Continuous motion rotating thermoforming of soluble pouches

Abstract

A method of making a pouch from webs that include soluble polymeric substrates includes, among other steps, rotating a former that includes a plurality of cavities around its periphery and one or more heaters around the former for heating the cavities and heating the cavities. A base web is drawn into the cavities with a vacuum to form pockets in the base web, after which the pockets are filled and closed.

What is claimed is: 
     
         1 . A method of making a pouch from two webs comprising soluble polymeric substrates, the method comprising the steps of:
 rotating a former that comprises a plurality of cavities around its periphery and one or more heaters around the former for heating the cavities;   heating the cavities;   drawing a base web into the cavities by means of a vacuum to form pockets in the base web;   filling the pockets with at least one component;   closing the pockets with a top web to form a pouch; and   heating the cavities and maintaining the vacuum after the step of drawing the base web into the cavities in order that, once thermoformed, the base web is held tightly to a base of the cavities through filling, sealing and cutting stations until the vacuum is released and the filled and sealed pouch is ejected from its cavity.   
     
     
         2 . The method of  claim 1 , wherein the pouches are water soluble and a dissolution temperature of the base and top webs is identical. 
     
     
         3 . The method of  claim 1 , wherein the pouches are water soluble and a dissolution temperature of the base and top webs is different. 
     
     
         4 . The method of  claim 1 , wherein the pouches contain one or more components selected from the group consisting of a granular product, a powder product, a gel, a liquid, and a three-dimensional solid item. 
     
     
         5 . The method of  claim 1 , wherein the base web is perforated or porous. 
     
     
         6 . The method of  claim 1 , further comprising the step of applying a coating on a face of one or more of said webs. 
     
     
         7 . The method of  claim 6 , wherein the coating is selected from the group consisting of a colouring, a perfume, a concentrate, and an active ingredient. 
     
     
         8 . The method of  claim 1 , wherein the one or more heaters comprise a plurality of heaters that are configured to heat the cavities before and after drawing the base web into the cavities. 
     
     
         9 . The method of  claim 1 , further comprising applying different levels of vacuum at different positions around the former. 
     
     
         10 . The method of  claim 1 , further comprising pressing the top web and base web together at the sealing station such that the webs are securely sealed around a periphery of the filled pouches using a combination of heat and solvent welding. 
     
     
         11 . A method of making a pouch from three webs comprising soluble polymeric substrates, the method comprising the steps of:
 rotating a former that comprises a plurality of cavities around its periphery and one or more heaters around the former for heating the cavities;   heating the cavities;   drawing a micro-perforated or porous base web into the cavities using a vacuum to form pockets in the base web;   filling the pockets with at least one powder or granular product;   closing the pockets with an intermediate web to create a lower compartment;   evacuating the lower compartment through the micro-perforations or porosity in the base web;   filling the pockets with at least one powder or granular product or liquid or gel product on top of the lower compartment;   closing the pockets with a top web to create an upper compartment; and   heating the cavities and maintaining the vacuum after the step of drawing the base web into the cavities in order that, once thermoformed, the base web is held tightly to a base of the cavities through filling, sealing, and cutting stations until the vacuum is released and the filled and sealed pouch is ejected from its cavity.   
     
     
         12 . The method of  claim 11 , wherein at least one compartment of the pouch contains one or more components selected from the group consisting of a granular product, a powder product, a liquid, a gel, and a three-dimensional solid item. 
     
     
         13 . The method of  claim 12 , wherein at least one compartment of the pouch contains a combination of at least two different components. 
     
     
         14 . The method of  claim 13 , further comprising adding a liquid or gel to at least one of the upper or lower compartment, forming a solid skin on a surface of the liquid or gel, and adding a granular or powder product after the solid skin has formed to prevent the components from mixing. 
     
     
         15 . The method of  claim 11 , wherein the pouches are water soluble and a dissolution temperature of the base and top webs is identical. 
     
     
         16 . The method of  claim 11 , wherein the pouches are water soluble and a dissolution temperature of the base and top webs is different. 
     
     
         17 . The method of  claim 11 , further comprising the step of applying a coating on a face of one or more of said webs. 
     
     
         18 . The method of  claim 17 , wherein the coating is selected from the group consisting of a colouring, a perfume, a concentrate, and an active ingredient. 
     
     
         19 . The method of  claim 11 , wherein the one or more heaters comprise a plurality of heaters configured to heat the cavities before and after drawing the base web into the cavities. 
     
     
         20 . The method of  claim 11 , further comprising applying different levels of vacuum at different positions around the former. 
     
     
         21 . The method of  claim 11 , further comprising pressing the webs together at the sealing station such that a periphery around the filled compartments is securely sealed by a combination of heat and solvent welding.