Drop Weight Properties

Accordingly, it was deemed a substance too dangerous to be produced in an ordinary chemical plant. On the other hand, it was also found that its dangerous properties were not easily identified by some commonly practiced test methods an ordinary differential thermal analysis did not give a result suggestive of the danger, and a drop weight sensitivity test of solid 5-CT indicated that the substance was insensitive to percussion. 

Numerous studies have been made of the mechanical properties of fibrous composites these include recently published papers on impact properties by Izod (1,2, 3,4) and Charpy (5,6) and drop weight (7) tests. We reported the Charpy impact fracture behavior of various glass-polyester composites regarding the effects of temperature (8,9,10), specimen size (8), and fiber orientation (10). This paper describes the effects of the tough-brittle transition in the impact behavior of glass-polyester composites which occurs with a variation of temperature and specimen size. 

For conditions of constant craze thickening rate, agreement between prediction and experiment is already very encouraging, particularly at higher speeds. There are still refinements to be made to the experimental method, and drop-weight striker speeds of less than 0.5 m/s will remain inherently difficult to control. Nevertheless, the Full Notch Impact test provides a promising direct method for the measurement of cohesive properties in tough polymers. 

Commercial ABS/PA-6 blend exhibits excellent notched Izod impact (> 850 J/m) at room temperature and good drop weight impact (> 40 J) at -40°C. These impact properties are equivalent to the impact modified polyamide (Table 15.20). However, the DTUL (0.45 MPa) of ABS/PA blends are relatively low compared to those of impact modified nylons. The key difference being that in ABS/polyamide blends, due to the significant level of ABS, a substantial drop in the modulus occurs... 

Solomon S, Abu Bakar A, Ishak Z A, Leong Y W, Ishiaku U S and Hamada H (2007) Drop weight impact properties of (CO) injection molded short glass fiber/short carbon fiber/polyamide 6 hybrid composites, J Reinf Plast Comps 26 405-418. 

Stearic acid reacts to form stearate as shown above, and such coatings can also be applied as stearate salts. The use of salts has been shown to have favourable effects on compound properties. For example, when magnesium stearate is used as an alternative to stearic acid for coating magnesium hydroxide, tensile and impact properties (measured using an instrumented drop weight impact tester) are both improved as shown in Table 1. 

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