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Everwide Newsletter No.163

Updated: Aug 6, 2021


Experiment § DSC Measures the reactivity of hot melt adhesives

DSC can measure the reactivity of epoxy resin hot melt adhesive (Figure 1). Figures 2 and 3 show the detailed structure of the DSC. Put the unreacted resin in the sample tank and scan directly by heating up. It can be found that the exothermic signal becomes more evident above 120°C and reaches a peak value at 159°C (Figure 4). It means that the reaction before 120°C is slow, but it does not mean that there is no reaction. If the blank sample tank is heated to 150°C, and then the unreacted resin is quickly put in, the experiment of constant temperature scanning can be performed. The graph in Figure 4 shows that the exothermic peak is at 2.46 minutes, indicating that the heat of reaction of the resin reaches the maximum at this time, and the reaction is the fastest at this time. Figures 4 and 5 measure the reaction heat between 400~470 J/g (when the measurement method and the judgment baseline are different, the obtained reaction heat will be different). Assuming that the specific heat of the resin is 1.5 J/gK, the heat of reaction can theoretically heat the hot melt adhesive to 300 degrees by itself. Of course, most of the reaction heat is absorbed by the DSC furnace. In industrial production, the reaction heat of hot melt adhesive is also absorbed by the mold, and the temperature of the resin will not increase that much. The enlightenment of this experiment: hot melt glue must first clarify the reaction temperature and then master the processing parameters. The resin reacts slowly at low temperature, and it will quickly release heat at high temperature, which will quickly end most of the reactions. Where is the boundary between "low temperature" and "high temperature"? What will the impact be? It is the "eyebrow corner" that developers need to understand.

─ Author: Dr. Ye-Xu, Li

 

Activity § Year-end meeting

The day before the Lunar New Year holiday is the year-end meeting, allowing everyone to say goodbye to the past year and explore possible opportunities in the future. This year we asked colleagues to fill out the questionnaire and post it on the booklet: Did you have a happy job last year? What new things did you learn? Then there are reports from various units and awards to the colleagues who took the examination and the outstanding colleagues who voted for last year. In addition, introduce the great speech website TED, broadcast Ke Wenzhe's speech "The Wisdom of Life and Death," broadcast the Mayday song "Second Life," and introduce the management master Brother Han's views on life. In the afternoon, we will explain the major development projects of the year, introduce the stories and advertisements of the eternal knight, and enjoy the movie "Mr. No Problem." After the meeting, colleagues are invited to write an experience; the topic is: What kind of second life do you want to have? In the meeting, we used questionnaires, awards, songs, advertisements, movies, reports, etc., to remind colleagues: thinking about the meaning of life. We want to share the simple version of the manual with you and use it to wish you a happy new year.

 

Knowledge § What is the function of the filler?

Filler definition: For strength improvement or cost reduction, inactive substances added to plastics are generally called fillers. The functions of fillers are as follows: 1. Improve specific physical and mechanical properties. For example: reduce hardening shrinkage and thermal expansion coefficient, resist cracking, increase hardness, increase specific gravity, increase thermal conductivity, etc. 2. Improvement of processability. For example: improve viscosity, impart anti-sagging characteristics, provide abrasive cutting and other properties. 3. Reduce cost considerations. For example: changing the proportion of resin, designing incremental resin, etc.

 

Living & Do something you haven't done before!

Everyone, every day, seems to be repeating the same things: get up, eat breakfast, go to work, eat lunch, work, get off work, eat dinner, rest, sleep day after day! But to me, a life without "adventure" seems to be something missing. Therefore, I decided to do something I had never done before and let myself "adventure" a bit. I started this project last year: In October, I arranged a trip to Yilan-Hualian. For the first time in my life, I went to the eastern part of Taiwan. The beautiful scenery made people relax. In November, I visited Hong Kong. I went to the narrowest alley in the lively city of Central Hong Kong and saw many people who are not well-off, working hard for their lives in the dark and messy corners. In December, I went to the new book launch conference of young and cutting-edge writers and watched. She smiled shyly on the stage, but was full of confidence, bravely and firmly introduced herself and promoted herself; this New Year's Day, I came to Taitung Sanxiantai to watch the sunrise, ringing the wishing bell, but praying for a new one in my heart. As a farmer's child, my simplest wish is that the weather will be good for the country and the people in peace every year. These things are things I have never done before. If you haven't done it, it won't be so good; it feels very different if you have done it! My friend, how long have you not "adventured"? Let yourself always keep your young heart and escape from the comfortable environment; life will be worthwhile! Let's get started and do something that we have never done before!

─ Author: Mr. Jin-Rng, Li





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