Standard Test Method for Quantitative Exudation Measurement of Flexible Poly(Vinyl Chloride) Plastics

Importancia y uso:

5.1 It is possible for plasticizers and other formulation ingredients to migrate and accumulate on the surface of a PVC resin fused compound. This phenomenon is commonly described as exudation or blooming. The exudation can be measured by weighing the flexible PVC sample before and after cleaning the surface, where the weight difference indicates the weight of the exudate that had accumulated on the surface after a certain period of time and was removed by the cleaning procedure. This test method does not evaluate mass loss over time, as the mass of the sample at the beginning of the experiment is not relevant. This test method measures the amount of exudate accumulated on the surface of the PVC compound, measured every time unit (that is, week), over a period of time (that is, eight weeks) to generate a curve of exudate accumulation over time.

5.1.1 This test subjects a standard test specimen to a chosen set of conditions and allows quantitative determination of the amount of exudate that accumulates over a period of time.

5.1.2 This test is applicable only for comparison purposes between different PVC formulations, with equal conditions during the length of the experiment.

5.1.3 An apparent decrease in compatibility of plasticizers or other components with subsequent exudation can cause excessive dirt pickup, marring of lacquered or varnished surfaces, sticky or oily feel, and a number of other associated problems.

5.1.4 When a plasticized PVC sheet is observed over a period of time, the migration of some components might be observed. A test of two week's duration is used for screening of high exudation materials, while an extended test of eight to sixteen weeks duration is used for a complete profile.

Note 1: It is permissible for the seller and the purchaser to agree upon test conditions of time, temperature, or relative humidity.

Subcomité:

D20.15

Volúmen:

08.03

Palabras clave:

additives; exudation; plasticizer compatibility; plasticizers; poly(vinyl chloride);