Water Vapor Transmission Rate (WVTR)

We use the PERMATRAN-W©3/31 testing system to assess barrier materials used in packaging applications. We can adapt the conditions (temperature, relative humidity, flow, etc.) to better fit the real and extreme conditions. Flexibility is the key word.

Product packaging and shelf-life considerations can best be determined when accurate testing is employed. All testing is not alike, and with today's high barrier materials, it is very important to get the optimum packaging material, at the best cost. Barrier materials selection, material thickness, composite designs, package configuration, seal/cap design, and the product itself will all affect the water vapor transmission rate, a common problem in food and pharmaceutical packaging. Material testing for WVTR will assure you that product shelf-life and certain package characteristics will meet your specification when introduced to the market ... and still meet the budget.

Flat film samples are clamped into the diffusion cell, which is then purged of residual water vapor using moisture-free carrier gas. This moisture – free carrier gas is routed to the sensor until a stable WVTR has been established. Molecules of water diffusing through the film to the inside chamber are conveyed to the sensor by the carrier gas.

Operating Principle

The computer monitors the increase in water vapor concentration in the carrier gas and it reports the value on the screen as the vapor transmission rate.

WVTR Test Range

Oxygen Transmission Rate

Today's test environment demands a system that delivers precise transmission rates data and is adaptable to changing requirements. We use computer controlled OX-TRAN 2/20 system. We provide various capabilities and combinations of temperature control and barometric pressure options.

Setting the worldwide standard for permeation testing, the OX-TRAN2/20 system uses a patented coulometric sensor (COULOX ®) to detect oxygen transmission through both flat materials and packages. This high performance sensor provides sensitivity even in the presence of the water vapor.

Flat film samples are clamped into the diffusion cell, which is then purged of residual oxygen using an oxygen-free carrier gas. The carrier gas is routed to the sensor until a stable zero has been established. Pure (99.9%) oxygen is then introduced into the outside chamber of the diffusion cell. Molecules of oxygen diffusing through the film to the inside chamber are conveyed to the sensor by the carrier gas. As the sensor generates an electrical current directly proportional to the amount of oxygen in the carrier gas, the computer monitors the increase in current across a load resistor. The computer reports that value on screen as the oxygen transmission rate.

Operating Principle

OTR Test Range