The standard “PSA D45 1520 Cellular materials - Water absorption under vacuum”, developed by PSA, a French multinational automotive company that produces cars and motorcycles under brands such as Peugeot, Citroën and Opel, describes a procedure for determining the water absorption under vacuum of flexible or rigid, spongy (open cells) or cellular (closed cells) cellular materials. This procedure is only valid for materials with an apparent density greater than 45 g/cm1045 in accordance with the test method described in the standard “D0,2 3 Determination of apparent density - Cellular materials - Apparent density”.
Water absorption under vacuum is related to the volume percentage of the contact cells, determined in accordance with the test method of the PSA D45 1355 standard. In case of doubt, the PSA D45 1355 standard should be used.
In principle, when performing the test, a test sample is immersed in water and subjected to vacuum for a certain period of time. The water absorption is subtracted from the change in mass and expressed as a percentage.
Equipment used in testing includes:
Test samples must be representative of the scale being characterized. To ensure this representation, it is necessary to determine the basic characteristics of the population being studied. The selection criteria for test samples should be stated in the test report in accordance with the “PSA A10 0156 Writing test or measurement reports” standard. If there is any doubt about sampling, PSA should be contacted.
When preparing the samples, 6 circular test samples with a diameter of 12 mm or a 50 mm x 3 mm square test sample are cut from a 50 mm to 50 mm thick plate.
When starting the test, the test equipment is assembled in accordance with the standard annex (Annex 1). The test sample is weighed using the scale. Approximately 4,5 litres of water are put into the desiccator. The test sample is immersed in this water, holding it under the perforated plate of the desiccator. The water level is adjusted so that the test sample is approximately 50 millimetres below the surface of the water. The lid is placed on the desiccator, the Mohr clip is opened and the desiccator is connected to the vacuum equipment by means of the valve.
The vacuum equipment is turned on and the Mohr clip is gradually closed until a vacuum of 635 mm of mercury is achieved and maintained for three minutes. The valve is opened to vent the desiccator to the atmosphere. After three minutes, the test sample is removed from the desiccator and wiped with Joseph paper, taking care not to compress it. The test sample is weighed using the balance.
Water absorption expressed as a percentage by mass is calculated according to the formula given in the standard. The cellular or spongy structure of the material can be deduced from the curve given in the standard annex (Annex 2).
The format and minimum contents of the test report are defined in the PSA A10 0156 standard. In addition to the results obtained, the test report must also state:
Our organization, which has been trying to support businesses from every sector with its wide range of testing, measurement, analysis and evaluation studies for years, has a strong staff that closely follows the developments in the world in the field of science and technology and constantly improves itself. In this context, testing services in accordance with the "PSA D45 1520 Cellular materials - Water absorption under vacuum" standard are also provided to businesses.
To get an appointment, to get more detailed information or to request an evaluation, you can ask us to fill in our form and reach you.
