Standard Test Methods for Water Absorption of Plastics

ASTM D 570, Standard Test Methods for Water Absorption of Plastics  

The ASTM procedure covers the determination of the relative rate of absorption of water by plastic when immersed. Ideally, diffusion of water (or liquid in general) into plastics for long-time immersion procedure follows the square root of immersion time, with the initial slope of the graph proportional to the diffusion constant of water in the plastic. The plateau region with little or no change in weight represents the saturation water content of the plastic. The ASTM recommends that the saturation level is reached when the increase in weight per 2-week 

WATER ABSORPTION BY COMPOSITE MATERIALS AND RELATED EEEECTS 

The ASTM notices that the rate of water absorption may be widely different through each edge and surface. It may be greater through cut edges than through molded surface. Hence, quantitative correlation of water absorption with the surface area should be limited to similarly shaped specimens and to closely related materials. Also, for materials with widely varied density, relation between water-absorption values on a volume as well as weight basis may need to be considered. 

The ASTM procedure specifies in detail the dimensions of specimens for molded plastics (in the form of a disk), plastics (in the form of a square), sheets, rods, and tubes. For example, the test specimen for molded plastics shall be in the form of a disk 2 in. in diameter and 1/8 in. in thickness. Specimens should be preferably dried for24hat50°C. (122°F). 

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ASTM D 570-81 (1988) Standard Test Method for Water Absorption of Plastics, 3 pp (DOD Adopted) (FSC 9330) (MR) (Comm D-20)... 

ASTM D570 Standard Test Method for Water Absorption of Plastics. Used to determine the relative rate of absorption of water by plastics when immersed. D570 is applieable to the testing of all types of plastics, including cast, hot-molded, and cold-molded resinous products, and both homogeneous and laminated plastics in rod and tube form and in sheets 0.13 mm (0.005 in.) or greater in thickness. ISO 62 is technically equivalent to this test method. 

Standard Test Method for Rubber Property - Vapour Transmission of Volatile Liquids Standard Test Method for Water Absorption of Plastics Standard Test Methods for Water Vapor Transmission of Materials... 

The cured matrices were dried in an oven at 110°C for one horn. Immediately upon cooling, the specimens were weighed. The specimens were immersed in distilled water at ambient temperature and weighed at predetermined times. Every procedme was performed by following ASTM D570-98 Standard test methods for water absorption of plastics [30]. The specimen size was 1.2 cm x 7.5 cm x 0. 3 cm and the water gain percentage, M%, was determined from the equation ... 

When water is used as the immersion liquid, the test is essentially the ASTM Standard Test Method (D570) for Water Absorption of Plastics.( ) Determinations of the relative rate of water absorption are important in evaluating the effects of moisture exposure on such properties as mechanical strength, electrical resistivity, dielectric... 

The standard test for assessing water absorption of plastics is given in ISO 62 [210]. w hich defines four methods of test. It is applicable to a wide range of plastics in various forms but is not suitable for cellular plastics. 

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