Everwide Newsletter No.144

Epoxy resin has excellent electrical insulation properties and is used in electronic motor equipment. However, shrinkage stress and thermal stress cannot be avoided during the curing of epoxy resin. Shrinkage stress results from the reaction of the resin with the curing agent and the reduction in volume. Thermal stress is the release of heat from the reaction of the resin with the hardener, or the high-temperature baking process, leaving the resin above room temperature, and then the stress caused by the expansion and contraction of the component when it cools to room temperature after the reaction. Excessive stress will cause the product to crack. The commonly used methods to reduce stress are as follows: 1. Add fillers to reduce shrinkage and linear expansivity, while suppressing the highest heating temperature. 2. Use a curing agent with low heat to reduce the temperature rise during curing. 3. Increasing the thickness of the resin or using flexible resin can improve the tolerance of stress. Generally, when the epoxy resin is cured and cooled or tested in an environment, the resin often cracks due to too much stress. Figure 1 is a photo of the washer test specimen cracked. For the test method, please refer to the 35th and 36th bi-weekly reports. We are committed to developing flexible products so that the cured material has the characteristics of anti-cracking and resistance to cold and heat shock (Figure 2).

—Author： Mrs. Rong-Xin, Lin

What can we do on the top floor? Originally, we wanted to install solar panels to generate electricity, because that would be environmentally friendly and reduce the temperature of the house in summer. However, that would require an investment of tens of millions of Taiwan dollars, and it would take more than ten years to make a profit, but the long-term backlog of funds is not a good choice. We are also considering looking for a gardening company to make a "green roof" (sky garden). But the reality is that the maintenance of the flat garden is already very troublesome, so we really don't have time to create it in the air. Finally, we decided to DIY as a small nursery. In February last year, we used the holiday for soil preparation and planting, and now there are about 500 Murraya paniculate. From February this year, we moved the new saplings to the cultivation soft pots so that they can be transplanted and managed in the future. If we use holidays to do it, it is expected to take a year. What seems to be a simple job is actually not simple, right?

The density of epoxy resin without filler is about 1.20, but the density of epoxy resin with filler can be as high as 2.56 or more (taking 85% filled AlN as an example). The production of epoxy resin with a density of less than 1 can use a foaming agent to foam or add hollow glass spheres to reduce the density of the epoxy resin. There are many types of foaming agents. If you choose expanded powder for closed-cell foaming, its density can be as low as 0.2, and hollow glass spheres are also closed-cell foaming, and their density can be as low as 0.5.

Last month I went to China with my colleagues and our first stop was to visit an instrument manufacturer in Kunshan. When I first got to the gate, it was hard to imagine that this was an instrument factory, because there were only about ten people inside to take care of everything. We spent two days there doing experiments and found some flaws that needed fixing, but I was impressed by their effort. On the morning of the third day, we took a bus to Shanghai. A driver on the road shared his story with us: when he was young, in addition to sleeping, he drove day and night to make money, because he wanted to pay off the loan quickly, but it led to occupational disease. On one occasion, while carrying his luggage, he suddenly suffered a vertebrae dislocation, leaving him paralyzed and without feeling and then It took an operation and a long rehabilitation to get him back to health. "The process was painful," he said. "I had to overcome everything in order to stand up." The story of his life shocked me, so the two-hour drive from Shanghai passed quickly. The purpose of Shanghai is to buy some of the professional books for everyone to reference. The bookstore was a surprise to me because it looks like a department store. The six floors below are all selling books and the interior is connected by an electric escalator. All kinds of books are stacked on the shelves, so the sales volume is amazing. Having witnessed the Chinese people's pursuit of knowledge and makes me worry whether we Taiwanese people are curious enough. In the evening, we took a walk on the Bund as a benefit for business trips. At the same time, we also found that Shanghai may be more prosperous than our Taipei City. But I am not used to eating on the mainland. In addition to the heavy taste, the service staff's attitude to customers is not so good, so the mainland's service industry still has room for improvement. This trip allowed me to gain a lot of knowledge, because I not only learned about the efforts of other people, but also realized the strength of life, and at the same time found my own shortcomings. I hope to share my knowledge with you, pursue progress, and create a better future together.

─Author: Mrs. Gen-Chang, Shi