Significance and Use

The purpose of this test method is to obtain reliable values for the WVTR of plastic film and sheeting.

WVTR is an important property of packaging materials and can be directly related to shelf life and packaged product stability.

Data from this test method is suitable as a referee method of testing, provided that the purchaser and seller have agreed on sampling procedures, standardization procedures, test conditions, and acceptance criteria.

1. Scope

1.1 This test method covers a procedure for determining the rate of water vapor transmission through flexible barrier materials. The method is applicable to sheets and films up to 3 mm (0.1 in.) in thickness, consisting of single or multilayer synthetic or natural polymers and foils, including coated materials. It provides for the determination of ( 1 ) water vapor transmission rate (WVTR), ( 2 ) the permeance of the film to water vapor, and ( 3 ) for homogeneous materials, water vapor permeability coefficient.

Note 1Values for water vapor permeance and water vapor permeability must be used with caution. The inverse relationship of WVTR to thickness and the direct relationship of WVTR to the partial pressure differential of water vapor may not always apply.

1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASTM Standards

D374 Test Methods for Thickness of Solid Electrical Insulation

D1898 Practice for Sampling of Plastics

E96/E96M Test Methods for Water Vapor Transmission of Materials

E104 Practice for Maintaining Constant Relative Humidity by Means of Aqueous Solutions

E178 Practice for Dealing With Outlying Observations

E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method

Keywords

Flexible barrier materials; Diffusion cell apparatus; Infrared (IR) analysis--plastics; Plastic sheet and film; Polymers; Referee methods; Water vapor transmission (WVT);

ICS Code

ICS Number Code 83.140.10 (Films and sheets)

DOI: 10.1520/F1249-06R11

ASTM International is a member of CrossRef.

ASTM F1249