of a thermoplastic, e.g. polyethylene film, which

Molten thermoplastic, such as polyethylene, and a hot melt adhesive are coextruded through a channel shaped profile die. While still molten, the channel shaped strip, having adhesive between the ribs thereof, is brought into contact with a moving web of a thermoplastic, e.g. polyethylene film, which is backed up by a roll at a controlled temperature. The temperature differential between the roll and the molten thermoplastic is maintained so that the thermoplastic adheres to the moving web upon contact and thereafter cools to set the thermoplastic in the channel shaped profile. The web is under tension so that contraction of the film upon release compensates for the contraction of the channel shaped strip as it cools.

대표청구항 ▼

A method of attaching a channel shaped adhesive strip having ribs along each side and an adhesive layer between said ribs to a plastic film comprising: moving a web of said film past a coextruding assembly; extruding a channel shaped strip of thermoplastic onto said moving web; applying a layer of a

A method of attaching a channel shaped adhesive strip having ribs along each side and an adhesive layer between said ribs to a plastic film comprising: moving a web of said film past a coextruding assembly; extruding a channel shaped strip of thermoplastic onto said moving web; applying a layer of adhesive between the ribs of said strip; and maintaining a temperature differential between said molten thermoplastic and said moving web so that said extruded thermoplastic channel strip adheres to said moving web upon contact and thereafter cools to set said extruded thermoplastic channel strip in said channel profile with said adhesive between the ribs of said strip.