Process for Producing Ultrasonic Seal, and Film Structures and Flexible Containers with Same

Abstract

The multilayer films are arranged such that the seal layer of the first multilayer film is in contact with the seal layer of the second multilayer film. The seal layers form an ultrasonic seal having a seal strength from 30 N/15 mm to 80 N/15 mm when ultrasonically sealed at 4 N/mm seal force.

1 - 15 . (canceled) 
     
     
         16 . A flexible container comprising:
 a multilayer film having a backing layer and a seal layer, the multilayer film folded upon itself to form a first film portion and a second film portion such that opposing seal layers contact each other;   each seal layer comprising an ultrasonic sealable olefin-based polymer (USOP) having the following properties:
 (a) a heat of melting, ΔHm, less than 130 J/g, 
 (b) a peak melting temperature, Tm, less than 125° C., 
 (c) a storage modulus in shear (G′) from 50 MPa to 500 MPa, and 
 (d) a loss modulus in shear (G″) greater than 10 MPa; 
 the multilayer films arranged such that the seal layer of the first multilayer film is in contact with the seal layer of the second multilayer film; and 
   the seal layers form an ultrasonic seal having a seal strength from 30 N/15 mm to 80 N/15 mm.   
     
     
         17 . The flexible container of  claim 16  wherein the second film portion is superimposed on the first film portion to form a common peripheral edge;
 a 2-fold zone and a 4-fold zone; and 
 the 2-fold zone and the 4-fold zone each forming an ultrasonic seal having a seal strength from 30 N/15 mm to 80 N/15 mm. 
 
     
     
         18 . The flexible container of  claim 17  wherein the 2-fold zone comprises at least a portion of the common peripheral edge. 
     
     
         19 . The flexible container of  claim 17  wherein the 4-fold zone comprises at least a portion of a longitudinal seal. 
     
     
         20 . The flexible container of  claim 16  wherein the backing layer is a material selected from the group consisting of PET, polyamide, BOPP, and metal foil. 
     
     
         21 . The flexible container of  claim 16  wherein the USOP is a material selected from the group consisting of PBPE, LLDPE, ULDPE, POP, and combinations thereof. 
     
     
         22 . The flexible container of  claim 16  wherein the backing layer comprises BOPP and the seal layer is a monolayer comprising a USOP selected from the group consisting of a ULDPE, a POP and a PBPE and the seal layers form an ultrasonic seal having a seal strength from 55 N/15 mm to 80 N/15 mm. 
     
     
         23 . The flexible container of  claim 16  wherein the backing layer is PET and the seal layer is a monolayer comprising a USOP selected from the group consisting of a ULDPE, a POP, and a PBPE and the seal layers form an ultrasonic seal having a seal strength from 37 N/15 mm to 55 N/15 mm. 
     
     
         24 . The flexible container of  claim 16  wherein the seal layer is a coextruded structure comprising a face layer, a core layer, and an inner layer;
 the face layer comprises a USOP selected from the group consisting of a ULDPE, a POP, and a PBPE; and 
 the seal layers form an ultrasonic seal having a seal strength from 35 N/15 mm to 55 N/15 mm. 
 
     
     
         25 . The flexible container of  claim 16  wherein the seal layer is a coextruded structure comprising a face layer, a core layer, and an inner layer;
 at least one of the core layer and the inner layer comprises a USOP selected from the group consisting of a ULDPE, a POP, and a PBPE; 
 the face layer is void of a USOP; and 
 the seal layers form an ultrasonic seal having a seal strength from 35 N/15 mm to 50 N/15 mm.