Permeability testing apparatus and method

Claim 2

Apparatus for measuring film permeability using flowing gas streams including a gastight cell comprised of a pair of sections adapted to clamp a sheet of film material therebetween and thereby partition the cell into first and second compartments, means to connect the first compartment with a sweep gas source, and means to connect the second compartment with a test gas source, and exhaust outlet in each of said compartments and a test gas detecting element in communication with the exhaust of said first compartment to determine the amount of test gas present in the exhaust of the first compartment per unit of time.

Claim 3

Apparatus for measuring film permeability as defined in claim 1 wherein the sweep gas is a dry gas and the test gas is water saturaTed, and the detector element comprises means for determining the amount of water vapor present in the exhaust of the first compartment per unit of time to measure the water vapor permeability of the test film.

Claim 4

An apparatus as defined in claim 2 wherein the test gas is rendered water saturated by a saturator element at the test gas source, and means to bypass said saturator element to enable introduction into the second chamber unsaturated gas for establishing a base reading on the detector.

Claim 5

An apparatus as defined in claim 1 wherein said first and second sections of the cell have abutting flanges that include mated ridges that firmly grip the test film positioned therebetween to tightly seal the compartments against atmospheric leakage, and means for measuring and adjusting the gas pressure within the compartments.

Claim 6

A process for measuring the permeability of films using flowing gas streams which includes passing a sweep gas over one side of sheet of film material while simultaneously passing a test gas over the other side of the sheet, and measuring the amount of test gas present in the spent sweep gas per unit of time to determine the rate at which the test gas permeates through the film.

Claim 7

A process for measuring the permeability of films using flowing gas streams which includes passing a sweep gas over one side of sheet of film material while simultaneously passing a test gas over the other side of the sheet, and measuring the amount of test gas present in the spent sweep gas per unit of time to determine the rate at which the test gas permeates through the film.

Claim 8

A process for measuring the permeability of films using flowing gas streams to water vapor which includes passing a dry gas over one side of a sheet of film material while simultaneously passing a saturated gas over the other side of the sheet, and measuring the water content in the spent sweep gas per unit of time to determine the rate at which the water vapor permeates through the film.

Claim 9

A process for measuring the permeability of films using flowing gas streams to water vapor which includes passing a dry gas over one side of a sheet of film material while simultaneously passing a saturated gas over the other side of the sheet, and measuring the water content in the spent sweep gas per unit of time to determine the rate at which the water vapor permeates through the film.

Claim 10

The process according to claim 6, wherein said dry gas is obtained by passing a gas over phosphorous pentoxide to absorb moisture therefrom and subjecting said absorbed moisture to electrolysis.

Claim 11

The process according to claim 7, wherein said water content in said spent sweep gas is absorbed by phosphorous pentoxide, the resulting absorbed moisture is electrolyzed, and the resulting electrolysis current is measured to determine said rate at which said water vapor permeates through said film.

Claim 12

Apparatus for measuring the moisture vapor transmission characteristic of material comprising: first and second members forming first and second closed chambers adapted to be separated by a layer of the material disposed with a surface in each chamber, each of said chambers having an inlet and an outlet passage, a first gas supply means for providing a constant flow of gas at a predetermined temperature and pressure and with a predetermined moisture content, means connecting said first supply means to said inlet passage of the first chamber to provide a constant flow of gas through said first chamber and across one surface of the material, a second gas supply means for providing a constant flow of gas at a predetermined temperature and pressure and with a predetermined moisture content, the gas of said second supply means having a moisture content lower than the gas of said first supply means, means connecting said second supply means to said inlet passage of the second chamber to provide a constant flow of gas through said second chamber and across another surface of the material, and means connected to said outlet passage of said second chamber for indicating the gain in moisture level of the gas as it passes through said second chamber and gains the moisture which has passed through the material to provide an indication of the moisture permeability of the material.

Claim 13

Apparatus for measuring the moisture vapor transmission characteristic of material comprising: first and second members forming first and second closed chambers adapted to be separated by a layer of the material disposed with a surface in each chamber, each of said chambers having an inlet and an outlet passage, a first gas supply means for providing a constant flow of gas at a predetermined temperature and pressure and with a predetermined moisture content, means connecting said first supply means to said inlet passage of the first chamber to provide a constant flow of gas through said first chamber and across one surface of the material, a second gas supply means for providing a constant flow of gas at a predetermined temperature and pressure and with a predetermined moisture content, the gas of said second supply means having a moisture content lower than the gas of said first supply means, means connecting said second supply means to said inlet passage of the second chamber to provide a constant flow of gas through said second chamber and across another surface of the material, and means connected to said outlet passage of said second chamber for indicating the gain in moisture level of the gas as it passes through said second chamber and gains the moisture which has passed through the material to provide an indication of the moisture permeability of the material.

Claim 14

Apparatus for measuring the moisture vapor transmission characteristic of material comprising: first and second members forming first and second closed chambers adapted to be separated by a layer of the material disposed with a surface in each chamber, each of said chambers having an inlet and an outlet passage, a first gas supply means for providing a constant flow of gas at a predetermined temperature and pressure and with a predetermined moisture content, meaNs connecting said first supply means to said inlet passage of the first chamber to provide a constant flow of gas through said first chamber and across one surface of the material, a second gas supply means for providing a constant flow of gas at a predetermined temperature and pressure and with a predetermined moisture content, the gas of said second supply means having a moisture content lower than the gas of the first supply means, means connecting said second supply means to said inlet passage of the second chamber to provide a constant flow of gas through said second chamber and across another surface of the material, and means connected to said outlet passage of said second chamber for indicating the gain in moisture level of the gas which has passed through said second chamber and gained the moisture which has passed through the material to provide an indication of the moisture permeability of the material.

Claim 15

Apparatus for measuring the moisture vapor transmission characteristic of material comprising: first and second members forming first and second closed chambers adapted to be separated by a layer of the material disposed with a surface in each chamber, each of said chambers having an inlet and an outlet passage, a first gas supply means for providing a constant flow of gas at a predetermined temperature and pressure and with a predetermined moisture content, meaNs connecting said first supply means to said inlet passage of the first chamber to provide a constant flow of gas through said first chamber and across one surface of the material, a second gas supply means for providing a constant flow of gas at a predetermined temperature and pressure and with a predetermined moisture content, the gas of said second supply means having a moisture content lower than the gas of the first supply means, means connecting said second supply means to said inlet passage of the second chamber to provide a constant flow of gas through said second chamber and across another surface of the material, and means connected to said outlet passage of said second chamber for indicating the gain in moisture level of the gas which has passed through said second chamber and gained the moisture which has passed through the material to provide an indication of the moisture permeability of the material.

Claim 16

Apparatus for measuring the permeability of material to a test gas, comprising: first and second members forming first and second closed chambers adapted to be separated by a layer of the material disposed with a surface in each chamber, each of said chambers having an inlet and an outlet passage. a first gas supply means for providing a constant flow of a first gas at a predetermined temperature and pressure and with a predetermined content of said test gas, means connecting said first supply means to said inlet passage of the first chamber to provide a constant flow of gas through said first chamber and across one surface of the material, a second gas supply means for providing a constant flow of gas at a predetermined temperature and pressure and with a predetermined content of said test gas, the content of said test gas provided by said second supply means being lower than that of said test gas provided by the first supply means, means connecting said second supply means to said inlet passage of the second chamber to provide a constant flow of gas through said second chamber and across another surface of the material, and means connected to said outlet passage of said second chamber for indicating the content of test gas in the gas which has passed through said second chamber and gained test gas which has passed through the material to provide an indication of the permeability of the material to said test gas.

Claim 17

Apparatus for measuring the permeability of material to a test gas, comprising: first and second members forming first and second closed chambers adapted to be separated by a layer of the material disposed with a surface in each chamber, each of said chambers having an inlet and an outlet passage. a first gas supply means for providing a constant flow of a first gas at a predetermined temperature and pressure and with a predetermined content of said test gas, means connecting said first supply means to said inlet passage of the first chamber to provide a constant flow of gas through said first chamber and across one surface of the material, a second gas supply means for providing a constant flow of gas at a predetermined temperature and pressure and with a predetermined content of said test gas, the content of said test gas provided by said second supply means being lower than that of said test gas provided by the first supply means, means connecting said second supply means to said inlet passage of the second chamber to provide a constant flow of gas through said second chamber and across another surface of the material, and means connected to said outlet passage of said second chamber for indicating the content of test gas in the gas which has passed through said second chamber and gained test gas which has passed through the material to provide an indication of the permeability of the material to said test gas.

Claim 18

Apparatus for measuring the moisture vapor transmission of a film of material, comprising: first and second members forming first and second closed chambers adapted to be separated by said film with a surface in each chamber, each of said chambers having an inlet and an outlet passage; a first gas supply means for providing a first gas with a predetermined moisture content; means connecting said first gas supply means to said inlet passage of said first chamber; a second gas supply means for providing a second gas; drying means connected to said second gas supply means to dry said second gas and provide a dry gas having a moisture content lower than that of said first gas; means connecting said drying means to said inlet passage of said second chamber; and means connected to said outlet passage of said second chamber for indicating the gain in moisture level of the gas which has passed through said second chamber and gained the moisture which has passed through said film to provide an indication of the moisture permeability of the material.

Claim 19

Apparatus for measuring the moisture vapor transmission of a film of material, comprising: first and second members forming first and second closed chambers adapted to be separated by said film with a surface in each chamber, each of said chambers having an inlet and an outlet passage; a first gas supply means for providing a first gas with a predetermined moisture content; means connecting said first gas supply means to said inlet passage of said first chamber; a second gas supply means for providing a second gas; drying means connected to said second gas supply means to dry said second gas and provide a dry gas having a moisture content lower than that of said first gas; means connecting said drying means to said inlet passage of said second chamber; and means connected to said outlet passage of said second chamber for indicating the gain in moisture level of the gas which has passed through said second chamber and gained the moisture which has passed through said film to provide an indication of the moisture permeability of the material.

Claim 20

Apparatus according to claim 12, wherein said drying means comprises a phosphorous pentoxide electrolytic cell.

Claim 21

Apparatus according to claim 12, wherein said means for indicating comprises a phosphorous pentoxide electrolytic cell and means for measuring the electrolysis current of the latter cell.

Claim 22

Apparatus according to claim 12, wherein said first gas supply means comprises a water saturator for saturating a carrier gas with water to provide said first gas.

Claim 23

Apparatus according to claim 12 further comprising bypass means for passing said dry gas to said inlet passage of said first chamber.