Valve, and package

Abstract

A pressure-relief valve includes a main body equipped to be fastened to a flexible package material. The main body has at least one through hole forming a passage through the main body. A valve membrane lies, on a package side, against the main body in a region around the hole, and a sealing liquid between the main body and the valve membrane. The valve has a water-soluble polymer, whereby at least one component of the valve, for example the main body, is made of a polymer composition that includes a water-soluble polymer.

1 . Pressure-relief valve, the valve comprising a main body equipped to be fastened to a flexible package material, the main body having at least one through hole forming a passage through the main body, a valve membrane lying against the main body on a package side in a region around the at least one through hole, and a sealing liquid between the main body and the valve membrane, wherein at least one component of the valve is made of a polymer composition comprising a water-soluble polymer. 
     
     
         2 . The valve according to  claim 1 , wherein the polymer composition of the least one component comprises a salt. 
     
     
         3 . The valve according to  claim 1 , wherein at least the main body is made of a polymer composition comprising a water-soluble polymer and a salt. 
     
     
         4 . The valve according  claim 1 , wherein the water-soluble polymer comprises a polymer chain with a plurality of vinyl alcohol groups, wherein the water-soluble polymer is poly(vinyl alcohol) (PVOH). 
     
     
         5 . The valve according to  claim 1 , wherein the valve membrane is made of a material that is water-insoluble. 
     
     
         6 . The valve according to  claim 1 , consisting of materials that are biologically degradable. 
     
     
         7 . The valve according to  claim 1 , further comprising a permeable membrane secured to the main body to cover the at least one through hole on a product side opposite the package side. 
     
     
         8 . The valve according to  claim 7 , wherein the permeable membrane is a fabric made of a polymer composition comprising a water-soluble polymer. 
     
     
         9 . The valve according to  claim 1 , wherein a mouth of the through hole or at least one of the through holes on the product side is offset with respect to an outermost plane defined by a surface of the main body on the product side. 
     
     
         10 . The valve according to  claim 9 , wherein the main body has a system of ventilation grooves, with spacers between them, the mouth of the through hole or the at least one of the through holes being in a ventilation groove. 
     
     
         11 . The valve according to  claim 1 , wherein the main body is cup shaped, with a bottom and a circumferential wall, the valve further comprising a fixing part part fixed relative to the circumferential wall so that the valve membrane is sandwiched between the bottom and the fixing part. 
     
     
         12 . The valve according to  claim 1 , wherein the main body is cup shaped, with a bottom and a circumferential wall, and wherein the bottom, on the package side, has a system of grease grooves for accommodating a portion of the sealing liquid, the system of grease grooves comprising at least one outer grease groove having a main portion running in a circumferential direction and having a radial inward extension extending from the main portion into a radial inward direction. 
     
     
         13 . The valve according to  claim 12 , wherein the system of grease grooves comprises at least one circular array of at least two first outer grease grooves and at least one circular array of at least two second outer grease grooves, the first outer grease grooves being arranged around the second outer grease grooves, and the second outer grease grooves being staggered with respect to the first outer grease grooves. 
     
     
         14 . The valve according to  claim 12 , wherein the system of grease grooves further comprises an inner grease groove extending around the at least one through hole. 
     
     
         15 . A package for packaging food products, the package comprising a flexible, pliant packaging material as well as a pressure relief valve according to  claim 1 , wherein the main body is attached to the packaging material.