Powders, test methods

Tartaric acid is suppHed as Fine-Granular and Powder in 45-kg bags. It should be stored in tightly closed containers. Test methods for tartaric acid and some tartrates have been described (40,87). 

Bemrose, C.R. and Bridgwater, J., 1987. A Review of Attrition and Attrition Test Methods. Powder Technology, 49, 97-126. 

In a 30 minute test the results obtained should not differ by more than 1 minute using different lots of paper. On being exposed to nitric oxide fumes, these papers slowly turn green, followed by a salmon pink coloration Methyl Violet Paper Test (Field Test for Pro pint Powders). This method of testing proplnts using 0.1N methyl violet paper directly in the containers in which the powder is stored, was developed at Picatinny Arsenal in 1928—29 (Refs 1 2), and was adopted by the Ordnance Dept to replace the Observation Test about 1931... 

Fig 14 Comparison Between Three Test Methods for Particle Size Distribution of H-15 A1 Powder... 

In friability tests the material s susceptibility to attrition is evaluated. But it is not as simple as it may seem at first to select the suitable test procedure. In this context Pell (1990) gave a simple thought experiment to illustrate the difficulties If we took a batch of rubber stoppers and a batch of diamonds, and rubbed them on abrasive paper, we would conclude that the diamonds were more attrition resistant. If we instead struck the particles with a hammer we would conclude that the rubber were more attrition resistant. So, different test methods can rank materials differently with respect to their attritability. This effect was for example observed by Knight and Bridgwater (1985). They subjected spray-dried powders to a compression test, a shear test and a test in a spiral classifier. They found that each test gave a different ranking of the materials. Obviously, there is no... 

Other test methods are the powder bulk, aerated, and layer tests [137,138]. Several systems in-house built are available. All of these tests operate on the principle that a layer of the substance under investigation is heated in a circulating air oven as the temperature is increased. Air is transported through the sample (in the aerated test, the air flow is downward through the sample), and the temperature of the powder at several places is recorded. 

Polyester polyols, 25 464 468 Polyester resin(s), 11 302 coating resins, 7 104-106 cyclopentadiene and dicyclopentadiene applications, 8 230 flammability of, 20 115-116 properties in powder coating, 7 43t standard test methods for, 20 11 It unreinforced, 10 187t weathering of, 20 116 Polyester resin-based powder coatings, organic titanium compounds in, 25 125 Polyester resin composites, 26 762-763 Polyester resin formulations ingredients of, 20 96t unsaturated, 15 511-512 Polyesters, 10 185-189, 497 12 655-656. See also Thermoplastic polyesters Unsaturated polyesters acid resistance of, 20 7-8 antioxidant applications, 3 121 aromatic ionic, 23 722 based on 1,4-cyclohexanedimethanol, 12 674-675... 

The test methods discussed in this context are broad in scope and relate to a variety of applications. In some such tests, a pigment powder is extracted with water and its contents analyzed other procedures reveal the stability of a pigmented system with regard to water, acids, or bases. A number of these tests have developed into industrial standards. 

Bemrose, C. R. and Bridgwater, J. Powder Technology 49 (1987) 97. A review of attrition and attrition test methods. 

Solvent absorption measurement has been shown to be a sensitive and useful test method in the manufacture of epoxy powder coatings. A test method was defined and the effects of time and temperature of immersion described. It was shown that solvent absorption is a measure of raw material properties (EEW of the epoxy resin, and CTBN elastomer type and concentration), the homogeneity of the extrudate, as well as the state of cure. The information obtained from solvent absorption measurements has proven to be extremely important not only in quality control analysis but also in providing an insight into the structure function relationships in epoxy resin chemistry. 

In addition to the testing methods common to nitric esters (nitrocellulose, nitroglycerine) and smokeless powder there are also methods used exclusively for testing the stability of smokeless powders. 

ASTM D731, Test Method for Molchnglndex of Thermosetting Molding Powder, Vol. 8.01, ASTM, Philadelphia, Pa., 1993. 

Metz(Ref 3) compared Brunswig s Test method with other quantitative stability tests(such as Mayrhofer, Mayrhofer-Will, Hansen and the 85° 110° Hydrolysis Tests) and with qualitative tests(such as Abel the 134.5° Heat Tests). Brunswig s method is indicated to be applicable only to extremely stable powders. For example, if a powd is of moderate stability and just passes other quantitative tests, it might not pass Brunswig s Test. On the other hand, if a powd passes Btunswig s Test it usually passes other quantitative tests but may not pass qualitative tests, such as Abel s, Zinc-Iodide-Starch Test others... 

Trivilene. One of the names for Dirutrotoluene, when used for coating cannon powder grains Ref Anon, Smokeless Powder Cannon Ingredients , Hercules Powder Co Test Method S-50 (Feb 27,1936 revised Oct 1,1940)... 

Many other organic and some organometallic materials have been examined by the powder SHG method and/or tested by EFISH techniques. They will not be discussed in detail here but are listed by structural classes for completeness. Several compendia of materials responses have been published. (38,54,55) Clearly, the largest single class of second order materials consists of donor-acceptor substituted aromatics. The class has been extended to stilbenes and diarylacetylenes and... 

The presence of a powder as an aerosolized mist may be used so that testing will be by an electronic eye. Manual methods include listening devices for sound inspection or sprays for visual inspection of sprays. Hoods or spray booths are used online where inspectors manually actuate units and observe for defective sprays. Manual actuation for sound may be performed into vacuum setups with microphones that amplify the valve actuation noise. The usual number of actuations for testing is between three and five. At least two are considered as priming shots, followed by a test fire. Rejection rates vary from lot to lot and supplier to supplier but are usually less than 0.1%. The rejection rate, classified by defect, and the testing method should be documented for the validation lots. Rejected units should be closely examined for any false results and may be used to improve the valve manufacturer s quality control. 

Kohler et al. discussed the potential of the chemiluminescence technique as an industrial test method. Imaging chemiluminescence was used to assess antioxidant performance. An advantage over oven aging was found to be the possibility for evaluation of the oxidative stability of samples with unusual geometries, such as fibres and powder particles [136]. A correlation was also found between oven aging and chemiluminescence measurements on stabilised PP and it was shown that chemiluminescence measurements done at... 

Svarovsky, L. (1987), Powder Testing Guide, Methods of Measuring the Physical Properties of Bulk Powders, Published on behalf of the British Materials Handing Board by Elsevier Applied Science, London, pp. 3-33, 79-95. 

Solid-state methods Kurtz powder test... 

NF 11 -661 Test methods for particle size analysis-Determination of particle size of powders-Optical microscope, 144... 

ASTM C285-88 (Re-approved 1994) Standard test method for sieve analysis of wet milled and dry milled porcelain enamel, for determination of the fineness of frit in wet-or dry-milled porcelain enamels and other ceramic coatings on metals by use of the number 200 or No 325 mesh, 212 ASTM C925-79 (Re-approved 1995) Standard test method for precision electroformed wet sieve analysis of non-plastic ceramic powders, for particle size distribution determination ofpulverized alumina and quartz for particle sizes from 45 pm to 5 pm by wet sieving, 212, 230... 

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