DIN Determination of the water vapour transmission rate of plastic film, rubber sheeting, paper, board and other sheet materials by gravimetry. DIN Testing of plastics and elastomer films, paper, board and other sheet materials – Determination of water vapour transmission. DIN ENG_机械/仪表_工程科技_专业资料。Determination of the water vapour transmission rate of plastic film, rubber sheeting.
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The concentration is determined and the permeation rate is calculated. The water that has permeated through the sample is carried to the detector by a second carrier gas. You find this article here as a PDF.
This, however, is generally unnecessary in the case of non-hygroscopic film or sheets or of those having low water vapour transmission rates. They shall not exhibit any surface inhomogeneities e.
Use atmosphere B for rubber sheets, atmosphere D for plastic film and laminated paper, and atmospheres D and E for paper and board. In case of doubt, the German-language original should be consulted as the authoritative text.
In blank tests, examine samples having low permeation rate and large thickness e. Evaporation chamber, with a controlled atmosphere i. Make such blank samples in the same way and subject them to the same conditions, but without desiccant in the dishes.
Sealant, consisting of a wax mixture that adheres strongly to both the dish and the sample, is not brittle at the measuring temperature and is neither hygroscopic nor susceptible to oxidation. All dimensions are in millimetres. The internal depth of the dish dun be between 8 mm and 24 mm, but shall preferably be 15 mm.
DIN Standard – Testing Instruments – Labthink
For non flat specimens: This equation applies if the interval between consecutive weighings is 24 hours see subclause 8.
See DIN for other methods of determining water vapour transmission rates e. Details of any treatment of samples to remove the residual solvent shall be included in the test report. Testing method aplicable to nearly all materials, e. Take the arithmetic mean of the individual values and report 531222 to three significant places, but not to more than one decimal place. One chamber is filled with the test gas until test pressure is reached.
If both surfaces of the sample are to be measured, twice the number of samples shall be prepared. Cookies make it easier for us to provide you with our services. If the two surfaces of the sample are not the same, the test area, i.
Water or water vapour. Balance, capable of weighing to an accuracy of 0,1 mg. The same phenomenon will be observed if the humidity of the test atmosphere varies considerably during weighing. Use one of the following atmospheres in the evaporation chamber: For undated references, the latest edition of the publication referred to applies.
Home Test Lab Permeation What about permeation? Since the water vapour transmission rate depends on xin that include the thickness and matrix of the sample material, it is not a material constant. We recommend the measurement of three independent samples per test minimum number not regulated by the standard.
Two points are important in selecting the size of dish, namely preventing the desiccant from becoming saturated during the test, on the one hand, and dij the total mass, 531222 the other, to reduce its effect on the accuracy of weighing. The permeation gas displaces liquid out of a U-tube which is xin with the other chamber.
The total water absorption of the agent shall not exceed 1,5 g per 25 cm3 during measurement.
Water vapor permeability (electrolysis method) DIN / DIN A
It may also be due to sample defects and to differences in water vapour transmission rates in the case of samples with single-side dib even double-side lamination. Also possible are temperature profiles nonisothermic measurements for the determination of morphology changes and the influence of media and pressure on polymer properties. Details of sealing samples 8 8. If you want to conduct the cutting of the specimens yourself, please contact us for the required dimensions.
Water vapor permeability WVTR (electrolysis method) according to DIN 53122-2 / DIN 53122-2-A
It is advantageous to use a light metal lid that covers the dish when it is removed from the test atmosphere and weighed so that the sample releases as little water as possible to the surrounding air during weighing.
Continued on pages 2 to 7. It is advantageous to use material with a particle size of 1,5 mm to 2 mm that passes through a 4 mm sieve, has been freed of any fines using a 1,6 mm sieve, and has been dried in the normal manner. We also do the test sample manufacture for you. Then cover the dishes with the samples and firmly seal them to the dish wall, ensuring that the temperature of the sealant and any annular template used does not bring about any alteration in the sample.
In the case of highly transmissive samples, the number of dishes in the evaporation chamber may be kept low to ensure a constant and uniform distribution of humidity within the tolerances for the test atmosphere concerned see subclause 8.
A tempered test chamber is flushed by a carrier gas with a defined humidity. The standard does not define the sample size or thickness, a measuring area of at least cm 2 is proposed. Subtract the blank values from the values measured for the sample dishes having undergone the same treatment.
If the wax is spread out on the rims with the aid of a hot spatula, check that the seal is still intact after the sealant has cooled. For other time intervals: Furthermore interactions between media and polymer can be investigated. The test sample is mounted in a permeation cell so as to form the barrier between two chambers. Evaporation chamber without dishes shown in figure 2 or 3 NOTE 2: If these conditions are fulfilled, the water vapour transmission rate, WVTR, of similar samples of different thickness is inversely proportional to the thickness, i.
Cover templates of the type shown in figure 4 facilitate the sealing operation. A desiccator as shown in figure 1, for example, in a controlled-temperature or air-conditioned room may be used as evaporation chamber. After reaching the desired temperature, the measurement is started.