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2014年9月28日4 分鐘

Everwide Newsletter No.179

Experiment § Acrylic resin with a low thermal expansion coefficient

Light-curable resins used in industry can be divided into free radical type acrylic resins and ion polymerization type epoxy resins. The former reacts quickly, with a large shrinkage rate and coefficient of thermal expansion. The latter has a slower response and lower shrinkage and coefficient of thermal expansion. Many lenses used outdoors, such as to monitor lenses, mostly require low CTE. The reason is that when the monitor is placed outdoors, the temperature inside the lens module can sometimes be as high as 80°C, and the low temperature may be minus 20°C. If the CTE of the glue used to fix the lens is too large, it will cause the lens to lose focus, and the image will be blurred. Although light-curing epoxy resin has a better effect on lens fixing, most manufacturers choose acrylic resin as the glue for lens fixing under the consideration of cost and efficiency. How can the CTE of acrylic resin be made similar to that of epoxy resin?

  1. Choose acrylic resin with a larger molecular weight.

  2. Add a specific proportion of filler.

  3. Use a deep curing photoinitiator.

Using these three principles to make appropriate components can greatly reduce CTE. In addition, there is also a big relationship between lens fixing and processing methods, such as uniform control of the amount of glue, simultaneous exposure of multiple points, all of which can make the stress distribution between the lens and the lens holder as uniform and balanced as possible. Through the research of materials and processing methods, the displacement of the lens can be minimized when the temperature changes.

─ Author: Mr. Zhi-Yu, Huang


Activity § Energy-saving membrane project

The weather is hot, no matter how big the air conditioner is, we can't feel cool, which has something to do with the direct sunlight into the house because the infrared rays in the light penetrate the windows and it is absorbed by things in the room and emits heat. In response to this problem, we put explosion-proof and energy-saving films on all the glass in the factory (pictures 1~5). This energy-saving film has 80% light transmittance and can block 90% of infrared rays. Analyzed by a thermal flow tester (picture 6), about 75% of the heat can be blocked. Colleagues unanimously said: The room temperature has really dropped a lot! We are improving the sultry environment year by year. For example, we have worked hard step by step from ventilation, exhaust, curtains, shade nets, compartments, and heat insulation films, and we have achieved good results. To create a better working environment, the action will not end.


Knowledge § What are the characteristics of epoxy resin?

The characteristics of epoxy resin have the following seven points.

  1. Excellent mechanical properties: Epoxy resin has strong cohesion, and its mechanical strength is better than ordinary resins.

  2. Good bonding strength: After the epoxy resin reacts with amines, the structure will produce hydroxyl groups, and it has good adhesion to many materials.

  3. Low curing shrinkage: The curing shrinkage of epoxy resin is only 1~2%, which is one of the smallest types of thermosetting plastics.

  4. Good processing performance: The epoxy resin will not produce volatile substances when it is cured, so it can be suitable for many different processing conditions.

  5. Good electrical performance: The volume resistance of epoxy resin is about 1015ohm-cm or more, which is a resin material with very good insulation.

  6. High chemical stability: Epoxy resin can withstand the corrosion of various acids, alkalis, and salts without damage.

  7. Good heat resistance: The cured product of epoxy resin can generally heat up to about 100°C, and the resin of special heat-resistant grade can heat up to 200°C or more.


Living § The days of my internship at Everwide

I went to Everwide Chemistry for an internship because I don’t have to go on to study and I hope to plan my future well. Stepping into the workplace early and experiencing work is more helpful to your life. The difference between Everwide and the company I used to work for is that Everwide will not treat employees as workers or robots, but treat employees as company assets and will not only conduct employee education and training but also dispatch employees for training and encourage everyone to obtain certificates. Even our interns are no exception: the company still sends us out to attend classes to participate in the weekly education and training of the manufacturing department, sends us 3 extracurricular books and arranges for us to visit the World Trade Exhibition, and discusses with us what we learned during the summer vacation. This greatly changed my original vision of work. Another thing that has benefited me a lot is that Everwide’s employees are very friendly to our work-study students, because they will enthusiastically teach us not to understand the problem, and will not scold if we make a mistake, and will patiently teach again. This feeling makes us feel very warm, so it makes us more daring to ask what we don't know and learn more. In Everwide, I have seen many systems to assist everyone in teamwork. On the one hand, mistakes can be prevented, and on the other hand, better efficiency can be obtained, so it’s no wonder that everyone’s working atmosphere is pretty good. Before coming to the internship, the instructor once told me that Everwide is a happy company. After the internship, I really have this personal experience. I am very grateful to the company for providing this opportunity, allowing me to absorb work experience, and also let me know many friends, thank you colleagues who have been taking care of me.

─ Author: Mr. Yi-Xuan, Yi

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