Table of Contents
What is ASTM E96 procedure A?
ASTM E96 Water Vapor Transmission Rate Test Methods In the Desiccant Method, the test specimen is sealed to a test dish containing a desiccant, and the assembly is placed in a controlled atmosphere. Periodic weighings are used to assess rate of water vapor movement through the specimen into the desiccant.
What is desiccant method?
The desiccant method assembly measures weight gain due to water vapor from the chamber transmitting through the material due to the desiccant absorbing any moisture from the material sample and the humidity from the test chamber that is being absorbed by the material.
What is ASTM e96 method B?
ASTM E 96 Method A or Method B maintains a steady vapor pressure difference by creating a stable environment within the metal cup, and placing the metal cup in a controlled temperature/humidity chamber. The chamber is typically held at 23.0°C/ 50% RH.
What is the 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 are the various methods of determination of WVTR of packaging materials?
The two common and standardized methods for measuring WVTR are ASTM E96, and ASTM F1249.
Which chemical is used in desiccator?
Constituents. The lower compartment of the desiccator contains lumps of silica gel, freshly calcined quicklime, Drierite or (not as effective) anhydrous calcium chloride to absorb water vapor. The substance needing desiccation is put in the upper compartment, usually on a glazed, perforated ceramic plate.
What is Class A material?
Class A rated materials are the only materials that can be specified on external applications and specified attachments on buildings higher than 18 meters. Only materials that are rated A1 or A2 are considered non-combustible materials according to the European Classification (Euroclass) System.
What is WVTR in food industry?
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.
What is ASTM E 96 / E 96m?
The ASTM E 96 /E 96M. Water Vapor Transmission Rate test methods cover the determination of water vapor transmission (WVT) of materials through which the passage of water vapor may be of importance, such as paper, plastic films, other sheet materials, fiberboards, gypsum and plaster products, wood products, and plastics.
What are the two basic methods covered by ASTM e96-22?
The two basic methods covered in ASTM E96-22 are the Desiccant Method and the Water Method.
What are standard test conditions for selection in astme 96?
The appendix of ASTME 96 has listed several groups of standard test conditions for selection. When the specimen area is larger than the mouth area, this overlay upon the ledge is a source of error, particularly for thick specimens. The overlay material results in a positive error, indicating excessive water vapor transmission.
When to use a dummy specimen for water vapor transmission studies?
When results of water vapor transmission are expected to be less than 0.05 perm, a dummy specimen is strongly recommended. Such a dummy specimen should be attached to an empty cup in the normal manner.