Packaging laminate for a packaging container, as well as a packaging container produced from the packaging laminate

Abstract

A packaging laminate for a retortable packaging container which comprises a paper or paperboard layer and outer, liquid-tight, heat-resistant layers of plastic on both sides of the paper or paperboard layer. Between the paper or paperboard layer and the outer plastic layer, the packaging laminate has at least one additional layer of a material possessing tightness properties vis-à-vis gases. In order to improve the preconditions for providing the packaging laminate with decorative artwork of printing ink with good print quality, the paper or paperboard layer has, on its one side, a printable coating of pigment and binder or adhesive, and on its other side a coating of starch.

1 . A packaging laminate for a packaging container provided with decorative artwork and produced from a prefabricated, flat folded packaging blank of the packaging laminate, in that the packaging blank is first raised to an open, tubular container carton whose one end is sealed by fold forming and thermosealing of the corresponding foldable end panels of the container carton, for the formation of a liquid-tight, substantially planar bottom closure, whereafter the container carton provided with the bottom is filled with a food and the other end of the thus filled container carton is sealed by an additional fold forming and thermosealing of the corresponding foldable end panels of the container carton, for the formation of a liquid-tight, substantially planar top closure, the packaging laminate including a paper or paperboard layer whose one side has a printable coating of pigment and binder or adhesive in contact with the paper or paperboard layer with decorative artwork of printing ink applied by a suitable printing technology on the printable coating, wherein the other side of the paper or paperboard layer has a coating of starch in contact with the paper or paperboard layer. 
     
     
         2 . The packaging laminate as claimed in  claim 1 , wherein the coating of starch is of a thickness or coating quantity of less than 10 g/m 2 . 
     
     
         3 . The packaging laminate as claimed in  claim 1 , further comprising outer, liquid-tight, heat-resistant layers of plastic on both sides of the paper or paperboard layer. 
     
     
         4 . The packaging laminate as claimed in  claim 3 , wherein the outer, liquid-tight plastic layers are selected from the group essentially comprising high density polyethylene, linear low density polyethylene, polypropylene and polyester. 
     
     
         5 . The packaging laminate as claimed in  claim 1 , further comprising a layer of a material possessing tightness properties vis-à-vis gases. 
     
     
         6 . The packaging laminate as claimed in  claim 5 , wherein the layer possessing gas tightness properties is an aluminium foil. 
     
     
         7 . A parallelepipedic packaging container of the type which, after filling and sealing, is to be subjected to a shelf-life-extending heat treatment in a retort with steam as heat medium, the packaging container being produced from a prefabricated, flat folded packaging blank of a packaging laminate as claimed in  claim 1 , in that the packaging blank is first raised to an open, tubular container carton whose one end is sealed by fold forming and thermosealing of the corresponding foldable end panels of the container carton, for the formation of a liquid-tight, substantially planar bottom closure, whereafter the container carton, provided with the bottom, is filled with a food and the other end of the thus filled container carton is sealed by an additional fold forming and thermosealing of the corresponding foldable end panels of the container carton, for the formation of a liquid-tight, substantially planar top closure. 
     
     
         8 . The packaging laminate as claimed in  claim 1 , wherein the coating of starch is of a thickness or coating quantity of less than 5 g/m 2 . 
     
     
         9 . The packaging laminate as claimed in  claim 1 , wherein the coating of starch is of a thickness or coating quantity of 3 g/m 2 . 
     
     
         10 . The packaging laminate as claimed in  claim 1 , further comprising a layer of a material possessing tightness properties vis-à-vis oxygen gas.