WATER VAPOUR TRANSMISSION RATE AND OXYGEN TRANSMISSION RATE TESTING PRINCIPLE

1. TRANSMISSION RATE
TESTER.
WVTR AND OTR TEST

2. Water vapour transmission rate
(WVTR)
• WVTR – time rate of water-vapour flow
normal to two specified parallel surfaces
under steady conditions, through unit
area, under the conditions of the test
• Accepted unit ( 1 gram per 24 h per sq.
meter)

3. WVTR FOR PACKAGING
CONTAINERS
• The water vapour transmission rate (WVTR)
through the container is determined by:
– Container wall thickness
– Permeability of the packaging material
– Difference between the external and internal relative
humidity environments
• Driving force for the water flux through the container

4. TESTING
• Specimens are attached to the top of the
dishes by means of a sealant
• Dishes contain desiccant / water depending
on method
• Complete assemblies are inserted in the
atmosphere and after specific period of
time are weighed accurately to determine
gain or loss.
• Test is conducted until nominal steady state
exists

5. • Permeation rate – (mL.mm)/(m2.24h.atm), dry,
at (temperature 0o)
• Transmission rate – (mL/(m2.24h), dry, at
(temperature 0o)
• Factors affecting permeation rate
– Material thickness
– Relative humidity
– Temperature
– Time
– Barometric pressure
• Test results should are valid only if the barrier
material has reached equilibrium

6. W3/330 Water Vapor Transmission
Rate Test System
• W3/330 system is based on the
electrolytic sensor method to measure
water vapor transmission rate of film and
package specimens. It has
three independent testing cells and can
be easily connected with 9 satellite
systems.

7. Applications of Labthink moisture vapor transmission rate tester:
-- Films
-- Sheeting
-- Paper and Paper Board
-- aluminium foils
-- plastic containers
-- Medical Packages
-- and other materials that used as a barrier material
Features of this moisture vapor transmission rate W3/330:
-- Three testing chambers in one instrument with average value
available
-- Electrolytic sensor method
-- Precise and wide range temperature and humidity control
-- Conform to ASTM, ISO international standards
-- Referral films
-- Professional software

8. • Technical Data:
-- Test Range: 0.1~1,000 g/m2·24h
-- Resolution: 0.001 g/m2·24h
-- Temperature Range: 15°C~55°C
-- Temperature Accuracy: ±0.1°C
-- Humidity Range: 10%RH~98%RH
-- Humidity Accuracy: ±1%RH
Standards:
ISO 15106-3, GB/T 21529, DIN 53122-2,
YBB00092003

9. Oxygen permeation rate (O2TR)
• Oxygen- thief of flavor, texture, color,
nutrition & shelf life
• True shelf life condition tests – able to
control RH% independently on each side of
the material
• Test - coulox sensor
• The coulox oxygen sensor is a fuel cell that
works in accordance with faraday’s law.
When exposed to oxygen, the coulox
sensor generates electrical current
proportional to the amount of oxygen.

10. • Similar considerations are
relevant to protection of
products that are labile to
oxidative degradation.
The permeability of
plastic containers to
oxygen ingress has also
been evaluated (OVTR),
and is summarised here.
Pack OVTR
(g. mm/(m2. day))
LDPE 241
HDPE 102
Polystyrene 127
Polycarbonate 114
Polypropylene 89
PVC 4
PET 2

12. STANDARDS
ASTM D-3985
• Analysis Temp: 23C
• Test Gas:
100% O2 (dry)
• Carrier Gas:
98%N2 / 2%H2 (dry)
• Instrument:
MOCON Oxtran® 2/21
• Methodology:

16. • THANK YOU