Experiment § Electrical insulation experiment of epoxy resin
Epoxy resin has both processability, corrosion resistance, and excellent electrical insulation, and it is widely used in the insulation filling of electronic motors: such as motors, dry-type transformers, current transformers, comparators, etc. Electrical insulation can be known by measuring the surface resistance and volume resistance of the material and for the method, please refer to the third issue of the bi-weekly report. Generally, the temperature of motor products will rise during operation, small parts such as transformers will rise to 60~70 degrees, and the temperature of large motors such as motors will exceed 100 degrees or even 150 degrees, therefore, the data measured at room temperature before is not suitable.
This requires special instruments and fixtures when performing experiments at high temperatures, or ask customers to make actual finished products and put them in an oven for testing. Both methods are expensive and time-consuming. We found that the resin was poured into an iron can (Picture 1), and then placed in an oven to simulate the heating of the customer's workpiece (Picture 2). Measure the change of resistance at the same time, you can compare the resistance change of different materials at different times, different temperatures, and different reaction conditions (Figure 3). Although this test method is different from the actual situation, it is still very helpful to the research and development of resin formulations. We can use this method to explore which variables will affect the characteristics of resistance at high temperatures and accelerate our research and development speed.
─Author: Mr. Zhan-Yu, Chen
Activity § Come to a different course!
Our R&D colleagues have 3 hours of education and training every Wednesday night for nearly 5 years. 30 lessons per year, 2 to 3 hours per lesson. Most of these courses are related to product development, drug introduction, industrial applications, and market trends, and focus on narration. This year, the manufacturing department opened a precedent for practical activities, and the R&D department also designed the first practical course on composite materials! There are 3 lecturers who arranged 3 courses, from introduction, implementation to review of results, everything can be rewarding. The photos prove that everyone is fully focused and working hard to do their homework. It looks a lot like an art and craft course, right? But this is the real learning situation of prepreg cutting and stromatolite. After 2 weeks, the lecturer will announce the strength of each colleague’s own test sheet and if the data fluctuates too much, it will become a discussion textbook! At the end of the activity is the exam. One of the questions is: What are the possible reasons for the data bounce? This shows that the practical course is very accurate and will never go wrong.
Knowledge § Breaking mechanism of thermosetting resin (2)
Cavitation deformation usually occurs in rubber-toughened thermosetting resin systems. In the cured thermosetting resin, rubber particles mostly exhibit phase separation and are dispersed on the resin substrate. Think of the resin as the "sea", and the rubber particles are naturally like "islands", so they are often called island structures. The existence of these rubber particles can convert the stress that appears in one direction into three-dimensional triaxial stress, and then achieve the effect of dispersing the stress. On the other hand, in the presence of stress, the amount of volume change between the resin and the rubber is not the same. As far as the stretching mechanism is concerned, the volume of the resin will expand, and the volume of the ideal rubber will not change. In the case of high stress, the interface between the resin and the rubber particles will delaminate and form cavities due to the different expansion ratio, which consumes a large amount of fracture energy and this phenomenon is called cavitation deformation. A good formula design must use the characteristics of these two rupture mechanisms at the same time, adjust the Tg and choose the appropriate morphology, so as to be able to endure numerous cracks at the same time, expand the area of energy consumption, and exert the effect of multiplying and doubling.
Living § Icebreaker trip in Hokkaido
The icebreaker, as the name suggests, is equipped with icebreaking equipment on the ship to break the melted ice on the sea while it is melting to open a channel on the sea to facilitate fishermen's fishing operations. This winter, I went to Northland to explore the mystery of the icebreaker. Because of the constant snowstorms in Hokkaido before the trip, news of passengers being trapped was spread, so I originally thought that the trip would be interrupted or canceled, but luckily, it finally took place. It is still snowing in Hokkaido at the end of February, so it is very beautiful wherever it goes. The temperature was once frighteningly low, so you must be cautious when walking on the road to avoid slips and falls.
In the Sounkyo Gorge at minus 18 degrees, in order to shoot the magnificent meteor waterfall, my right hand was completely frostbitten, and I couldn't move it, and the joints of my fingers were bleeding, which was very impressive. Because the beautiful Otaru Canal is covered by snow, there are staff members from time to time to remove the snow to prevent people from slipping. There is also a hidden version of the attraction in Otaru: the steam clock, the only steam clock in the world, one in Vancouver, Canada, and the other in Otaru. In addition to telling the time on the hour, the steam clock plays 5 scale melodies with steam every 15 minutes, which is very fun! The craziest thing about this trip was eating six-color ice cream at minus 10 degrees. How does it feel to eat ice cream in the ice and snow? I hope you can try it yourself if you have the opportunity.
—Author: Miss. Heng-Rong, Li
