In our last post we showed how the chemical conversion and glass transition temperature (Tg) were correlated to the viscosity during a non-isothermal curing profile.  We will continue our analysis of the aborted rheometer data in this post. In the data presented in Part 8, the heating rate was held constant.  In reality, we did experiments at several heating rates and the ... [Click to Continue...]

In our last post we provided the background on how to correlate the viscosity, conversion, and Tg during non-isothermal curing.  We used the technique in the figure to the left to “freeze the action” along the viscosity profile and use DSC to probe how the curing was progressing. In the next figure, the percent conversion is plotted as a function of time on the left axis and ... [Click to Continue...]

Previously we described how to measure the viscosity profiles during non-isothermal curing typical for many prepreg and composite processing situations (lamination, autoclave, etc.).  The chemistry is tailored to allow for the resin to soften and flow with the chemical reaction occurring at an elevated temperature.  The elevated cure initiation is accomplished using a latent ... [Click to Continue...]

I thought I would continue the Thursday “break-ups” since the topic is an interesting one.  This post will talk about why having fun is so important. Can you think of a time, a project, a company, or any other organization where you actually had a blast working?  Too bad for those who can’t think of an occasion, but in all honesty, there has to be a situation where everyone ... [Click to Continue...]

Our last post introduced non-isothermal rheology as a characterization technique to measure the viscosity during processing (typically non-isothermal temperature profiles are used).  A good example of how rheological methods can be used to optimize a process is to consider a composite lamination process.  In the figure on the left, B-staged prepregs are sandwiched between to ... [Click to Continue...]