Bioresorbable screws - Essay Example

It is necessary to examine the three stages of the process and anticipate probable flaws in the final product resulting from decisions made at each stage. The melting phase of injection molding is essential to achieve the most even blending possible of the injected material. Too low a temperature may prevent the material from blending into a homogeneous mixture. If the temperature is too high there is a possibility that some material will be lost through evaporation, or combustion under the right circumstances.

In any event, excess temperature would result in an inefficient process where energy is wasted, thus raising costs unnecessarily. The speed of the injection of the melt represents a danger as well, too slow and there is a possibility that a portion of the melt may partially solidify before the mixture is sealed into the pressure. Still there is the question of how fast the process absolutely needs to be for industrial efficiency. When the desired mixture is achieved, the pressure inside the injection mold must be intense enough to allow solidification while an optimum distribution of molecules is present, to ensure homogeneity.

One possible experimental design is to locate the melting point of hydroxyapatite and then deliver five samples into separate heating elements at ascending 10° increments above that melting point. . ptimal temperature is determined in this method, material samples heated to the same temperature can be injected into new samples at five different speeds in progressively faster increments which are then sealed prior to hardening. Using the same stress testing, the optimal temperature at the optimal injection speed could then be used in a third experiment involving five samples at different increments of pressure.

The stress tests can be repeated. In terms of power analysis, this design allows adjustability and the potential for precision. Five samples for each phase of testing create an experiment that permits the investigator to pinpoint the optimal conditions most conducive to the structural outcome desired. Five samples in 2° increments allow inference of the optimal conditions without redundancy. If at either of these experimental phases there are inconclusive findings in stress testing, then the increment requiring the least amount of energy should be recommended.

This proposed experimental design could be evaluated using logistic regression. If the goal is to assess whether the product will break at a certain level of pressure, then whether breakage occurs is a categorical dependent variable, but this experiment proposes continuous data based upon temperature, injection speed, and mold pressure. This statistical method should provide insights concerning the optimal combination of factors to inform an attempt at reliability testing. For the purposes of this experiment, the continuous gradations in terms of temperature, injection speed, and mold pressure are necessary to provide a range of information that optimizes the probability of finding the most advantageous method.

A repetition of these tests can be used to reduce the probability of anomalies and