Test method for determination of moisture vapor transmission rate
AssigneeW. L. Gore & Associates, Inc.
InventorPhilip M. Crosby
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Abstract
A method is described for determining the degree of moisture vapor transmission of certain materials which comprises taking a weighed test cup containing a saturated salt solution sealed inside the cup with a waterproof, moisture vapor permeable membrane, and inserting it over a sample that is supported on a waterproof, moisture vapor permeable membrane over a controlled temperature waterbath. After a set time, the cup is reweighed and the water pick up recorded.
Claims2
A method for determining the degree of moisture vapor transmission of certain materials that transmit water in amounts that affect moisture vapor transmission values, which comprises, in sequence:
- (i) placing a sample of the material onto a waterproof, moisture vapor permeable membrane in a support on a controlled temperature water bath held at a temperature that is substantially the same as the test environment,
- (ii) inverting a weighed test cup which contains a saturated salt solution and is sealed with a waterproof, moisture vapor permeable membrane onto the sample, said salt having an equilibrium relative humidity higher than that of the atmosphere in which the method is carried out, and in which a solution of the salt is free flowing at ambient conditions,
- (iii) after a predetermined time, weighing the cup and recording the water pickup over the weight of the cup prior to step ii,
- (iv) determining the moisture vapor transmission rate.
Dependencies are inferred from the claim text.