Plastic container with rupturable seal

Abstract

A rupturable seal includes a first and second thermoplastic polymer layer and a third continuous polymer layer between the first and second polymer layers. The third polymer layer forms a first physical polymer blend with the first layer, and forms a second physical polymer blend with the second layer. The third layer can include a continuous fibrous strip of nonwoven polymeric microfibers, which may melt within a sealing region. Methods of making such seals and multi-compartment containers comprising such seals are disclosed. Applications for food storage and preparation and other diverse end uses are disclosed.

1 . A rupturable seal, comprising: 
 a first and second thermoplastic polymer layer; and    a third continuous polymer layer disposed between the first and second polymer layers wherein the third continuous polymer layer is devoid of through openings and comprises a fibrous strip comprising nonwoven microfibers;    wherein the first and third polymer layers form a first physical polymer blend;    wherein the second and third polymer layers form a second physical polymer blend; and    wherein said blends are formed by thermoplastic material melting and flowing into the interstices of the microfiber strip.    
   
   
       2 . (canceled)  
   
   
       3 . The seal of  claim 1 , wherein the first and second physical polymer blends define a sealing region of the rupturable seal, and wherein the third continuous polymer layer comprises a distal portion spaced away from the sealing region.  
   
   
       4 . A container comprising the seal of  claim 1 .  
   
   
       5 . A container according to  claim 3 , further comprising: 
 a first thermoplastic sheet sealed to a second member along at least one permanent seal and at least one rupturable seal that defines a first compartment within the container; and    wherein the rupturable seal is disposed between the first sheet and the second member to form the rupturable seal.    
   
   
       6 . The container of  claim 5 , wherein the second member comprises a second thermoplastic sheet.  
   
   
       7 . The container of  claim 5 , wherein the first thermoplastic sheet comprises an inner thermoplastic layer and an outer strengthening layer.  
   
   
       8 . The container of  claim 5 , wherein the container comprises a second compartment and wherein the rupturable seal separates the first and second compartment.  
   
   
       9 . A container according to  claim 4 , wherein the container holds a food product.  
   
   
       10 . A food storage article comprising the container of  claim 8 , and further comprising a first food compartment sealed in the first compartment and a second food component sealed in the second compartment.  
   
   
       11 . The food storage article of  claim 10 , wherein one of the first and second compartments comprises an expandable portion.  
   
   
       12 . A method of preparing food, comprising: 
 providing the food storage article of  claim 10;  and    heating the food storage article to an extent that vapor pressure in at least one of the first and second compartments causes the rupturable seal to break.    
   
   
       13 . The method of  claim 12 , wherein the pouch further comprises edge seals around the periphery thereof that do not break when the rupturable seal breaks.  
   
   
       14 . A method of making a rupturable seal, comprising: 
 providing first and second transparent thermoplastic sheets;    positioning a continuous fibrous strip comprising nonwoven micro-fibers between the first and second sheets to form a multilayer construction; and    applying sufficient heat and pressure to the multilayer construction in a sealing region to form a rupturable seal that is devoid of through openings.    
   
   
       15 . The method of  claim 14 , wherein the applying step yields a rupturable seal that is transparent.  
   
   
       16 . The method of  claim 14 , wherein the fibrous strip is oversized relative to the sealing region.