What is a good water vapor transmission rate?

Relevance to package performance

Film Type	WVTR @ 100°F (38°C), 90% RH for 1 mil film
(g/100 in2/24 hr)	(g/m2/24 hr)
Biax OPP	0.25 – 0.40	3.9 – 6.2
HPDE (high density polyethylene)	0.3 – 0.5	4.7 – 7.8
Cast PP	0.6 – 0.7	9.3 – 11

What is water transmission rate?

Definition: Water Vapor Transmission Rate (WVTR) or Moisture Vapor Transmission Rate (MVTR) is the rate at which water vapor will permeate through solid material over a specific period of time. Permeability: All polymers are permeable to gases and vapors to different extents.

Can water Vapour pass through plastic?

Water, as a vapour, can pass through some plastic packaging considerably more easily than expected. It is one of the most damaging contaminants, since in the vast majority of pharmaceutical products the water content has to be accurately maintained.

What is MVTR and OTR?

Two of the most important and widely used test method and standard used in food packaging industry used to establish barrier properties and thus shelf-life expectations this are the Oxygen Transmission Rate (OTR) and Moisture Vapor Transmission Rate (MVTR).

What is ASTM E96?

Water Vapor Transmission ASTM E96. Scope: The test evaluates the water vapor transfer through semi-permeable and permeable samples. The data can be used by manufacturers and designers and is often important in packaging applications.

What is WVTR and OTR test?

Oxygen and Water Vapour Permeability Oxygen transmission rate (OTR) and water vapor transmission rate (WVTR) are two key material specification properties which determine the shelf life of food packaging. Smithers offers a full range of barrier testing services, including an inter-laboratory proficiency scheme.

What is GTR packaging?

N500 Gas permeation tests the gas transmission rate (GTR) of packaging material,Is widely used in food industry, pharmaceutical industry, flexible packaging materials industry (plastic film, barrier materials, sheets, metal aluminum,PVC sheets), university and quality institution for gas(O2,CO2,N2,etc)permeation test …

How do you calculate water vapour permeability?

Water vapor transmission were measured and corrected by different calculation methods and because in this work the thickness of all films is known, the calculation of water vapor permeability is obtained by multiplying permeance by thickness.

Can I use polythene as a vapour barrier?

A vapour barrier can easily be realised with a plastic foil like Polythene (at least 0.2 mm thick). This can be attached with staples beneath the rafters or trusses on the inside.

What is ASTM E154?

ASTM-E154 › Standard Test Methods for Water Vapor Retarders Used in Contact with Earth Under Concrete Slabs, on Walls, or as Ground Cover.

What is ASTM E136?

Standard: ASTM E136 – Standard Test Method for Behavior of Materials in a Vertical Tube Furnace at 750°C. Certification Required: The International Building Code (IBC) and International Residential Code (IRC) prescribes this test for materials that are required to be non-combustible.

What is WVTR and OTR?

What is gas transmission rate?

Gas Transmission Rate (GTR): The quantity of a given gas passing through a unit of the parallel surfaces of a plastic film in unit time under the conditions of test. The SI unit of GTR is 1 mol / (m2·s).

What is a good water vapor permeability?

Unlike bulk water holdout, which refers to water in its liquid form, vapor permeability concerns water in its gas form. Current building codes require the minimum measure of permeability to be around 5 perms.

What is water vapour coefficient?

The µ-value represents the ratio of the diffusion coefficients of water vapor in air and in the building material and has therefore a simple interpretation: it is the factor by which the vapor diffusion in the material is impeded, as compared to diffusion in stagnant air.

What is the minimum thickness of a vapour barrier?

Vapor barrier thicknesses range from 6 mil to 20 mil, with 6 mil being the bare minimum and 20 mil being the most heavy duty and puncture-resistant.

Can you use 4 mil plastic for vapor barrier?

OVERVIEW. Our 4-mil plastic sheeting is a multipurpose film perfect for a wide variety of construction or DIY projects. This medium-duty plastic sheeting is commonly used as a vapor barrier in between insulation and drywall, used as a drop cloth or a temporary cover for equipment and supplies.

What is ASTM E108?

Scope: ASTM E108 is a fire-test-response standard that is used to evaluate roof coverings in both residential and commercial roofing applications for materials used on combustible or noncombustible decks. The evaluation simulates the fire originating outside the building accompanied by wind conditions.

What is ASTM e84?

The ASTM E-84 is the standard test method for assessing the surface burning characteristics of building products to explore how the material might contribute to flame spread in the event of a fire. The test reports the Flame Spread index and Smoke Developed index of the tested product.

What is WVTR (water vapor transmission rate)?

Definition: Water Vapor Transmission Rate (WVTR) or Moisture Vapor Transmission Rate (MVTR) is the rate at which water vapor will permeate through solid material over a specific period of time. Permeability: All polymers are permeable to gases and vapors to different extents.

What is water vapour rate in packaging?

Rate in Packaging: When referring to packaging, WVTR is the rate at which water vapors will permeate the package wall. Measurements: WVTR is measured in mg/Day per container.

What is moisture vapor transmission rate?

Moisture vapor transmission rate, also called water vapor transmission rate (WVTR), is the amount of water vapor that passes through a substance or material over a specific period of time. Why Is MVTR Important?

What is the best WVTR for polymer packaging films?

As shown in Table 9, gauge for gauge, OPP provides the best WVTR of all common polymer packaging films. (For homogeneous films like these, you can calculate the WVTR for a particular thickness by dividing the values in the table by the desired gauge in mils.)