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.


      熟女一区二区| 国产精品亚洲婷婷99久久精品| 久久精品人人妻人少妇| 久久亚洲精品日韩蜜桃| 亚洲精品成人在线91| 丰满美妇少妇猛烈进入| 亚洲欧美日韩一区二区三| 亚洲黄片高清在线观看| 国产成人一区二区青青草原| 亚洲不卡av一区二区| av一二三区在线播放| 国产精品自产拍在线观看av| 成人熟妇无套内射视频| 国产中文成人av在线观看| 91精品推荐在线观看| 亚洲天堂免费一二三四区| 无码精品久久一区二区三区| 美女很黄很黄在线观看亚洲一 | 一区二区三区不卡中文字幕| 亚洲乱码中文字幕综合69堂| 国产自产视频一区二区三区| 久久久久国色AV免费观看性色| 国产成人午夜精品福利| 男人精品一区二区三区| 麻豆视频传媒入口免费| 久久欧美一区二区三区四区| 国产精品专区欧美专区| 国产成人91亚洲精品| 久久精品一区二区三区卡通| 亚洲AⅤ永久无码精品AA| 国产日韩精品在线一区| 五月婷婷激情六月开心| 肉欲av一区二区三区| 国产在线 | 中文| 亚洲熟妇av一区二区三区| 久久亚洲精品国产av| 无码人妻一区二区三区免费看| 丰满人妻一区二区三区无码AV| 国产黄色大片免费网站| 人妻伦理一区二区三区| 成人影院免费观看在线播放视频|