top of page

Everwide Newsletter No.226


Experiment § Hardening penetration of two-component silicone

Single-component moisture-curing silicone (RTV1) makes the moisture hardly penetrate because of the surface hardening. Therefore, when customers need deep injection applications, we always recommend two-component silicone. Two-component silicone rubber is divided into two types: addition molding and condensation type. Also, molding often has the problem of catalyst poisoning, which makes it impossible to harden. Therefore, for some applications, we will recommend customers to use condensation type two-component silicone. Condensation-type two-component silicone gel uses a catalyst to promote the reaction, affected by air humidity and application depth. Sometimes, customers still ask why the silicone gel is not dry? According to experiments, this phenomenon will be wholly hardened as long as it is left for a few days. Let's take the FX0665 product as an example: Figure 1 shows that when the depth is 0.5cm, it only takes one day to harden fully. However, if the depth reaches 2.0cm, the surface will set, and the bottom will not dry. This phenomenon is not an abnormal resin, but the reaction has not been completed (Figure 2). Let this resin stand for two to three days, and it will harden completely (Figure 3). Suppose a little water is added during the mixing process to allow the silicone to undergo a hydrolysis reaction. In that case, the reaction can be accelerated, and the hardening speed can be shortened from three days to one day (Figure 4).

─ Author: Mr. Zhe-yong, Lin

 

Activity § Re-evolution of the internship system

Every year, two shifts of students come to the factory for internships. The number of applicants this summer has increased sharply. We will do our best to provide 18 places. In addition to the labor experience, students can see the resin production process. In the past, we provided some instrument courses. This year we plan to introduce the quality systems ISO9001, 14001, OHSAS18001, TS16949, and TTQS. I hope to give them some enlightenment about the job. It is not the only thing we want to do. Since July of this year, interns will also take a test at the end of the training to organize what they have learned here. I believe that at the end of the summer vacation, everyone will have a great result, and all the hard work will be worth it.

 

Knowledge § Why is silicone poisoned by catalysts?

The silicone that hardens at room temperature can be divided into condensation type and addition type. Condensed silicones rely on moisture to carry out the hardening reaction. Most of them are single-liquid, commonly known as RTV1. This type of silicone is relatively free from catalyst poisoning, but there is a problem with the depth of hardening. The risk of catalyst poisoning is molding silicone, which uses platinum catalysts, which will be affected by phosphorus, sulfur, amines, and heavy metals (such as lead, copper, iron, tin, zinc, chromium, cadmium, mercury), etc. Influence, resulting in incomplete hardening, or even no reaction at all. The room-temperature-hardening addition molding silicones are two-component systems, commonly known as RTV2, which is easy to distinguish from RTV1. However, some room-temperature-hardening condensation silicones can also be made into two-component systems, so they will not be poisoned by catalysts. In other words, the single-component silicone that cures at room temperature will not have the problem of catalyst poisoning, and the two-component silicone that cures at room temperature may have the problem of catalyst poisoning.

 

Living § Pineapple season

When I was a sophomore, when I came home from a holiday, Dad Qiu suddenly asked: When did you graduate from university? I didn't care about this issue now, though that Dad Qiu cares about it because there are so many sisters in the family; they often confuse our grades. Later, I learned that Dad Qiu, who had been in the car motor repair business for more than 30 years, was about to retire and become a farmer. When he was free, he would take Mother Qiu around to see if there was suitable farmland. Not long after I graduated, Dad Qiu bought a farmland piece with a loan to grow pineapples. My impression of pineapple is that it is prickly and easily hurt. I asked Dad Qiu why he grows pineapple? He said: Fruit trees take 3 years to bear fruit, which is a bit long; vegetables have to catch insects, but he is afraid of insects; there are many mosquitoes on bamboo, and I am worried that the lady will not go to the fields to help, and the water supply of that farmland is insufficient, so I can only not to be afraid because it is a drought-enduring plant. I remember that the first batch of pineapples was harvested around the Ching Ming Festival. The market price was low. Dad Qiu was reluctant to sell it at a low price and had to find a way to sell it himself. In addition to setting up stalls at nearby tourist attractions, I also followed Dad Qiu to drive a truck to sell, and finally sold out the first batch of pineapples. After the settlement, I found that only pineapple seedlings, fertilizer, strange hands (for land preparation), machines, and other expenses could be flattened. If it is sold to the broader market, I am afraid it will lose money. At this time, Dad Qiu only said indifferently: Farming is healthy. Besides pineapples, Dad Qiu also planted some bananas, bamboo shoots, guavas, and seasonal vegetables next to the farmland. There are as many as 4 or 5 types of bananas and bamboo shoots. In addition to satisfying our appetite, we also have a place where we can get close to nature.

─ Author: Miss. Jia-Ying, Qiu



23 views

Related Posts

See All

Comentarios


Related Products

bottom of page