Wvtr and otr

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WATER VAPOUR TRANSMISSION RATE AND OXYGEN TRANSMISSION RATE TESTING PRINCIPLE

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TRANSMISSION RATE TESTER.

WVTR AND OTR TEST

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)

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

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

• 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

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.

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 

• 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

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.

• 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

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:

• THANK YOU