Experiment § Reactivity of IPDA
Isophoronediamine (IPDA) is a commonly used cycloaliphatic amine hardener for epoxy resins. The general industrial application mix IPDA with BA (Benzyl alcohol) and SA (Salicylic acid), add epoxy resin to thicken, and sell it as a hardener with good after-resistance. Using IPDA alone as an epoxy resin hardener without adding BA has considerable risk, and the product after room temperature hardening is quite brittle and lacks strength. The photo on the left shows that the hardened product crumbled when pinched for three days at room temperature. If BA is added to the IPDA, the strength is much better (photo on the right). This type of formula is often used as floor paint for dust-free floors. When used in a slightly high-temperature environment in the electronics industry, there are concerns about outgassing. Whether BA will be listed as a substance of concern in the future also needs to be further tracked.
Character § Song-xian, Huang I know
Mr. Song-xian, Huang; expertise: epoxy resin, light-hardening resin, small batch production is in manufacturing department, small batch production team leader, assistant R&D engineer. [Working spirit of trying to fish in the water] When I was a second lieutenant platoon commander in Kinmen in 1997, Song-xian and I served in the same company, serving as a corporal gunner. At that time, there was an unwritten custom in the army. The officers and soldiers who were about to retire would become lazy, and the officers would turn a blind eye and ignore it. Song-xian is one of the only two officers and soldiers I have dealt with more than 300 times, leading the troops to sweep the floor the day before he is discharged from the army. I greatly appreciate this responsible attitude. I made an appointment with Song-xian before he was discharged from the army: I hope to have the opportunity to work together in the future. After Song-xian's work in Kaohsiung ended in 2002, he came to Douliu to work with us: working as a research assistant during the day and studying at the TransWorld University at night. In the early days of Everwide, the work was not difficult, and the welfare and benefits were not on track. Song-xian was able to accompany us without disdain. I dare not forget this friendship. [Attitude to work hard without complaint] Song-xian has been engaged in the research of light hardening adhesive for about two years. It has three years of experience in the application of low-temperature epoxy resin. Song-xian is very familiar with various raw materials, processing procedures, laboratory equipment, and on-site mass production machines. In addition, his Marvel Chemical popularity is suitable for coordinating multiple resources, so he is highly valued by the company. All matters of mass production. Small batch production has the characteristics of small quantity and variety, time-consuming and labor-intensive, trivial and complicated, etc., making Song-xian face significant challenges. In addition to constantly thinking about improving the manufacturing process and machinery and equipment, Song-xian takes the lead when encountering large and urgent orders. [Warm and Helping Gentle Personality] Song-xian silently shows his value at work and enthusiasm everywhere in life. In addition to serving as the chairman of the company's dormitory management participating in the planning and purchasing of company meals, he will also take the initiative to plan and invite company colleagues to travel. Recently, an amazing landscape fish tank appeared in the company's reception room, the latest masterpiece that Song-xian set up at his own expense and volunteered to maintain it. Song-xian is a loyal and honest person, has no bad habits, and has a rare good temper, but unfortunately, he has two shortcomings. The first disadvantage: he is too fat. The second disadvantage: When I asked him to lose weight, otherwise he would not be able to make a girlfriend, he shyly said, "When you meet the person you like, you will naturally have the motivation to lose weight." For this kind of controversy about the order of "lose weight first, then make a girlfriend" or "make a girlfriend first, then lose weight," I don't take him too seriously. In desperation, I had to announce the article: Friends who can help Song-xian successfully introduce his girlfriend will receive an additional month of a year-end bonus.
─Author: Dr. Ming-xu, Li, Everwide Chemical
Knowledge § What is crystalline plastic?
When thermoplastics (linear polymers) have a symmetrical structure and are arranged neatly, the molecular chains will be stacked close to each other to form a crystallization phenomenon. The plastic mentioned above is called a crystalline polymer. The crystalline polymer will absorb latent heat and melt in the melting point region. The crystalline area can be seen under a polarized light microscope, and the structure outside the crystalline region is called Amorphous. The proportion of crystalline region in overall structure is called degree of crystallinity, which is expressed as a percentage (%). Common crystalline polymer and their typical crystallinity are LDPE (55~65%), HDPE (85%), UHMWPE (99%↑), PET (30%), Nylon6,6 (30~35%), PP, PPS, POM, etc. Compared with crystalline polymers, plastics that do not crystallize are called Amorphous polymers, such as ABS, PS, SAN, Acrylates, etc. Due to the slow crystallization rate of a small number of plastics (such as PC, PAr), they need to be placed at high temperatures for a long time or can be induced to crystallize with a solvent. In most applications, they are in an amorphous state. In this case, they can be classified as semi-crystalline polymers. The crystalline regions of crystalline polymer improve overall thermal, mechanical, solvent, and chemical resistance. On the contrary, it increases the difficulty of adhesive adhesion.
Living § On-site continuous improvement (2)
The cluttered and unsatisfactory to-be-processed areas make it difficult to control the number of tubes and obstruct the passage (Figure 1 and Figure 2). Adding racks to place defective products is neat and conducive to control and more efficient use of space (as shown in Figures 3 and 4).
─Author: Ms. Yu-zhi, Ai, Representative of Quality Management, Everwide Chemical
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