초록 ▼

A sandwich of plural films of thermoplastic orientable polymers wherein the adjacent surfaces of each adjacent film pair are in direct face-to-face contact while being positively advanced is positively deflected into a temporarily generally uiniform zig-zag or pleated configuration, the deflecting f

A sandwich of plural films of thermoplastic orientable polymers wherein the adjacent surfaces of each adjacent film pair are in direct face-to-face contact while being positively advanced is positively deflected into a temporarily generally uiniform zig-zag or pleated configuration, the deflecting forces being sufficiently strong that the films in the sandwich are cold welded together while being laterally stretched. The deflection into the temporarily pleated configuration can be repeated.

대표청구항 ▼

A method of simultaneously laterally stretching and laminating together at least two separate films formed from at least one thermoplastic, orientable polymer which comprises the steps of positively advancing said separate films under tension in generally spread out condition with the adjacent surfa

A method of simultaneously laterally stretching and laminating together at least two separate films formed from at least one thermoplastic, orientable polymer which comprises the steps of positively advancing said separate films under tension in generally spread out condition with the adjacent surfaces of each adjacent pair of said films in direct face-to-face contact to form a sandwich of separate films; and while maintaining said films in said tensioned sandwich condition and at a temperature substantially below their melting point, applying mechanical pressure to the opposite sides of the advancing film sandwich alternately in directions perpendicular to the opposite sandwich faces along a multiplicity of generally uniformly closely spaced loci extending parallel to the direction of advance to positively deflect said sandwich into a temporary generally uniform laterally zig-zag or pleated configuration to said sandwich, the magnitude of said mechanical pressure and the deflection produced thereby being sufficient to mechanically work the mutually contacting surfaces of adjacent pairs of films in said sandwich along said loci and thereby impart a permanent lateral stretch while coincidentally effecting cold-weld bonding together of the mutually contacting film surfaces. Apparatus for simultaneously laterally stretching and laminating together films of thermoplastic orientable polymer which comprises means for positively advancing under tension at least two separate films of said polymer in generally flat spread out condition with the adjacent surfaces of each adjacent pair of said films in direct face-to-face contact to form a sandwich of at least one pair of said separate films, and means for applying mechanical pressure to opposite sides of said advancing sandwich in alternating directions perpendicularly out of the faces thereof along generally uniformly closely spaced loci extending parallel to the direction of advancing to positively deflect the advancing sandwich and impart a temporary generally uniform zig-zag or pleated configuration thereto, the magnitude of such deflection being sufficient to mechanically work the mutually contacting surfaces of each adjacent pair of films along said loci and thereby impart a permanent lateral stretch while coincidentally effecting cold-weld bonding together of the mutually contacting film surfaces.