男人看的网站婷婷久久,国产诱惑人的视频在线观看,亚州熟女一区二区三区,欧美激情丰满熟妇护士,国产精品久久av观看,久久国内偷拍综合视频,日韩不卡免费在线视频,成人美女福利在线观看,久久久亚洲精品一二三区,午夜福利一区二区三区久精品

<sub id="xzaay"></sub>

  • <rt id="xzaay"><small id="xzaay"></small></rt>
    <rt id="xzaay"></rt>
    <label id="xzaay"></label>

      Let's understand the nature of epoxy in epoxy tubes

      Editor:浙江和泰新材料股份有限公司 │ Time:2019-11-19 

      The epoxy tube is made of electrical alkali-free glass fiber cloth impregnated with epoxy resin and processed by hot pressing in a baking and molding mold. The cross section is a round rod. The glass rod has high mechanical properties. Dielectric properties and good machinability. It is suitable for use as insulation structural parts in electrical equipment, and can be used in humid environment and transformer oil.


      Let us understand the nature of epoxy in epoxy tube


      No matter what form of water-based epoxy resin and water-based epoxy curing agent is selected, the water-based epoxy system that has practical application value is a dispersed multi-phase structure. It consists of water-based epoxy resin, water-based epoxy curing agent, and water. Phase composition, its film-forming mechanism is different from that of ordinary polymer emulsions such as acrylic emulsions (condensation and film formation, physical process), and is not exactly the same as the film-forming of solvent-based epoxy. In solvent-based epoxy systems, Both epoxy resin and curing agent are dissolved in organic solvents in the form of molecules, and the system formed is homogeneous. The curing reaction proceeds between molecules, so the curing reaction proceeds relatively completely, and the cured product formed is also homogeneous. .


      Waterborne epoxy is a multi-phase system. Epoxy resin and curing agent are dispersed in the water phase as a dispersed phase. The cross-linking and curing process is a process of internal diffusion and cross-linking between particles during the evaporation of water. The degree of epoxy curing depends on four factors:


      a) Compatibility: The better the compatibility between the water-based epoxy resin and the water-based epoxy curing agent, the more favorable the internal diffusion of the curing agent particles and the epoxy resin particles, and the better the curing reaction;


      b) Particle size: When the particle size is small, the particles of the dispersed phase of the water-based epoxy resin and the water-based epoxy curing agent can sufficiently penetrate into the core to achieve a more complete degree of curing;


      c) Hydrophilic-lipophilic balance value: The hydrophilic-lipophilic balance values of water-based epoxy resin and water-based epoxy curing agent are close to each other, and a consistent coexisting and stable state is achieved in the water phase. If the difference is large, the hydrophilicity is stronger. The components will gradually accumulate in the aqueous phase, causing the resin phase and the curing agent phase to separate;


      d) Dispersion uniformity: In the state of multi-phase separation, the resin phase and curing agent phase can be evenly distributed in the water phase only through a certain mechanical stirring effect; (Epoxy is very important to stir and mix in the application) Some friends think that in the process of using oily epoxy, it can form a film with simple stirring or even without stirring. In fact, there is a big misunderstanding, because the oily epoxy used is dissolved by solid epoxy such as 75% of E- 20, even if no curing agent is added, the solvent can form a very hard dry film after the solvent is volatilized, but this dry film is cured without cross-linking of the curing agent, and becomes liquid after heating, and the dry film has no performance at all.


      中文熟女av一区二区| 青草视频午夜在线观看| 日本久久高清一区二区| 国内揄拍国内精品人妻久久| 国产精品熟女一区二区不卡| 日本伊人一区二区三区| 天堂在线观看免费av| 性色av成人精品久久| 亚洲自治区二色一区二区三区| 亚洲国产性感美女视频| 99久久国产宗和精品1上映| 亚洲AV无码一区二区三区观看| 久久国产精品快射视频| 国产欧美一区二区三区沐欲| 天啦噜国产精品亚洲精品| 国产av一区最新精品| 又大又湿又紧又爽A视频| 一区二区中文字幕人妻| 日本女优中文字幕在线观看| 亚洲熟妇熟色在线观看| 日本黄色一区二区三区视频| 亚洲人成电影网站色WWW两男一女| 亚洲国产精品色婷婷久久| 国产熟女高潮一区二区| 国产精品国产精品网站| 精品久久久久久久无码| 亚洲国产成全部在线精品| 日韩欧美精品在线一区| 挑战亚洲美女视频网站| 亚洲国产精品一二三区| 中文字幕第一页亚洲观看| 99久久免费精品视频| 国产精品乱码一区二区三| 国产福利一区二区福利| 国产亚洲精品ae86| 中文字幕一区二区三区人妻精品| 国产精成人品日日拍夜夜免费| 亚洲av有码一区二区| 天堂中文av在线资源| 久久免费看少妇a级黄片| 欧美日韩一区二区久久|