Experiment § Tritanᵀᴹ special photocuring adhesive
Many plastic containers are made of polycarbonate (PC). PC is light, transparent, impact resistant, and easy to be processed. However, PC is synthesized by BPA. Although the amount of BPA remaining in the product is too less to be detected, and there is no dissolving problem in cold water, and only a small amount will be released in extreme conditions in hot water, the new trend is still looking for alternatives, which is advertised "BPA free". A plastic called Tritan produced by Eastman is a new option. It is a copolyester copolymerized by different monomers, which does not contain BPA, and its other characteristics are quite similar to PC. The containers in Figure 1-4 were originally manufactured by PC, but now Tritan products are common. What’s more, Cup body and cup feet in figure 3, pot body and handle in figure 4 are all bonded by photocuring resin. The adhesives originally applied to PC and PMMA did not have good effect on Tritan, some could not swell the surface, and some induced crystallization. Thus, based on the material properties of Tritan, we developed a special photocuring adhesive—JD943. Figure 5 shows a 2 liter kettle with a handle using JD943 to bond, and then loaded with a 3 kg object. There is no problem at 60°C/3 days +90°C/1hr. The theory of plastics adhesion is that different materials should choose different monomers, adopt different strategies, and even use different designs. We are very interested in adhesion and welcome everyone to discuss new materials together.
─ Author： Te-Chung, Chen
Activity § Congratulations to NCKU Formula Racing
At the end of last year, the NCKU Formula Racing visited our factory (Thriving, No. 289), and we sponsored them resin for making car bodies. This year they went to Japan to participate competition successfully and became the only two electric car in Taiwan passing the competition test. So far, we have sponsored resin to the racing teams of NFU, STUST and NCKU, which is another way to attend competition. We are proud of them.
Knowledge § Can sealant made of MS resin be soaked prolongedly?
Most MS resins have high water absorption. If it is soaked in water for a long time, the strength may become worse, so it is not recommended to do this; on the contrary, soaking in water for a short time has a limited effect on MS resins, since water absorbed by the colloid will evaporate in a later drying environment. If the colloid is not in contact with water directly, such as adhesion between workpieces, there is no concern about lowering its strength. Thus, it is recommended that using Silicone RTV1 for sealing materials which is exposed to water for a long time, because its water absorption rate is low. After the water absorption rate reaches saturation, the performance of the colloid tends to be stable.
Living § Do you have real wealth?
The book says, "Besides material wealth, spiritually rich is also indispensable for truly wealthy people." This statement is not false at all. Magazines often report that big bosses often complain that they don't have time to accompany their families, to achieve their dreams, and even to stay healthy. Actually, you are not rich when you have regret in life. Because life cannot be repeated, it is very important to take into account all these needs and achieve real wealth, especially "management": Efficient work comes from careful planning beforehand; good interpersonal relationships require time to operate; a healthy body comes from good habits. According to the WHO survey, only 5% people are healthy in the world, and most people are in sub-health state: Sub-health state refers to the critical state between health and disease. That is, people's mental or physical state is in confusion, but there is no obvious pathological features. Someone once compared health to an antique teacup that was on the edge of the table. When the cup (health) falls and breaks, you may ask doctor: "Can this condition be remedied? Is the cost expensive?" In fact, everyone knows that as long as you gently push the cup inward, you can reduce the chance of falling. This is the concept put forward by "Preventive healthcare". We should take care of our own health first, and then take care of the relatives and friends, and finally reach the goal of everyone being healthy.
─Author：Jung-Hsin, Lin
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