Permeability Cups

Permeability Cups

Permeability Cups are BYK-Gardner testing instruments used to evaluate film permeability to water vapor or vapor transmission in paints, coatings, varnishes, plastic films, cloth, coated papers, and other film materials. This test helps users understand a layer or film’s ability to resist or transmit water vapor, making it important for coating, packaging, protective film, and barrier material applications.

In permeability testing, the film sample is mounted on a cup containing desiccant or a defined test medium, then the cup weight change is monitored during the test period. This weight change is used to calculate the rate of water vapor transfer through the sample. The method is useful for evaluating water vapor transmission, moisture barrier performance, coating protection, and material consistency in quality control and R&D processes.

BYK-Gardner Permeability Cups are available in two exposed area sizes: 25 cm?2; for ASTM standard requirements and 10 cm?2; for smaller samples with reduced desiccant use. The cup includes a rubber gasket to provide an excellent seal and knurled side edges for easier tightening and opening. This product is suitable for testing paint films, varnish films, plastic films, coated papers, textiles, protective coatings, packaging materials, and water vapor permeability according to ASTM D1653 and ISO 7783-2.