Everwide Newsletter-No.11

The micrometer body and scraper are made of contamination-resistant steel designed to have both erosion and wear resistance properties. The depth of the micrometer grooves varies from a maximum value at one end to a zero value at the other end. One or more groove depth scales are marked on the steel plate to measure particle size.

How to use the fineness meter: 1. Place the fineness meter horizontally on a firm and flat pedestal, according to various ranges, make the largest fineness scale face forward, and the 0 scales towards the operator. 2. Place the sample in the fineness meter's groove, let the sample overflow, hold the two ends of the attached scraper with your fingertips, and scrape the blade against the bottom of the fineness meter and the vertical plane of the length of the groove. 3. Press the scraper to make the center of the scraper perpendicular to the fineness meter, and scrape at a uniform speed in the direction of scale 0. 4. After scraping, observe the state of the sample surface scraped on the two groove surfaces from the oblique top, check the distribution density of the particles according to the particle distribution diagram, repeat the test, and obtain the average value.

Emulsified polyvinyl acetate resin uses polyvinyl alcohol to protect the colloid. After special plasticizing treatment, it can take into account the stability of the product and the softness of the hardened product. The film of emulsified polyvinyl acetate resin is transparent, has elasticity and appropriate hardness, and is suitable for application in various materials, such as furniture, wood products, polystyrene foam, laminates, building materials, unique components, etc. The main characteristics of emulsified polyvinyl acetate resin are: ① No organic solvent is added, which will not cause cracking and atomization of plastic materials. ②It is colorless and transparent after drying and will not cause pollution at the joints. ③The minimum film-forming temperature is 10oC, and the emulsifier contains polyvinyl alcohol. The main functions of emulsified polyvinyl acetate are: ① When used as an adhesive, please apply evenly on the adhesive surface, apply a little pressure, and place it under pressure for 3 to 12 hours, and the resin will harden. ②When used as a caulking agent, the maximum strength can only be exerted when the water volatilizes and the color of the resin changes from white to transparent and colorless. The actual drying time of the emulsified resin depends on the rate of water volatilization. It will be affected by the following factors: ① ambient temperature, ② ambient humidity, ③ ventilation conditions, ④ thickness of the adhesive coating, and ⑤ properties of the object material. Hardening conditions require final confirmation with actual items and conditions.

How is shrinkage due to hardening reactions measured?

During the hardening process of polymer materials, volume shrinkage or expansion will occur due to the change of the distance between molecules (in most cases, shrinkage). During the hardening process, the weight of the polymer does not change, so the change in density can be measured to calculate the volume change to obtain the shrinkage rate (density = weight/volume, D = W/V = g/cm3). Using the principle of buoyancy, the density before colloid hardening (D liquid) and the density after colloid hardening (D solid) were measured, respectively.

Shrinkage rate = (V liquid-V solid)/V liquid=[(W liquid/D liquid)-(W solid/D solid)]/(W liquid/D liquid)

Since W liquid = W solid = [(1/D liquid) - (1/D solid)]/(1/D liquid)

=[D solid-D liquid]/(D solid) = 1- (D liquid/D solid)

FC011 light-curing resin is developed to fix and bond different bonding materials. Under the irradiation of ultraviolet light, the resin reacts rapidly and can be integrated with the base material, resulting in excellent bonding strength. It is a very reliable photo hardening resin. FC011(1) has the properties of toughness, shock absorption, and thermal shock resistance and will not be degummed after long-term use. (2) It can react with the substrate to form a bond and exert a high-strength adhesive force. (3) It can be applied to various materials and widely solves the difficulty of following.

In order to explore human nature, the landman incarnates as a hawker selling rice dumplings. The land public has set a special price: a small bowl of glutinous rice balls with five corners and a large bowl of glutinous rice balls with triangles. After a whole day of selling, only one innocent child bought a small bowl of glutinous rice dumplings from the landman with five bucks, and the others bought a large bowl of glutinous rice dumplings with three bucks. The land public was a little confused and a little sad. He did not understand that eating a small bowl of glutinous rice dumplings with five bucks was a good and cheap deal. Why did everyone "enough to eat enough" to exchange triangles for a large bowl of glutinous rice dumplings? The above is a story from the book "Taiwanese Folk Tales" that my mother bought me when I was in the first grade of elementary school. I forgot the ending. I do not know if the landlord sent a mysterious gift to the child, taught him some special powers, or made him become an immortal? However, I was deeply impressed by the confusion and sadness that the landlord felt about this matter; I was often vigilant against myself and did not make any moves that would make the landlord sad. As I get old, I feel that the test of human nature is everywhere. When consumers want "value for money," there will be producers who "cut corners." When everyone is rushing to the dollar store, that is when the black-hearted goods flow freely. As long as everyone intends to eat a big bowl of dumplings with a triangle, the above situation of mutual restraint and mutual growth will inevitably exist. When I recalled this story, I suddenly thought of a question from another angle: "In a society where everyone buys a big bowl of rice dumplings with triangles, what kind of person is the Land Association considered?" Answer: (1) Too much money Nouveau riche; (2) business people who are good at marketing; (3) idiots who are cunning with calculations; (4) others. In my opinion, the affiliated societies for the first three answers are indifference, utilitarianism, and ruthlessness. The landlord will soon have to go into exile, and there is no way to bless everyone. For those who do not know about the metaphor of the landlord, there is a convenient way to understand it. To simplify, the dumplings are eaten in small bowls, and you can taste them lightly. Eating too many glutinous rice balls is not easy to digest, and it is easy to get an upset stomach.

─ Author: Dr. Ming-xu, Li, Everwide Chemical