Everwide Newsletter-No.30

The transient mode is further divided into two types: stress relaxation and creep. In the latter case, a rheometer can suddenly apply a specific force to the fluid and measure the amount of deformation of the liquid over time. By repeating this method, as long as we experiment with the creep behavior under various forces, we can understand the force field under which the fluid can flow obviously and describe the thixotropic behavior more accurately.

The dynamic test uses the simple harmonic motion of parallel plates to decompose the viscoelastic behavior of the fluid into two characteristics: viscosity and elasticity at different amplitudes, different frequencies, different times, and different temperatures. Based on the parameters obtained from these two characteristics, the time-temperature equivalence principle can predict the fluid behavior at very high or very low shear rates, very short time or long term.

We are now starting to conduct preliminary experiments using a rheometer. We hope that by introducing a rotary rheometer, our analytical ability can be improved, our customers can get better service, and our industry standard can be improved.

─Author: Dr. Ming-xu, Li, Everwide Chemical

Mr. Ye-xu, Li, Ph.D., Institute of Chemical Engineering, National Chiao Tung University, specialty: epoxy resin, affiliated laboratory: Lab-4.

People say, "Get up from where you fall." But Ye-xu, Li said, "Wherever you fall, you have to find a way to live better than when you fell. Don't waste time and get up again!" In my view, everyone's setbacks and bifurcation points are different in his life. As long as you master your direction and are willing to work hard to keep going, he believes that "as long as you have the ability, everything is not a problem!"

[Favorite field of chemistry] I like chemistry, and a simple idea made Ye-xu, Li step into the field of chemistry. [Grasp the opportunity when it comes] "When the opportunity comes, you must have the courage to challenge!" The courage to challenge is another remarkable trait of Ye-xu, Li's personality. He believes that people should challenge different opportunities at different times. [It is essential to find the right resources] Experience and resources should be passed on continuously. Everyone will have blind spots in learning and can't get started because everyone sees things from different angles and needs. When you try to digest it with your way of understanding and then ask questions, you can put yourself in the shoes to clarify the crux of your problem and help you quickly. Filter out the correct information to help you save the most learning path. [Perseverance to get to the bottom of everything] Stepping into the unfathomable field of chemical resins, the most significant driving force for Ye-xu, Li to grit his teeth even if he has occasional setbacks is his endless curiosity. He always tries to solve his doubts as soon as possible when he encounters a problem and does not allow any hesitation in his learning steps. "Even if I don't understand or don't know how, I ask myself to find the answer within a day, at least to know where to find resources, Which direction to start from, this is the standard I set for myself." With this perseverance to get to the bottom and learn actively, Ye-xu, Li has built a solid R&D technical strength from scratch. To this day, he continues to encourage himself to accept new challenges, specializes in epoxy resin technology, and cultivate their all-around concepts and strengths. In the future, his R&D territory will expand rapidly with his strong ambition for knowledge!

─Author: Mr. Yun-xian, Liu, Director of Labor Safety, Everwide Chemical

Thermal shock refers to a material that repeatedly experiences a wide range of temperature changes in a short period. The electronic components in jet airliners, for example, are the most obvious example. The purpose of the thermal shock test is to evaluate the material's ability to withstand repeated changes between extremely high temperature and extremely low temperature and to test the chemical changes or physical damage caused by thermal expansion and contraction in the shortest time. Generally, the thermal shock tester structure can be divided into three parts: high-temperature area, test area, and low-temperature area. The tested object is placed in the test area statically, and the temperature of the test area can be quickly changed by switching between hot and cold air paths.

Compared with thermal shock, the thermal cycle has a slower rate of temperature change, and the conditions are less extreme. For example, the cold and heat cycle test can evaluate the environmental conditions encountered in the use of electronic, electrical, food, vehicle, metal, chemical, building materials, and other products. A programmable constant temperature and humidity test machine often perform the cold and heat cycle test. In addition to temperature changes, experiments can also be carried out for changes in humidity. The figure on the left shows the "Cold and Heat Shock Tester" currently used by Everwide Chemical.

Everyone is often using a vacuum oven to vacuum, and there is a phenomenon that I don't know if anyone has discovered. Before vacuuming, the temperature of the vacuum oven is the same as room temperature; as the vacuum level increases, the temperature will drop by about two degrees. After the vacuum is broken, the temperature returns to room temperature. What is the reason for this phenomenon? Does vacuum level affect temperature? Please observe more when vacuuming, and share my explanation of this phenomenon with you next time.

Figure 1 shows that the vacuum degree is 0cmHg, and the temperature is 27.6oC before the vacuum oven is evacuated.

Figure 2 shows that when the vacuum oven is evacuated, the vacuum degree is 76cmHg, and the temperature is 25.1oC.

─Author: Dr. Ye-xu, Li, Everwide Chemical