Experiment § Effect of filler on resin viscosity
Resins are often mixed with fillers to achieve specific properties. In the stirring process, filler will disperse in liquid resin. From microscopic view, it is a process in which liquid wets solid surface. Moisture attached to powder surface, shape of the powder, surface roughness, etc., all affect the effect of resin wetting powder (Figure 1). Generally, viscosity of the product just be stirred is relatively high, and there will often be a slight decrease in viscosity with time. Excluding the change in the force between the powders, a reasonable explanation is that the surface that was not completely wetted at first was further wetted, so the flow resistance became smaller, and the viscosity decreased. When the amount of addition is very high, the wetting behavior has different results: a high-viscosity fluid appears just after stirring (Figure 2). After standing for a period of time, the sample becomes dry, and it will not recover if it is stirred again (Figure 3). From microscopic view, The resin forces particles to disperse, so it can flow (Figure 4). When standing, few resins further wet the surface. However, the liquid adsorbed by the surface of particles is difficult to flow freely, so the liquid that can move between particles becomes less, and it is even difficult to fill gaps between particles. The powders lose fluid when they get stuck with each other, thus they look like dry lumps (Figure 5).
─Author: Chia-Ying, Chiu
Activity § Interesting things in May
We participated in many activities that are rich in knowledge and culture in May. Japanese suppliers visited and explained the characteristics of raw materials. We hope that we can develop products more suitable for customer needs (Figure 1). In response to public welfare, we purchase tickets for stage plays and provide them to employees, their families and vulnerable children. This performance in Taiwanese language deeply touched the participants in Southern Taiwan (Figures 2, 3). Everwide is considerate to the health of employees and arranges health check-ups every year so that employees can control their own health status (Figure 4). Customers come to the factory for visits and audits, and give suggestions from different points of view for continuous improvement. These processes are constantly enriching us.
Knowledge § What is thermoplastic and thermosetting plastic?
Thermoplastics are linear polymers that can flow after heating and solidify after cooling. This plastic can be processed at higher temperatures, such as injection molding, extrusion molding, blow molding, and so on. What’s more, thermoplastics can also be divided into crystalline types and amorphous types. The former has a melting point of crystalline melting point, but the latter does not, and most of them can be dissolved in specific solvents, only a small part of crystalline thermoplastics lack proper solvent. Common crystalline thermoplastics include PE, PP, PET, Nylon, PPS, PPO, POM, etc; common amorphous thermoplastics include PC, ABS, PMMA, PS, etc. Thermosetting plastic refers to the network structure formed after the polymerization of monomers. Once molded, it will not melt and flow if it is reheated, nor dissolve in solvents, and can only be processed before curing. Common thermosetting plastics are UP, Epoxy, PU, Phenolic, Melamine, and so on.
Living § Marathon
I was passionate about outdoor activities before my injury, and the only exercise I can do after injury is running. Since I often go to the playground to run on weekends, I have met many like-minded friends who invited me to join the sports club. At first I only ran 2~3 kilometers, then I tried the first 21 kilometers. After that, I thought 21 kilometers is not difficult, then 42 kilometers marathon should be no problem. After nearly a year of preparation, I signed up for marathon. After running that day, I realized that marathon is not as simple as adding two half-marathon together. It also made me deeply realize that sports require long-term accumulation. On April 14, 2019, I completed my 40th marathon at the age of 40. Someone asked me, “What’s your next goal?” Actually, I haven't have any answer yet. I only know that people have to exercise if they want to live. I asked myself, “What does marathon bring me?” Besides being happy and developing exercise habits, I can use my feet to see the beautiful scenery and things in Taiwan.
─Author: Chi-Jui, Yu
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