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Everwide newsletter No.395


Experiment § Cracking kinetic

The long-term heat aging test is too lengthy in practice, and the cracking kinetics can be used to evaluate the pyrolysis status of the species after long-term heat aging. The criteria for aging failure depend on the application of the case. For example, appearance may be determined by the yellowing index; the structure may be determined by shear strength, etc. The Conversion Level, the critical calculation factor of lysis kinetics, needs to be judged empirically. We select the appropriate activation energy as the calculation benchmark, and different key calculation factors will have different activation energy. The higher the value of activation energy, the less likely it is to age, and the percentage conversion of cracking will vary greatly between different activation energy (Figure 1-3). Modulated TGA is used to determine the appropriate activation energy data; for example, the smoother position of the curve in Figure 4 will not be too biased when selected to achieve a reasonable cracking kinetic operation.

─Author: Mr. Zhi-Yu, Huang

 

Activity § 2023 Exhibition Information

In the post-pandemic era, countries have returned to normal operations, and exhibiting activities have gradually returned to pre-epidemic activities. Last year, there were three exhibitions, and the overall performance gave us confidence. A total of five exhibitions are planned this year: 04/12~04/15 Taipei AMPA (Taipei International Auto and Motorcycle Parts Exhibition), 05/24~05/26 INAPA(Indonesia International Auto Parts, Accessories, and Equip Exhibition), 06/21~06/24 NEPCON Thailand, 09/06~09/08 NEPCON Vietnam, 10/25~10/27 OPTO Taiwan. We invite you to visit the exhibition booth and find out how much we have improved!

 

Knowledge § Why is PU prone to bubbles?

The isocyanates in PU react with water to produce amines and carbon dioxide, the latter being gases and the source of bubbles. Each mole of isocyanate reacts with one mole's water to produce one mole's carbon dioxide. Assuming that the specific gravity of PU is 1, the structure of one molar of carbon dioxide is 44 grams, the original volume in the resin is about 44 milliliters, and the volume will expand to 22.4 liters when it becomes gas. When the isocyanate reacts to produce carbon dioxide, PU will appear solid, such as PU hot melt glue; at this time, PU will only lose a small part of the volume of carbon dioxide, and carbon dioxide will diffuse outside PU to present a volume of 22.4 liters. If the PU has not crosslinked into a solid when the isocyanate reaction produces carbon dioxide, the carbon dioxide will immediately expand from 44 ml to 22.4 liters, turning into apparent bubbles.

 

Living § Challenge Hehuanshan East Peak

On holiday, I made an appointment with my colleagues to climb the Hehuanshan East Peak (3421m). The first time I challenged the mountain, I was so excited that I completely forgot the fatigue of waking up early. Unexpectedly, I couldn't adapt to the thin air, and I developed symptoms of "altitude sickness": after less than five minutes of departure, I began to feel that I couldn't breathe air, and I even couldn't breathe after walking a few steps, and the rest time was longer than walking. After about 300 meters, I was frequently dizzy and pale, unable to continue. For safety, I had to turn back to the trailhead to rest. After my colleagues successfully reached the summit, they shared beautiful photos of the mountains with me, which made me envious. They also said that the distance is not difficult, as long as I am prepared to adapt to the altitude, and physical fitness is not a problem, which gave me a lot of confidence, and I decided to choose a time to come back to the challenge. This mountaineering experience gave me a great impression: in everything you do, the focus is not on winning or losing with others but on challenging your limits. Only by overcoming oneself is real progress. Even if you fail the challenge, it is not bad, but let yourself know what room for improvement is. I will find another opportunity to practice climbing and exercise my physical fitness; as long as I continue to work hard, I will definitely be able to climb to the top next time and enjoy the infinite beauty of the mountain.

——Author: Ms. Ting-Yu, Lai



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