Container package having improved seal

Abstract

A retortable container package includes a container and a composite closure. The container includes a 60 to 140 taper formed on an inboard side of the finish portion. A raised channel of the closure's insert disk includes a substantially flat top portion and an inner wall sloped at approximately the same angle as the taper angle. A sealant in the channel is deformed upon application of the closure onto the container such that the sealant forms a seal between the closure and each of (i) an outer wall of the finish portion proximate the lip, (ii) the lip, and (iii) the taper. Upon retorting, the seal between the container's taper and the channel inner wall is enhanced by the contraction of the finish portion diameter. A corresponding method includes an application step.

1 . A retortable container package comprising: 
 a container including a finish portion that terminates in a circular lip, a taper is formed on an inboard side of the finish portion and merges into the lip, the taper in transverse cross section forms an angle of 6° to 14° from vertical; and    a composite closure capable of being applied to the container, the closure including: 
 a circular skirt;  
 a disk-like insert including a peripheral bead, a raised channel inboard of the peripheral bead, and a circular center portion inboard of the channel; the raised channel including an outer wall, a substantially flat top portion, and an inner wall sloped at approximately the same angle as the taper angle; and  
 a sealant disposed in the channel, the sealant being partially deformed upon application of the closure onto the container such that the sealant forms a seal between the closure and each of (i) an outer wall of the finish portion proximate the lip, (ii) the lip, and (iii) the taper;  
   whereby after retorting, the seal between the finish portion taper and the channel inner wall is enhanced by the contraction of the finish portion diameter.    
   
   
       2 . The container package of  claim 1  wherein the taper is spaced apart from the channel inner wall by a gap of between 0.005″ and 0.015″ prior to retorting.  
   
   
       3 . The container package of  claim 2  wherein the gap is between 0.00″ and 0.015″ after retorting.  
   
   
       4 . The container package of  claim 3  wherein the gap is between 0.002″ and 0.010″ after retorting.  
   
   
       5 . The container package of  claim 4  wherein the gap is between 0.003″ and 0.008″ after retorting.  
   
   
       6 . The container package of  claim 1  wherein where the slope of the inner wall of the channel is defined a first point on the inner wall proximate the top portion and a second point on the inner wall proximate the center portion.  
   
   
       7 . The container package of  claim 1  wherein the inner wall of the channel is curved.  
   
   
       8 . The container package of  claim 1  wherein an uppermost portion of the container lip is substantially planar.  
   
   
       9 . The container package of  claim 8  wherein the container finish portion includes a radiused portion between the lip.  
   
   
       10 . The container package of  claim 1  wherein an uppermost portion of the container lip is arcuate.  
   
   
       11 . The container package of  claim 1  wherein an uppermost portion of the container lip forms and angle of between 1° and 12° from the horizontal.  
   
   
       12 . The container package of  claim 11  wherein an uppermost portion of the container lip forms and angle of between 2° and 8° from the horizontal.  
   
   
       13 . The container package of  claim 1  wherein an uppermost portion of the container lip forms and angle of between 2° and 5° from the horizontal.  
   
   
       14 . The container package of  claim 1  wherein the sealant is groove-less prior to application of the closure to the container.  
   
   
       15 . The container package of  claim 1  wherein the channel outer wall is sloped.  
   
   
       16 . The container package of  claim 1  wherein the container is formed of a polypropylene.  
   
   
       17 . A method of forming a container package comprising the steps of: 
 providing a moil-trimmed container that includes a reamed taper on an interior finish portion;    providing a composite closure that includes: 
 a circular skirt;  
 a disk-like insert including a peripheral bead, a raised channel inboard of the peripheral bead, and a circular center portion inboard of the channel; the raised channel including an outer wall, a substantially flat top portion, and an inner wall sloped at approximately the same angle as the taper angle; and  
 a sealant disposed in the channel;  
   applying the closure to the container such that the sealant is deformed by the container finish portion such that the sealant forms a seal between the closure and each of (i) an outer wall of the finish portion proximate the lip, (ii) the lip, and (iii) the taper; and    retorting the container package such that the container finish decreases in diameter to diminish a gap between the finish portion taper and the channel inner wall to enhance the seal therebetween.    
   
   
       18 . The method of  claim 17  wherein the step of providing the container includes providing a container having blow-molded threads.  
   
   
       19 . The method of  claim 17  wherein the taper in cross section forms an angle of 6° to 14° from vertical.  
   
   
       20 . The method of  claim 19  wherein the taper is spaced apart from the channel inner wall by a gap of between 0.005″ and 0.015″ prior to retorting.  
   
   
       21 . The method of  claim 20  wherein the gap is between 0.00″ and 0.015″ after retorting.  
   
   
       22 . The method of  claim 20  wherein the gap is between 0.002″ and 0.010″ after retorting.  
   
   
       23 . The method of  claim 20  wherein the gap is between 0.003″ and 0.008″ after retorting.  
   
   
       24 . The method of  claim 17  wherein an uppermost portion of the container lip is substantially planar.  
   
   
       25 . The method of  claim 24  wherein the container finish portion includes a radiused portion between the lip.  
   
   
       26 . The method of  claim 17  wherein an uppermost portion of the container lip is arcuate.  
   
   
       27 . The method of  claim 17  wherein an uppermost portion of the container lip forms and angle of between 1° and 12° from the horizontal.  
   
   
       28 . The container package of  claim 11  wherein an uppermost portion of the container lip forms and angle of between 2° and 8° from the horizontal.  
   
   
       29 . The method of  claim 17  wherein an uppermost portion of the container lip forms and angle of between 2° and 5° from the horizontal.  
   
   
       30 . The method of  claim 17  wherein the sealant is groove-less prior to application of the closure to the container.  
   
   
       31 . The container package of  claim 1  wherein the container is formed of a polypropylene.