Collapsible bag for dispensing liquids and method

Abstract

A collapsible bag for dispensing liquids, including viscous liquids such as syrup and the like, comprising a first wall, a second wall, a spout, a surface variation associated with the first wall. The first wall and second wall are connected together to define a fluid chamber therebetween. The first wall and the second wall each have an inner surface facing the fluid chamber and an opposed outer surface. The spout is attached to one of the first and second walls, and has an opening therethrough having an axis substantially perpendicular to the one of the first and second walls to which it is attached. The surface variation is molded into at least a portion of the first wall. The surface variation limits contact between the inner surfaces of the first wall and the second wall so as to define a minimum unstressed volume therebetween wherein at least a portion of the minimum unstressed volume is maintained substantially throughout evacuation of liquid therefrom by suction.

1 . A collapsible bag for dispensing liquids, including viscous liquids such as syrup and the like, comprising:
 a first wall and a second wall connected together to define a fluid chamber therebetween, the first wall and the second wall each having an inner surface facing the fluid chamber and an opposed outer surface;   a spout attached to one of the first and second walls, the spout having an opening therethrough having an axis substantially perpendicular to the one of the first and second walls to which it is attached; and   a surface variation molded into at least a portion of the first wall, the surface variation limiting contact between the inner surfaces of the first wall and the second wall so as to define a minimum unstressed volume therebetween, wherein at least a portion of the minimum unstressed volume is maintained substantially throughout evacuation of liquid therefrom by suction.   
   
   
       2 . The collapsible bag of  claim 1  wherein the minimum unstressed volume between the first and second walls is at least 0.18 cubic centimeters per square inch of surface area of each of the first wall and the second wall. 
   
   
       3 . The collapsible bag of  claim 1  wherein the second wall is substantially planar, and wherein the spout is attached to the second wall. 
   
   
       4 . The collapsible bag of  claim 1  wherein the first wall and the second wall each comprise a plurality of layers, a first layer of which comprises a heat sealable polymer material and a second layer of which comprises a polymer material having a relative strength greater than that of the first layer. 
   
   
       5 . The collapsible bag of  claim 4  wherein the first layer comprises a linear low density polyethylene and the second layer comprises a high density polyethylene. 
   
   
       6 . The collapsible bag of  claim 4  wherein the second layer comprises one of the group selected from nylon, high density polyethylene, polypropylene and polyesters. 
   
   
       7 . The collapsible bag of  claim 1  wherein the thickness of each of the first and second walls is less than 10 mils. 
   
   
       8 . The collapsible bag of  claim 7  wherein the thickness of each of the first and second walls is less than 8 mils. 
   
   
       9 . The collapsible bag of  claim 1  wherein the first wall and the second wall each have a strength defined by a secant modulus of at least 30,000 psi. 
   
   
       10 . The collapsible bag of  claim 1  wherein the first wall and the second wall each have a strength defined by a secant modulus of at least 45,000 psi. 
   
   
       11 . The collapsible bag of  claim 1  wherein the surface variation defines a height of the inner surface of the first wall that is between 1.3 and 2.5 times that of the thickness of the first wall. 
   
   
       12 . The collapsible bag of  claim 1  wherein the surface variation comprises a repeated pattern of nested alternating elongated ridges defining a plurality of peaks and valleys, wherein adjoining ridges are disposed obliquely relative to each other. 
   
   
       13 . The collapsible bag of  claim 12  wherein the adjoining ridges are disposed perpendicular to each other. 
   
   
       14 . The collapsible bag of  claim 12  wherein each of the elongated ridges has a substantially hemispherical cross-section along at least a portion thereof. 
   
   
       15 . The collapsible bag of  claim 12  wherein each of the elongated ridges has a length of between 0.0625 inches and 0.1825 inches. 
   
   
       16 . The collapsible bag of  claim 1  wherein the surface variation extends substantially along at least 85% of a surface area of the first wall. 
   
   
       17 . The collapsible bag of  claim 1  wherein the surface variation extends substantially along the entirety of the first wall. 
   
   
       18 . The collapsible bag of  claim 4  wherein the first and second walls further comprise a third layer positioned on the second layer opposite the first layer, the third layer comprising a polymer material. 
   
   
       19 . The collapsible bag of  claim 18  wherein the third layer comprises a linear low density material of a lower strength than the second layer. 
   
   
       20 . The collapsible bag of  claim 1  further comprising an outer first wall and an outer second wall, the outer first wall being positioned on the first wall and the outer second wall positioned on the second wall so as to define a two-ply collapsible bag. 
   
   
       21 . The collapsible bag of  claim 1  wherein the spout further comprises:
 an elongated opening; and   a base flange extending about the elongated opening;   the flange having a bottom surface, wherein the bottom surface includes a plurality of surface channels positioned thereon.   
   
   
       22 . The collapsible bag of  claim 21 , wherein the plurality of surface channels comprise radial grooves. 
   
   
       23 . The collapsible bag of  claim 21 , wherein the plurality of surface channels comprise a combination of a plurality of concentric circular grooves and a plurality of radial grooves. 
   
   
       24 . The collapsible bag of  claim 22  wherein the bottom surface of the flange includes a plurality gussets positioned proximate the elongated opening. 
   
   
       25 . The collapsible bag of  claim 22  wherein a plurality of gussets are positioned between pairs of radial grooves. 
   
   
       26 . The collapsible bag of  claim 22  wherein a plurality of recesses are formed on the bottom surface of the flange proximate the elongated opening. 
   
   
       27 . A collapsible bag for dispensing liquids, comprising:
 a first wall and a second wall connected together to define a fluid chamber therebetween, the first wall and the second wall each having an inner surface facing the fluid chamber and an opposed outer surface, each of the first and second walls comprising at least two layers, a first layer and a second layer, wherein the second layer has a rigidity greater than that of the first layer;   a spout attached to one of the first and second walls, the spout having an opening therethrough having an axis substantially perpendicular to the one of the first and second walls to which it is attached;   a surface variation molded into at least a portion of the first wall, the surface variation limiting contact between the inner surfaces of the first wall and the second wall, wherein the surface variation exceeds the thickness of the underlying first wall upon which it is positioned, wherein at least a portion of the minimum unstressed volume is maintained substantially throughout evacuation thereof by suction.   
   
   
       28 . The collapsible bag of  claim 27  wherein the surface variation defines a minimum unstressed volume therebetween of at least 0.18 cubic centimeters per square inch of surface area of each of the first wall and the second wall. 
   
   
       29 . The collapsible bag of  claim 27  wherein the liquid comprises a viscous liquid such as syrup and the like.