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2017年10月15日4 分鐘

Everwide Newsletter No.258

更新日期:2021年7月26日

Experiment § Adhesive for ribbon screen printing technology

We often receive gifts in very exquisite ribbon packaging. These ribbons are often printed with bronzing logos, symbols, or blessing characters (Figure 1). How are these things made from? I believe that not many people know about this. First, use screen printing to print UV resin on the ribbon, expose and cure it. Using the heated metal printing plate to make bronzing paper pass through temperature and pressure, thermos-printing using UV resin applies to the printing character. There is a hot melted resin on the back of the bronzing paper, transcribed set on the UV resin (Figure 2). Ribbon screen printing resin needs to have the following characteristics: 1. It must be flexible; 2. It must have a three-dimensional effect; 3. It must be able to bronze. Figure 3 shows the UV resin screen printed on the ribbon after hardening. The suitable UV resin can make the hot stamping character glossy (Figure 4). Unsuitable UV resin will lead to the poor bronzing effect: uneven surface, no three-dimensional effect, poor bonding between the foil and UV resin... We are developing products that are suitable for ribbon screen printing. We believe that soon, our products will hide in the gifts you receive.

─ Author: Mr. Wei-lin, Zhang


Activity § Anti-explosion lighting system update

In the early days, our manufacturing department used ordinary fluorescent lamps, powered by white PVC wires. Later, to strengthen the protection, we used PVC plastic pipes to lay the pipes, and then embed the wires in the pipelines. Recently, the authority required us to replace all the lighting equipment on the manufacturing site with anti-explosion lamps and switches to avoid electrical sparks, chemical vapors, or high-temperature surfaces that can make fire and explosion. Although the use of solvents in our factory is very low, and highly volatile matters are rarely used, it is still a worthwhile improvement to reduce the probability of disasters. We invite professional engineers to carry out the pipe layout project on the day off, and now, it is close to completion.


Knowledge § Is the higher thermal conductivity better?

Pursuing high thermal conductivity has become a myth. Every customer asked, what is the thermal conductivity of this thermal paste? First of all, we must understand the role of thermal conductivity in the heat-conduction formula: Q = K*A*△t / LQ: heat loss through conduction (W); K: thermal conductivity (W/mK); A: cross-sectional area of ​​thermal conductor (m2); △t: the temperature difference between the two ends of the heat transfer path (K); L: the length of the heat transfer path (m). When A, Δt, and L on the same condition, when the thermal conductivity K is bigger, the heat dissipation of conduction Q is also bigger. The way to improve thermal conductivity is to increase the proportion of thermally conductive powder. It will make the thermal paste very sticky, or the usage of large particle size powder will increase the distance between the heating element and the heat dissipation element (L becomes larger), and the effect of heat conduction will decrease. For example, using 5µm powder to make a thermal conductivity paste with 1 W/mK thermal conductivity, the thermal conductivity will be much better than using 50µm powder to make a thermal conductivity of 2W/mK. According to the formula, the thermal conductivity of the former is five times that of the latter. This example can prove the importance of good conduction and heat dissipation (Q). Besides thermal conductivity (K), the thermal paste's thickness (L) between the heating element and the heat dissipation element is also the key; it is often ignored.


Living § Sous vide

Food is the God of the people; besides pursuing the delicacy, eating healthy is often becoming the focus. For healthy food, safe and fresh ingredients are essential, and cooking methods are also a major focus. And the most popular cooking method in recent years is the "Sous Vide." Simply, after putting meat and vegetables in a bag to vacuum, place it in water to cook for a long time at a constant temperature, so it is also called the low-temperature vacuum-sealed method. Choose a specific temperature and time adjustment according to the different ingredients, and cook within the protein denaturation temperature range, so that the moisture and nutrients can be fully retained in the food, and it will be tender and juicy. The first time I came into contact with the Sous Vide was when I was in college. As a foodie, I certainly wanted to try it. But at that time, the household for the Sous Vide machine and the vacuum-sealed machine was so expensive. The cuisine restaurant was highly privileged. The laboratory oven, the thermostatic water bath is not very hygienic. I had to overcome difficulties and go to the food material store to buy the simple dial thermometer and fresh-keeping bag (Figure 1). Put the ingredients into the fresh-keeping bag and leave a small gap to insert into the straw to suck out the air as much as possible to complete the vacuum. Fill up the 80% of Tatung electric pot with water, put the thermometer, and start heating; when the temperature is reached, it will manually stop, and when it is too low, continue heating. The temperature is under control, and the cycle lasts about 15-20 minutes for two hours. Use your brilliant idea to solve many problems. When I came to Everwide, there were too many ideas, from using electric cookers to make high-temperature and high-humidity environmental tests to self-made UV-DSC. The golden brains of my colleagues always amaze me and benefit a lot. The Sous Vide steak is delicious; it is worth trying (Picture 2).

─ Author: Mr. Zhi-hung, Wei

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