Friction sensitivity tests method

Explosive Sampling, Inspection and Testing, Friction Sensitivity Test Method T 510.1, Department of Defense, USA. 

Marshall 2(1917) Falling Weight Test (Lenze) (p 423) Friction Sensitivity Test (423) Sensitiveness to Detonation (429) Sensitiveness to Heat (434) Ignition Temperature (434) Heat of Explosion (440) Trauzl Test (469) Strength by Ballistic Pendulum (473) Velocity of Detonation by Dautriche Method (479) Brisance Meter of Hess (495)... 

Suzuki, Kato, Fukuda et al. have conducted drop hammer sensitivity tests, friction sensitivity tests, and card gap tests on composite propellants that include nitramine 18 . The authors have conducted safety evaluations in cooperation with engineers from Nippon Oils and Fats Corporation to prove that no detonation propagation exist in composite propellants. We used new evaluating methods 11 131. The outline of our study follows. As new methods were constantly being adopted for the study, our tests were conducted on trial-and-error basis. All of the tests described here are not necessary for the evaluation of the detonating feature in composite propellants. 

Friction Sensitivity Test (Picatinny Arsenal, NJ), MIL-STE 650, Method T 510.1... 

The 60/40 mixt was cast-loaded to a density of 1.65 its mp 65-70°, Expln Temp 264° higher Brisance, by Copper Cylinder Crusher Test 100% (PA=100%) Power by Ballistic Mortar 96% (PA=100) Deton Velocity by Dautriche Method 7050m/sec Impact Sensitivity with 15kg Weight 14cm (max wt for no expins) Friction Sensitivity 60kg (max pressure betw two rubbing surfaces for no explns). Used, under the name Type 98, in Navy Bombs,... 

Testing methods ensuring uniform evaluation were developed accordingly. Some of them are included in the Railroad Traffic Regulations (- RID), since certain sensitivity limits are clearly specified by law for the transportation of explosives within individual countries, as well as for international traffic. For details -> Friction Sensitivity, -> Impact Sensitivity - Heat Sensitivity. 

Friction sensitivity is often reported as the force applied to the striker that is sufficient to initiate a reaction (in a specific percentage of trials). However, because of differences in test methods, it is not unusual to find a range of values reported for the same pyrotechnic material. 

One of the recommended test methods for the determination of friction sensitivity was also developed by the German BAM [38]. If the substance to be tested is a solid, drying and sieving is recommended. This increases the sample s sensitivity to an extent, diich most probably exceeds the same under process condition. For the test the sieve fiaction is used which has passed the 0,0005 m mesh. Approximately 10 mm are spread over 0,1 m on a specific part of a porcelain plate. A specially shaped porcelain peg, which is fixed to a loading arm, is once moved forward and back over the sample, thus exerting a mechanical stimulus. 

For initial safety testing, the impact and friction sensitivities were tested according to BAM methods [85,86] with the BAM Fallhammer and BAM friction tester . Compound 2 is very sensitive towards impact (< 1.5 J) and... 

Some other results of KDNP investigations were summarized by Fronabarger et al. [49]. The report unfortunately does not specify the crystal form of the material. Nevertheless, the reported properties are as follows impact sensitivity by ball drop method—51 22 mJ, friction sensitivity by BAM 175 g (no-fire level) 200 g (low fire level), thermal properties by DSC at 20 °C min —small endo at 145 °C, decomposition onset 278 °C, solubility in water—moderately soluble at normal temperature. Reactivity with aluminum, stainless steel, brass, and cadmium was not observed. Output measured as an impetus is reported better than LS in a closed bomb test. 

The sensitivity of an energetic material towards accidental stimuli such as fast heating, electrostatic discharge, friction, impact and shock determines its safety characteristic and, hence, decides whether a certain material may be actually used and whether it can be safely transported. Corresponding test methods are described in Test Series 3 of the UN Orange Book [la]. These tests determine the sensitiveness to impact, friction (and impacted friction), thermal stabiUty and response of the substance to fire. 

For measuring and testing the friction sensitivity, samples of energetic compounds are exposed to friction forces that are generated by different setups and methods. " In the ABL (Allegheny Ballistics Laboratory) Sliding Friction Test the sample is pressed by a steel roll with an adjustable force on an anvil which is accelerated by the impact of a... 

Determination of Detonation Velocity (71-4) Sensitivity to Impact (Sensibilite/ au choc) (74-5) Sensitivity to Friction (75-6) Sensitivity to Initiation (Sensibilite a 1 amorce) (76) Pressure Measurements by Manometric Bomb, by Crusher Test and by Piezoelectric Manometer (79 97) Density Determination (99-100) Chronographs of Schulze and of Le Boulange (101) Tests for Stability by Methods of Abel, Spica, Vieille at 110°C, German at 135° Bergmann-Junk, Su, Hansen-Grotannelli, Silvered Vessel and Taliani (107-09) Explosion Test (109-10)... 

The coefficient of linear expansion can be measured as an average over tens of °C to reasonable precision using a precision cathetometer. Most contact methods of measuring length are not suitable because of the low stiffness of rubber and, for the same reason, it is often necessary to support the test piece in a horizontal position. A convenient procedure is to lay a test piece on smooth rollers in a glass-sided bath, but it must be emphasised that only moderate precision can normally be obtained, unless an extremely sensitive optical measuring device is employed, and friction can never be eliminated. 

Previously reported [2] as a non-melting solid exploding on attempted purification, this proved a very shock sensitive (40 kg/cm) solid of m.p. 150°C. Less sensitive to electrostatic discharge and friction. Methods of explosibility testing for very small quantities of very sensitive materials are described [1]. 

Certain laboratory tests (tress combing, fiber friction, fight scattering, sebum removing ability, etc.) can be more sensitive than consumer s evaluations (see the section in this chapter entitled Methods to Evaluate Clean Hair ). However, the most severe constraint with laboratory testing is that laboratory measurements are often only a portion of the related consumer assessment. For example, fiber friction is only a small part of how the hair feels to a consumer or how easily her hair combs, and hair combing is only a portion of hair conditioning. 

The friction test is used to determine an explosive s sensitivity to friction, which is of considerable interest during manufacturii. One method of conducting this test is to use a pendulum and anvil. The explosive is spread out on the anvil, and a specially designed weight (shoe) attached to a pendulum arm is allowed to swing back and forth across the anvil. Sensitivity to friction is measured by the number of snaps, cracks, ignitions, or explosions resulting from the interaction of the pendu-liuu shoe and the explosive. 

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