Experiment § The phenomenon of curing shrinkage
Shrinkage is a phenomenon in which the volume of the resin changes from liquid to solid. When the mass is unchanged, the shrinkage rate can be calculated by measuring the density of liquid and solid (Thriving No. 11). When the pure epoxy resin cures, there will be a shrinkage rate of 3-5%; After adding inorganic fillers, the shrinkage rate will decrease, but the volume of filler will not change. Therefore, the shrinkage of the formula is related to the volume ratio of the resin. The shrinkage phenomenon is not obvious in the application of relatively small injection volume, and it is often only the trace of the resin level being lowered. However, when the filling volume is large, the shrinkage becomes a big defect of the product. In order to understand how shrinkage occurs, we experiment with transparent resin: Figure 1 shows a cylinder molded by resin curing, weighing 1kgWhen baking and curing at 70°C, the reaction exotherms significantly, so the temperature in the middle of the cylinder will be higher than the side: The middle cures first, and the sides cure later, cause the shrinkage dents occur on the sides. If the baking temperature is increased to 100°C, the overall reaction is very intense, so the shrinkage will be very uneven. Sometimes there is no shrinkage in appearance, but cracks and voids occur inside, which are caused by alternative shrinkage (Figure 2). The baking temperature decreases, the amount of catalyst is reduced, so the curing reaction will slow down. In this way, the resin can be heated uniformly, the exothermic reaction has a chance to balance, and the entire resin is cured simultaneouslyFigure 3 shows it is baked at 50°C. Shrinkage may occur on the top of the cylinder, therefore a cured product with complete appearance can be obtained.
─Author: Chia-Ching, Lin
Activity § Things in November
Gradually approaching the end of 2018, many data for this year will be roughly confirmed in November. For example, we has cooperated with dealer—Hengyen Enterprise to participate in TAITRA for 8 consecutive years (Figure 1); a total of 7 customers conducted supplier audit with us (Figure 2); We have 30 sessions of R&D education and training each year, and the last session this year is on November 7 (Figure 3); It has been a year since the trash picking activities on Dougong 2nd Road have been held, with a total of 25 actions (Figure 4). These data show that: 1. Only by constantly accepting tests in the market can the product have credibility; 2. In addition to better performance, customers also care about how things are made; 3. The creation and transmission of knowledge is always the key to organizational development; 4. All processes require long-term persistence. Our data continues to accumulate.
Knowledge § What is the principle of DEA?
DEA (Dielectric analyzer) is that placing a material between two electrodes to measure the capacitance and conductance of the material in a specific frequency AC electric field. Capacitance refers to the ability of a material to store charge. Conductance refers to the ability of a material to transfer electric charge. These two properties are related to the motion of molecules and are affected by time, temperature, and frequency. Through the DEA experiment, the dielectric constant, loss factor, ion conductivity, Tg, reaction rate, etc. of the material can be obtained, which can be used to study chemical reactions, rheology, and molecular motion of viscoelastic substances. These properties can also be measured with DSC, DMA, and rheometers. However DEA is not used to replace them, but to cooperate with each other to gain a deeper understanding of the properties of materials.
Living § A dog accompanied us to climb the mountain
Participated in the South Section 2 of Central Mountains Hiking Route in October: Taitung Siangyang entered, Nantou Dongpu exited. The total length is 88 kilometers, and it has actually walked for 9 days and climbed 8 mountains. On the third day of the trip, we ran into the mountaineering team in the opposite direction. They said that the dog and them walked here from Dongpu. The next day, instead of crossing Lacuyin Creek with the team, the dog followed us back towards Dongpu (Figure 1). But how can a dog pass through such a narrow stone wall that requires a rope to pass? In fact, we worried too much. The dog had a secret path, so he disappeared, and then sticking its head out from the front (Figure 2). We couldn't see the exhaustion of the dog at all, but as long as he caught the opportunity, he would take a nap; after a few minutes, he would be full of energy (Figure 3). The dog seemed to be familiar with the path, so he could use his nose to recognize the direction we were about to go. Several times he stood on a high point in front of him, and below him was a mountain house (Figure 4, Lulu Valley Mountain House). Figure 5 was taken in Xiuguluan Mountain. I was panting, but the dog still felt easy. Figure 6 was taken at "Baiyang Gold Mine House" Mr. Su fried a large scallion pancake for the dog to eat and thanked for his company. I ever thought about whether to bring the dog back to the Douliu factory? But watching him happily wandering in the mountains every day, I couldn't bear to turn him into a watchdog. On the last day, we said goodbye to the dog at the "Guangao Workstation". The dog saw that we were about to end our trip, so he went to the "Ba Da Shiou" with another mountaineering team. The dog accompanied us for more than seventy kilometers. If we add the distance that he accompanied other teams, it must exceed 200 kilometers. What a passionate dog! How can we be like him?
─Author: Ming-Hsu, Li
