ASTM Recommendations

ASTM D 790, Standard Test Methods for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials  

Note of the author This procedure was one of the most widely used of the mechanical property tests for wood-plastic composite (WPC) materials, as the specimen geometry is very simple as well as the testing equipment. However, it became more and more obvious that material properties, tested by this method, were not necessarily corresponding to the product properties, such as composite deck board. 

Composite products are often not precisely uniform in their composition sometimes they contain voids, their surface (particularly unbrushed) often contains more plastic compared to the bulk material, and so on. To make data obtained more realistic, ASTM D 6109 was developed (see below). 

The ASTM procedure describes procedures for determining flexural properties of materials in the form of rectangular bars. The ASTM emphasizes that it is applicable to only those materials that break or fail in the outer surface within the 5% strain limit at midspan. The method employs a 3-pt loading system (concentrated load) applied at midspan of a simply supported beam (Fig. 7.4). 

Note of the author The maximum strain in the outer surface at concentrated load is equal to 

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Temper. The system for designating material condition, whether the product form is strip, rod, or wine, is defined in ASTM Recommended Practice B601 (1). The ASTM system uses an alpha-numeric code for each of the standard temper designations. This system replaces the historical terminology of half hard, hard, spring, etc. Table 3 summarizes temper designations. 

In addition to the nomenclature based on ISO and ASTM recommendations several other abbreviations are widely used. Those most likely to be encountered are shown in Table 4. 

The American Society for Testing Materials (ASTM) recommends 250 ml of solution for every square inch of area of test metal. Exposure time is also critical. Often it is desirable to extrapolate results from short time tests to long service periods. Typically, corrosion is more intense in its early stages (before protective coatings of corrosion products build up). Results obtained from short-term tests tend to overestimate corrosion rates which often results in an overly conservative design. 

Figure 19.8 shows the design of an all-glass cell, which has been listed as the standard polarisation cell in the ASTM Recommended Practice G5 1987, which makes provision for the essential requirements listed above this cell is typical of those used for fundamental studies and for testing, although details of design may vary. 

The difficulties associated with the ASTM Recommended Methods for Detecting Susceptibility to Intergranular Attack in Austenitic Stainless... 

An ASTM recommended practice (A Standard Reference Method for Making Potentiostatic and Potentiodynamic Anodic Polarisation Measurements, G5 1972) has been issued. It provides a means of checking experimental technique and instrumentation using a specimen from a single heat of AISI Type 430 stainless steel, which is available from ASTM. ... 

American Society for Testing and Materials (ASTM), Recommended Practice for Analyses by Microscopical Methods, ASTM Part 23 and 30, Philadelphia, Pa., 1973. 

The properties of the fuel oil blend met the requirements for ASTM No. 4 fuel oil (usually considered a distillate fuel) except that its viscosity was low, falling between the specified requirements for No. 2 and No. 4 fuel oils (7 ), and its pour point of 30° F was higher than the ASTM-recommended maximum of 20° F. The fuel could be used as a low-sulfur, high-cetane-index grade 4-D diesel fuel in warm weather or where preheating facilities were available. 

The volumetric marks on volumetric ware are called calibrations. How they were located on the volumetric ware is called calibration. All volumetric ware is calibrated to provide its stated volume at 20°C. The International Standards Organization has recommended that the standard volumetric temperature should be changed to 27 °C. However, so far there has not been any significant movement toward this goal. The ASTM recommends that those labs in temperate climates that are unable to maintain an environment at 20°C should maintain one at 27°C. 

Biodegradation. The ASTM recommended procedure was used for the fungal degradation experiments (2j. The enzymatic degradation procedure developed in our laboratory has been described recently (3). 

Computer terminals are installed in many individual booth areas. The ASTM recommended booth bench size of 30 inches (76cm) wide, and 15 inches deep, may not be sufficient to house the terminal as well as the sample. The terminal may also introduce distracting colour and contrast into the booth via the fiitish and screen colours. Any contrast introduced may be particularly intmsive during translucency assessments, or colour assessments of translucent samples. Therefore, the colour of the terminal and its orgaitisation into the booth should be considered with care. Translucency becomes evident either when... 

X 1.0" (cylinder) in size. Though, for different types of compressive behavior, the ASTM recommends different sizes of the specimens. 

Most of the ASTM recommendations applicable for WPCs have been developed either for plastics (ASTM Committee D20) or for wood (ASTM Committee D7). ASTM procedures developed specifically for WPCs have started to appear only lately. This situation is applicable for majority of WPC properties—slip, flammability, microbial degradation, oxidative degradation, among others, but test methods for some of them are essentially the same, regardless of wood or plastic for some they are quite different. Recommended test methods for water absorption are quite different for wood or plastics. The principal ASTM procedures for both of them are given below. 

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... 

ASTM RECOMMENDATIONS ASTM Tests for Oxidative Induction Time... 

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