Radial tensile strength

Nystrom, C., K. Malmquist, J. Mazur, W. Alex, and A. W. Holzer. 1978. Measurement of axial and radial tensile strength of tablets and their relation to capping. Acta Pharm. Suec. 15 226-232. 

B. Igne, C. A. Anderson, and J. K. Drennen, Radial Tensile Strength Prediction of Relaxing and Relaxed Compacts by Near-Infrared Chemical Imaging, Int.. Pharm., 418,297 (2011). 

The tensile strength of tablets is routinely tested as a measure of tablet quality [2]. It is possible to consider three types of tensile strength - radial, bending, and axial. Here we discuss only the radial tensile strength as it is... 

The radial tensile strength is assessed by measuring the diametrical crushing force using what is commonly referred to as a hardness tester . The diametrical crushing force is dissimilar to indention hardness and the use of hardness in the present context is erroneous but nonetheless conventional. Like other mechanical tests, the diametrical crushing force is dependent on the test speed thus, results may vary between testers. 

The radial tensile strength, t, is calculated from the diametrical crushing force, f, for cylindrical tablets using the relation below [2-4]. 

Here, d is the tablet diameter and h the tablet thickness. It is the radial tensile strength that is commonly determined to assess tablet quality. Procipio et al. [5] have discussed measurement of radial tensile strength. 

In an earlier paper, Wu et al. [20] proposed a model to calculate the radial tensile strength of tablets from the Ryshkewitch-Duckworth parameters of... 

In this paper the compaction of several common pharmaceutical excipients blended with sodium dodecyl sulfate is investigated. Furthermore, a model based on the principles of adhesion science is proposed for calculation of tablet radial tensile strength as a function of tablet porosity for powders composed of several materials. The data indicate that the model, indeed, allows for the calculation of tablet tensile strength from the Ryshkewitch-Duckworth parameters of the component materials. 

FIGURE 31.13 (a) Plot showing the stress-strain behavior of various irradiated rubbers, (b) Plot showing the variation of tensile strength and modulus of rubbers irradiated with different doses, (c) Plot showing the variation of hysteresis loss, set, and elongation at break of irradiated fluorocarbon rubbers. (From Banik, I. and Bhowmick, A.K., Radial. Phys. Chem., 54, 135, 1999. With permission.)... 

Radial wire is the mat of steel placed under the tread to enhance tread strength and durability. Bead wire consists of many strands of high tensile strength steel that provide strength and reinforcement to the tire side walls. Radial and bead wires can account for as much as 10 percent of the total weight of a tire.3 The remainder of the weight of the tire is about 60 percent rubber, and 30 percent fiber. 

Rope represents a very useful form of fibrous product. A rope or cord consists of a bundle of fibers. The fibers may be continuous or they may be made of staple fibers, i.e. short, fine fibers. The tensile strength of a rope comes from the strength of individual fibers and the friction between them. The interliber friction prevents their slip past one another. Quite obviously, a rope or a cord has very anisotropic properties. It is strong in tension along the axis direction but not in the transverse or radial direction. Strength in compression is also very poor. 

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