Multilayer sheet of liner for packaging hot foods

Abstract

The present invention discloses a multilayer sheet for packaging hot foods especially useful in the “take-out” market. The multilayer sheet has two, and optionally three, layers. The first inner layer comprises a water-wicking material, preferably a nonwoven with a moisture-vapor transmission rate (MVTR) of at least about 20,000 g/m 2 -day and a hydrostatic head pressure of less than about 5 cm H 2 O. The second layer comprises a somewhat absorbent and highly-thermally insulating material. The multilayer sheet may be used in various packaging embodiments, e.g., as a wrap, pouch or bag, etc. The multilayer sheet maintains freshly-cooked food quality by improving heat retention and moisture control.

1 . A article comprising at least two layers including a first layer, a second layer, and optionally a third layer wherein the article is a multilayer sheet or a liner; the first layer comprises or is produced from a water-wicking material; the second layer comprises or is produced from an absorbent and insulating material; the third layer comprises or is produced from a structural material; and the article optionally comprises an additive including a desiccant, thermal and ultraviolet (UV) stabilizer, UV absorber, antistatic agent, processing aid, fluorescent whitening agent, pigment, lubricant, or combinations of two or more thereof.  
   
   
       2 . The article of  claim 1  wherein the first layer has a moisture-vapor transmission rate of at least about 20,000 g/m 2 -day.  
   
   
       3 . The article of  claim 1  wherein the first layer has a moisture-vapor transmission rate of at least about 150,000 g/m 2 -day.  
   
   
       4 . The article of  claim 1  wherein the first layer has a hydrostatic head pressure of less than about 5 cm H 2 O.  
   
   
       5 . The article of  claim 4  wherein the first layer has a moisture-vapor transmission rate of at least about 20,000 g/m 2 -day and a moisture-vapor transmission rate of at least about 170,000 g/m 2 -day.  
   
   
       6 . The article of  claim 5  wherein the first layer is, or is produced from, a nonwoven.  
   
   
       7 . The article of  claim 6  wherein the nonwoven comprises a spunlaced fabric comprising a mixture of fibers of poly(ethylene terephthalate) and wood pulp.  
   
   
       8 . The article of  claim 1  wherein the second layer has a thermal resistance, as measured in units of insulation, of at least about 0.0077 m 2. K/W (0.05 CLO).  
   
   
       9 . The article of  claim 7  wherein the second layer has a thermal resistance, as measured in units of insulation, of at least about 0.0077 m 2. K/W (0.05 CLO).  
   
   
       10 . The article of  claim 8  wherein the second layer comprises fiberfill batt, melt-blown fibers, foam, knit material, felt, or combinations of two or more thereof.  
   
   
       11 . The article of  claim 9  wherein the second layer comprises fiberfill batt, melt-blown fibers, foam, knit material, felt, or combinations of two or more thereof.  
   
   
       12 . The article of  claim 9  wherein the second layer comprises the fiberfill batt, which comprises or is produced from poly(ethylene terephthalate).  
   
   
       13 . The article of  claim 12  wherein the second layer ranges in thickness from about 10 mils to about 500 mils.  
   
   
       14 . The article of  claim 13  comprising the third layer and the structural material is oriented polypropylene, oriented polyester, or combinations thereof.  
   
   
       15 . The article of  claim 14  wherein the first layer is a nonwoven comprising a spunlaced fabric having a moisture-vapor transmission rate of at least about 20,000 g/m 2 -day and a hydrostatic head pressure of less than about 5 cm H 2 O, and the second layer has a thermal resistance of at least about 0.0077 m 2. K/W (0.05 CLO).  
   
   
       16 . The article of  claim 15  wherein the spunlaced fabric comprises a mixture of fibers of poly(ethylene terephthalate) and wood pulp, and the second layer is fiberfill batt.  
   
   
       17 . A packaging wrap, bag, or pouch comprising or produced from a multilayer sheet wherein the multilayer sheet is as recited in  claim 1 .  
   
   
       18 . The packaging wrap, bag, or pouch of  claim 17  wherein the multilayer sheet is as recited in  claim 16 .  
   
   
       19 . A process comprising laminating, by contacting under suitable pressure and heat, a first layer to a second layer wherein the first layer and the second layer are each as recited in  claim 1 .  
   
   
       20 . The process of  claim 19  wherein the first layer and the second layer are each as recited in  claim 15 .  
   
   
       21 . The process of  claim 19  comprising interposing a layer of a thermoplastic adhesive scrim between the first layer and the second layer, and laminating the first layer to the second layer.  
   
   
       22 . The process of  claim 21  wherein the first layer and the second layer are each as recited in  claim 15 .  
   
   
       23 . The process of  claim 21  further comprising, prior to laminating, interposing a layer of a thermoplastic adhesive scrim between the second layer and a third layer, which is as recited in  claim 14.