Quality control tests hardness

Thus prototype evaluation was performed using a variety of standardized tests, including various objective and subjective measures. Many of these laboratory tests were already being used to assess attributes of other products, either as quality control tests for ordinary soap bars or else in the development of detergent-based household products like laundry detergents or hard-surface cleansers. 

Disintegration time and tablet hardness data could be collected from the manufacturing batch records however, for ease of administration these figures will be obtained from the quality control test results, which also contain individual tablet weighings. 

There is a trend in commercial testing of product quality to introduce non-destructive methods, in other words, tests that leave no defects in the tested materials that would affect their working properties. The use of these methods not only spares products but also permits more frequent testing, and gives better product quality control. This should be considered in the choice of hardness determination method. 

The ATW, hardness, and disintegration time are determined by the press operator during compression. As in the case of drug A, we will not rely on these results for our study, but rather on the test data from quality control. 

The Izod impact strength values are useful in giving a rough ranking of materials for quality control purposes, since the tests are simple and quick to carry out. The test is hardly of any use for design calculations for plastic parts. Neither has the test any physical base. 

The quality of the product is defined in terms of the d.e., pH, buffer capacity, and content of dry substance, and of certain special specifications related to specific uses. An example of such a specification is the degree of inversion of sucrose that is attained when a hard candy is made by boiling a mixture of sucrose and the specimen of com syrup almost to dryness under very carefully controlled test-conditions. If... 

Most mechanical tests developed for fats are empirical in nature and are usually designed for quality control purposes, and they attempt to simulate consumer sensory perception (3, 4). These large-deformation tests measure hardness-related parameters, which are then compared with textural attributes evaluated by a sensory panel (3, 5). These tests include penetrometry using cone, pin, cylinder and several other geometries (3, 6-12), compression (13), extrusion (13, 14), spreadability (15, 16), texture profile analysis (2), shear tests (13), and sectility measurements (14). These methods are usually simple and rapid, and they require relatively inexpensive equipment (3, 4, 17). The majority of these tests are based on the breakdown of structure and usually yield single-parameter measurements such as hardness, yield stress, and spreadability, among others (4, 17-20). The relationship between these mechanical tests and the structure of a fat has, however, not been established. The ultimate aim of any materials science endeavor is to examine the relationship between structure and macroscopic properties. 

We can use the power and ease of use of today s personal computer to provide an estimate or prediction of the future performance of a process through simulation. The example will consider compliance to a specification for which there is a known downstream effect. In the case of dose uniformity, it may be the additional testing imposed on the quality control laboratory for stage 2 testing, or it could be tablet hardness where values below the specified limit may result in tablet breakage on the packaging equipment, or if the tablets are too hard, may not have sufficient drug release. 

New. A new microscale titration experiment is included, provided by Professor John Richardson from Shippensburg State University, for the analysis of hard-water samples (Experiment 18). The tools an4 techniques used for that experiment could be used to design similar experiments for other titrations if desired. (If your in-stractor tries this with you, I may include your experiment in the next edition ) Two team experiments are added (Experiments 39 and 40) to illustrate the principles presented in Chapter 4 on statistical validation. One is on method validation and quality control, in which different members of teams perform different parts of the validation for a chosen experiment. The other is on proficiency testing, in which you calculate the z-values for all the student results of one or more class experiments and you compare your z-value to see how well you have performed. 

Because of the well defined shape of tablets, crushing tests are regularly and with great success used in the pharmaceutical industry in-line or off-line and often automatically, in combination with an automatic sampler, for monitoring tablet strength. Other modern, fully automated equipment measures tablet weight, thickness, diameter, and hardness for quality control and validation (Fig. 5.32). 

When considering quality control options, simplicity and time required for testing are important considerations. Many traditional tests are not currently found in the modem quality control laboratory because of the time required to prepare the material and conduct the testing. It is also important to consider the amount of sample required for the testing. Analysis of materials is a very large field with a wide variety of chemical and physical techniques available. Thermal analysis and calorimetry have established themselves as important techniques offering not only fundamental characterizations of the chemical and physical nature of materials but also physical measurements that can be correlated back to more traditional measurements of product performance such as hardness, softening, etc. Many of the techniques in this area are quick, accurate and utilize very little material. 

The frequency of sampling and the number of test pieces (or repeat tests) per item sampled depend on circumstances, and obviously financial considerations play an important part. Certain long-winded (and expensive) tests call for one test piece only, although if multiple tests are done the method may be quite variable. The use of a single test piece is hardly satisfactory, but it may be that multiple tests in numbers sufficient to increase precision are totally uneconomic. This is the dilemma that quality control managers (and the writers of specifications) have to face. In a continuous quality control scheme it may be that the number of test pieces at each point is less important than the frequency of testing. 

Short-term stress-strain testing is widely practised in the rubber industry, especially in the form of indentation hardness, tensile strength, and elongation at break. Applications range from quality control and measurement of the state of cure to material specification and a convenient means of monitoring aging resistance. 

Hardness of a material may be determined in several ways (1) resistance to indentation, (2) rebound efficiency, and (3) resistance to scratching. The first method is the most commonly used technique for plastics. Numerous test methods are available for measuring the resistance of a material to indentation, but they differ only in detail. Basically they all use the size of an indent produced by a hardened steel or diamond indentor in the material as an indication of its hardness—the smaller the indent produced, the harder the material, and so the greater the hardness number. Hardness tests are simple, quick, and nondestructive, which account for their wide use for quality control purposes. 

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