Paper material with total closure particularly for use in the food industry

Abstract

The paper material includes a base support having a mixture of cellulose fibres and other natural and/or synthetic fibres, at least one polymeric substance adapted to confer to the base support mechanical resistance, water resistance and a functional barrier to water, fats, oils and gases, and an inorganic filler, the base support having a porosity comprised between 50 and 20000 sec according to the Gurley method and being coated with at least one surface coat having as adhesive at least one silicone from 0.1% by weight to 5% by weight of the paper material, adapted to confer to the coat functional barrier properties to water, fats, oils and gases, mechanical resistance and the ability to fold without tearing.

1 - 10 . (canceled) 
     
     
         11 . A paper material comprising a base support comprising a mixture of cellulose fibres and other natural and/or synthetic fibres, at least one polymeric substance adapted to confer to the base support mechanical resistance, water resistance and a functional barrier to water, fats, oils and gases, and an inorganic filler, said base support having a porosity comprised between 50 and 20000 sec according to the Gurley method and being coated with at least one surface coat comprising, as an adhesive, at least one silicone from 0.1% by weight to 5% by weight of the paper material adapted to confer to the coat functional barrier properties to water, fats, oils and gases, mechanical resistance and the ability to fold without tearing. 
     
     
         12 . The paper material according to  claim 11 , wherein said coat further includes, as an adhesive, at least one of a starch, a polyol, an acrylic polymer, a polyurethane polymer, a synthetic or natural wax. 
     
     
         13 . The paper material according to  claim 11 , wherein said fibre mixture comprises cellulose fibres, cotton fibres and synthetic fibres. 
     
     
         14 . The paper material according to  claim 11 , wherein at least one said polymeric substance comprises one or more colophony-based and/or alkyl-ketene-dimer-based and/or acetyl succinic-acid-based and/or epochlorohydrin-based and/or carboxymethylcellulose-based resins. 
     
     
         15 . The paper material according to  claim 11 , wherein said inorganic filler is a mineral filler comprising one or more substances selected from the group consisting of carbonates, kaolins, talc and mixtures thereof. 
     
     
         16 . The paper material according to  claim 11 , having the following percentage composition referred to the weight of the paper material:
 cellulose fibres in the base support between 50% and 90% by weight;   natural and/or synthetic fibres in the base support between 1% and 10% by weight;   polymeric substance in the base support between 1% and 10% by weight;   inorganic filler in the base support between 2% and 40% by weight; and   adhesive in the coat between 1% and 12% by weight including silicone between 0.1% and 5% by weight.   
     
     
         17 . The paper material according to  claim 11 , wherein a grammage of the paper material is comprised between 50 gr/m 2  and 900 g/m 2 . 
     
     
         18 . A method for manufacturing a paper material according to  claim 11 , the method including the following steps:
 preparing an aqueous pulp containing said cellulose fibres and other natural and/or synthetic fibres, said at least one polymeric substance and said inorganic filler,   removing water from the pulp so as to form said base support of the paper material, and   applying said coat to said base support by treating at least one surface of said base support with at least one solution comprising at least said silicone as an adhesive.   
     
     
         19 . The method for manufacturing a paper material according to  claim 18 , wherein after the application of said coat, a smoothing step is carried out up to Bendtsen ISO 2494 smoothness values less than about 400 ml/min. 
     
     
         20 . A layer of paper material according to  claim 11 , coupled to containers in the form of a bag containing liquids or gels.